Luftnachrichten Abteilung 350


The Luftnachrichten Abteilung 350, abbreviated as OKL/Ln Abt 350 and formerly called the, was the Signal Intelligence Agency of the German Air Force, the Luftwaffe, before and during World War II. Before November 1944, the unit was named as the Chi-Stelle Ob.d.L., which was often abbreviated to Chi-Stelle/ObdL or more commonly Chi-Stelle. The founding of the former agencies of OKL/Ln Abt 350 dates back to the year 1936, when Colonel Wolfgang Martini instigated the creation of the agency, that was later established on the orders of Hermann Göring, the German politician, military leader, and leading member of the Nazi Party. Right from the beginning, the Luftwaffe High Command resolved itself to make itself entirely independent from the German Army in the field of cryptology.

Background

The LN Abt 350 was one of a large number of regiments which were named in that series, but there were several related regiments, which dealt with intelligence-related matters, of one kind or another. These were as follows:

Radio Defense Corps

History of operations in the west

Outbreak of the war

General

The effect of the outbreak of war was immediately felt by Chi-Stelle, in so far as all participating nations began to transmit the majority of their messages in codes and cyphers. Thus the evaluation of the contents of messages was made more difficult, although the organisation of Allied air forces, as such, that were already known, could be built up from intelligence on hand. Newly activated units were identified on the basis of existing tables of organisation. In the early months of the war in France only the movements of bomber and reconnaissance units could be determined since the fighter arm could only be followed by monitoring RT traffic.
The Invasion of Poland only last 18 days and was over to quickly for signals intelligence to play a part in it. However the Invasion of France and Invasion of Russia were preceded by a long preparatory period in which the respective Leitstelle found time to familiarise themselves with Allied procedure. Also by virtue of existing reserves, it was possible to concentrate the bulk of available resources on a single opponent.

Organisation

With the outbreak of the war only two battalions were established for use in the west: W-Leit 2 and W-Leit 3 and these were immediately committed. Both battalions had substantial difficulties to contend with, e.g. the shortage of officers was so acute that two intercept companies had to be commanded jointly by one officer. The position of the Leitstellen at Luftflotte Headquarters was a difficult one. Contributory factors was the complete unfamiliarity of the Leitstellen commanders with Signal Intelligence processes that included the strict security of own processes that the Chi-Stelle operated on. Even the flying units of the Luftflotten that were interested only in combat, regarded signal intelligence with much scepticism. The first break in this wall of distrust was achieved through the results of monitoring Allied RT fighter traffic.
In order to combat raids by French fighter aircraft on Germany. Individual intercept detachments were formed from the companies under W-Leit 3 to intercept the fighters RT traffic. On their ow initiative these detachments sought contact with German fighter units, to whom they communicated their observations by telephone. As the French fighter pilots talked excessively while flying, a great deal of valuable information was provided to traffic intercepts captured by German fighter control, especially since the detachments were equipped with Direction finding equipment that could pinpoint French fighters. The successes of Staffel and Gruppen working together with signals detachments in shooting down Allied aircraft to such an extent that Chi-Stelle became an esteemed agency whose intelligence was valued by the German Fighter Command.
The British night attacks on Germany began in the first months of 1940. Usually the British bombers flew to Le Bourget during the afternoon, and then took off from there at night, flying as far as the Prague area. Their route was followed closely by intercept stations W-Leit 2 and W-Leit 3 through taking DF bearings on air-to-air traffic and from pilots, speaking freely. They flights were for propaganda and training purposes, during which leaflets were dropped.
Neither in the six-weeks long Battle of France was it possible for Chi-Stelle or signals to distinguish themselves, owing to the speedy sequence of events. An exception was the intercept detachments of the 9th and 10th Companies under W-Leit 3 that worked in cooperation with German fighter units. At the end of the Battle of France, W-Leit 3 moved to La Celle-Saint-Cloud, the 9th Company to Deauville, the 10th to Saint-Malo, W-23 to Brest and W-33 to La Celle-Saint-Cloud. W-Leit 2 had already moved during the campaign with W-12 to the vicinity of Brussels and from there dispatched an intercept platoon to Wissant. The platoon covered No. 11 Group RAF in England. At times the large scale operations of the German Luftwaffe against England in autumn 1940 were directed from its intercept room. Here the technical importance of signals became indisputably apparent for the first time. Unfortunately W-Leit 2 was transferred to the East, early in 1941 and the platoon subsequently fell to the lot of W-Leit 3. Requests for personnel and equipment were continually ignored by W-Leit 3, which could not overlook the fact that its own intercept companies had been overshadowed by this platoon.
The tactical successes achieved by signals intercept that benefited fighter units also bought a more favourable relationship between signals and headquarters and this included Chi-Stelle, that became renowned. Of course the unfortunate internal politics played with the key positions of the service and this prevented a steady growth in the unit. The Luftwaffe at that time contained too many rough edges and contradictions, and despite of all its supposed veneer of modernity, it was still burdened with too many inveterate Prussianism to be capable of instituting radical changes directly following great successes. Thus, those young successful soldiers did not become the decisive factor in the next period of signals development, but rather the old reserve and career officers, unfamiliar with signals work, who held key positions by virtue of their rank and age and whose paralysing and often destructive influence was characteristic of the Signal Intelligence Service in the west.

Training

Although civilian employees had been trained in Army intercept stations during peacetime, the signals training of military personnel was totally neglected. Therefore, when the number of personnel increased tenfold in the early months of the war, newcomers received little training and had to develop their own ideas and methods independently. In order to remedy this intolerable situation, a signals school was created under the control of W-Leit 3, in which radio operators and evaluators were given the experience necessary for their profession.

Mid 1940

General

The surprisingly quick collapse of the Allies in the French campaign of 1940 offered little opportunities for signals to expand. Few staff officers realised the importance of immediate evaluation of intercepted message traffic. Tactical and strategic evaluation of signal intelligence was in its infancy, on the one hand because competent signals officers were themselves not aware of its possibilities and on the other hand, because headquarters were orientated to regard Chi-Stelle in the same breath as they did secret agents.

Organisation

An insight into signals development in 1940 can be determined from the following facts.
The Signals units located in the west comprised:

Locations

The W-Leitstellen were located either at or near Luftflotten headquarters. The fixed signals intercept stations moved more slowly. Signals companies were already established on the coast of Netherlands, Belgium and France. Each company and fixed intercept station had a WT and RT platoon as well as an evaluation section and its own DF unit.

Evaluation

Each intercept station and signal company analysed its allotted material that led to considerable duplication of effort and in light of the results obtained, a waste of personnel and equipment. Two reports were forwarded daily by wire to the W-Leitstelle and to Referat B. Daily logs were forwarded by courier to the W-Leitstelle and also to Referat B to be evaluated. In spite of this duplication of work, the individual companies were allowed to operate independently, their independence varying with the ability of the company commander and the evaluators. Competition and jealousy were known to exist.
Daily reports and other report types at this time contained only descriptions of the radio traffic, including list of Call signs and traffic identification. Detailed explanations were seldom given. In addition, intelligence from other sources was furnished to the Chi-Stelle by the Ia-Dienst staff of Headquarters while the W-Leitstellen received their collateral intelligence from the Ia-Dienst of the Luftflotten.
Problems concerning Allied fighter control, installations and functioning of Allied radar, use of call signs by RAF fighters and bombers were still unsolved.
Intelligence from both the special radio section of the German Post Office, the Pers Z S and from the Procurement Division of the Luftwaffe dealing with radar intercept and jamming was so shrouded in secrecy that in the case of W-Leit 3, only one commanding officer and one technician were permitted to have access to these reports.
In the Calais-Boulogne-sur-Mer area that was controlled by Luftflotte 2, the concentration of signals intercept stations and Naval DF units brought about closer liaison with the commanders of fighter units and with Naval formations.

Communication

The communication channels consisted of:
The land-line system was the prototype for lines later installed to operational units and was constructed by a construction battalion that was part of the Luftflotte. It proved a disadvantage to Luftwaffe Signals to not have any construction platoons of its own. The W-Leitstellen were equipped with their own telephone and teletype exchanges.

Liaison

Referat B disseminated information to the Luftwaffe Operations Staff. Missions within the operations context of their respective Luftflotten was assigned to the W-Leitstellen by the Chi-Stelle. The Luftflotten reserved the right to request additional intelligence with that defined context as created by the Chi-Stelle.

Mid 1941

General

The Luftwaffe signals organisation growth was the main accomplishment in 1941 and consisted of:
As the unit grew a large number of problems manifested compared to mid 1940 including a number of problems that still remained unsolved.

Locations

The fixed signals stations personnel with the exception of the Husum intercept station left their installations and quarters in Germany and moved to the occupied areas in the west. The signal units of Luftflotte 2 remaining in the west were subordinated to W-Leitstelle 3 and this became the central evaluation headquarters for all signals units in the west. To facilitate liaison with the Chi-Stelle, Referat B moved to Asnières-sur-Oise in October 1940.
At the same time the W-Leitstelle 3 began to exercise an influence on the DF sections of the companies. High frequency Direction finding units from the northern tip of Denmark down to Biarritz were lined into several DF networks each covering a large area. The radio and direct land-line communications of the DF units made possible a large scale and extremely efficient DF system. Although the respective companies were by degrees being brought up to strength in both men and equipment, nevertheless the DF evaluation section of W-Leitstelle 3 continued to retain control and direction of the greatly increased DF missions. This development was furthered by the success of this large DF system in plotting British reconnaissance aircraft over convoys in the Atlantic. W-Leitstelle worked in close cooperation with the Atlantic Air Force commander, Generalmajor Karl Koller and the submarine commander at Lorient.
Each company slowly developed its own speciality. Wissant and Urville expanded into fighter-warning centres which were most important for the protection of German reconnaissance aircraft. Originally individual units were informed by telephone of messages that were of interest to them. However the demands upon Luftwaffe signals from these units quickly grew so immense that individual service could not be given to each staff, group or squadron. Therefore, a fighter-warning and air situation broadcast was established. All the positions of British day and night-fighters that had been determined, were made known by means of the broadcast. The unit command posts decoded these messages and gave instructions to their aircraft in flight. By this means numerous German reconnaissance aircraft received information as to when they had first been plotted by the British Air Raid Warning Service, where patrolling fighters would intercept them, what types of aircraft had been sent to intercept them and so on. Not only reconnaissance units but also German fighter and bomber units, Air-Sea Rescue Service units, Schnellboot and convoy units made use of this broadcast. From the end of 1940 until the Allied invasion the broadcast facilitated this difficult task for all aircraft and ships in the Channel area.
In November 1940 the RAF Fighter Command began to re-equip their fighters with VHF. Beginning with the control stations and squadrons of 11 Group, one group of traffic after another gradually disappeared. At that time Germany paid dearly for their neglect in not researching VHF intercept techniques and their persecution of radio amateurs early in the war. The only available VHF DF receiver, known as ‘’Victor’’ proved to be unsuitable because of its short range. The development of the ‘’E’’ receiver, which had the correct band spread, had not yet been completed. The collapse of the German warning service on the channel coast was imminent. Only the use of the French ‘’SADIR’’ VHF DF receiver beginning in February 1941 saved the situation for the Luftwaffe. As the British Fighter Command had not changed their call signs at the same time as their equipment was changed, the traffic of the two most important groups was available for interception. Had the Allies changed their call signs the Luftwaffe would have been forced to undergo a long wait until a suitable VHF DF device was invented and a suitable organisation evolved to take advantage of it.
The French ‘’SADIR’’ VHF DF device proved to be excellent enabling both ground stations as well as aircraft clearly being heard within a range of 150-200Kilometres. Beyond this range, reception depended greatly on atmospheric conditions. Problems with its use by German forces still existed, particularly with the aerial. At first the ‘’SADIR’’ was used with a horizontal Dipole aerials, made by troopers themselves and placed directly on the set. Then directional aerials were tried and later aerial poles bent upward on each end greatly improved reception. In addition conic and mattress-type aerials were tried out. In spite of these experiments it never became possible to increase the range, especially in the case of ground stations.

Evaluation

The creation of the Meldeköpfe, the construction of HF and VHF DF systems, liaison with headquarter staffs and other units, all brought new aspects to the field of final evaluation. Liaison was also established with the Dulag Luft in Oberursel.
Daily and monthly reports were divided into tactical and technical sections. The tactical reports included a description of Allied air activity, while the technical part was a systematic compilation and identification of all intercepted traffic.

Communication

Signals liaison officers at command posts and higher headquarters were included in the communication network.

Liaison

From autumn 1940 a signals liaison officer was assigned to the advanced command post of Luftflotte 3 in Deuxville. Liaison officers were also assigned to the 2nd and 3rd Fighter commands, to Atlantic Air Command and to Fliegerkorps IX. Unfortunately the initial selection of liaison officers were found to be completely unsuitable with the result that liaison only began to work smoothly only after many changes in personnel, including the eventual assignment of this work to thoroughly experienced technical sergeants.
The headquarters that were interested in the tactical Signal Intelligence received their reports directly from intercept companies and out-stations. An exception to this was the fighter-warning and air situation messages. The W-Leitstelle 3 devoted itself increasingly to final evaluation with the exception of intercept messages which were of concern only to the Kriegsmarine. W-Leitstelle effectively competed with Referat B with both of these organisations issuing monthly reports.

Mid 1942

General

The monitoring area of W-Lietstelle 3 included Denmark, German Bight, Netherlands, Belgium and Northern France and western France. There were also three out-stations in Spain which had been set up during that period. That area was too large and could no longer be taken care of by the staff of a single battalion. Moreover, the battalion became too large, both as to the number of men and also in the number of subordinate companies. This resulted in the decision taken in December 1941 for a proposal for the activation and organisation of a Signals Intelligence regiment.

Organisation

The Royal Air Force having organised heavy bomber formations was beginning to attack Germany. While the Luftwaffe command was combining offensive units within Luftflotte 3 that had greatly reduced its strength through continuous action, there also began an expansion of the defence system with Germany that was conducted under the command of Luftflotte Reich, first against night raid aircraft units and later against aircraft flying on day raids.
With the expansion of the war into fronts, the importance of Luftwaffe signals in the west increased. Luftflotte 3 became increasingly dependent on the intelligence reports from the Referat. The radar organisation that by 1942 had pass the experimental stage and was now active units. In the same year the unit Signals Regiment West that was assigned to Luftflotte 3 and organised into three battalions.
In the middle of 1942, the regiment consisted of 3 battalions with a total of 14 companies. In addition the Norway battalion consisted of 5 companies. The approximate strength was 3000 men.

Operations

A sharp division developed between the evaluation and intercept companies, except where evaluation problems arose from special tasks or a geographic location made an exception necessary. Within the battalions a rigid centralisation had already been established due to the existence of the evaluation companies. These companies were in agreement with Referat B regarding the fundamental aim of tactical and operational intelligence, specifically maintaining knowledge of the deployment and organisation of the Allied air forces.
In general each battalion developed independently according to the ability of its commanding officer and his advisors. The 1st Battalion was far ahead of the other two battalions on the exploitation of intelligence. The battalion commander devoted himself to the task of thoroughly covering the Allied heavy bomber units and plotting their routes. He recognised early the wide scope of signals and the Radar Service and the use that could be made of them. The monitoring of heavy bomber units was a field in which the German defence organisation was also greatly interested. Fliegerkorps III that later became Jagdcorps I was operational in the defence of Germany. The battalion was given special considerable in matters of logistics. The aircraft warning and plotting system developed in Meldeköpfe 1 was an exemplary one and following the creation of the Command Post for Radio Evaluation was adopted by all Luftwaffe signals units.
At first the poorly commanded 2nd Battalion was not capable of establishing its own Meldeköpfe. Its companies established command posts which passed their reports to Meldeköpfe 1. The jamming company also worked independently of the battalion, its jamming equipment deployed along the coast for use against British ground radars.
The least changes occurred in the case of the 3rd Battalion which continued in its accustomed manner of working.

Evaluation

The form of messages and reports was fixed. Occasionally in a specified sector, reports covering a longer time period were made in order to clarify a certain event or to prevent certain developments.

Communication

Fig 11
As the diagram showing the liaison and message channels for 1942 indicates, the wire network was further expanded. In addition to the individual teleprinter lines within the companies, several telephone lines were available and running from the switchboards of the evaluation companies to the intercept companies. Additionally there was one or two line networks connecting to the signals liaison officers at headquarters. The diagram does not take into account the various direct lines from the companies to the liaison officer, for the purpose of achieving the minimum of delay.
The whole construction of the communication network was founded on the principle of passing on intercepted traffic as quickly as possible. A delay of more than 2 minutes could not be tolerated. This expansion made the building of large telephone exchanges:
The regimental exchange finally comprise 5–6 FD 16's with about 150 trunk lines and 250–300 local drops. In addition to the normal company telephone exchanges, in the case of the 8th company and the 55th company, DF control communications had to be installed. The regimental teleprinter exchange had 6–8 lines to the Luftwaffe exchanges in addition to lines to the companies and signals liaison officers. There were three secure teleprinters for secret messages and 8–10 for secret communications. Altogether about 500–700 teleprinter messages were handled daily.

Liaison

The liaison of individual evaluation stations with other units and headquarters varied greatly. In the case of the 1st Battalion its forces were concentrated. The operational and tactical work was incorporated in Meldeköpfe 1. As command of the defence of Germany was the responsibility of Fliegerkorps III, whose presence in the area made it unnecessary to send liaison officers either to that headquarters or to its divisions, the company commander and his assistants advised those headquarters from the Meldeköpfe. It was only necessary to assign an officer to Luftflotte Reich to protect signals intelligence interests there. A liaison officer was also assigned to the Fighter Command in the Netherlands.
The 2nd Battalion was unable to furnish its own liaison officers. The reports of this battalion were either passed to Meldekopf 1 or sent directly to the liaison officers. Later a separate message centre for radar reports was established in the Meldeköpfe 1 area in Corfu North.
The liaison officer sent to Luftflotte 3 Headquarters by the 3rd Battalion did the staff work. The officer had to compile operation reports in addition to those of the individual signals stations and had to contribute to the daily combat report. In ways the officer's work competed with that of certain technical staff advisers on the Luftwaffe operations staff.
Due to the feebleness of the regiment, the signals liaison officers were able to establish their own channels for operational messages. They received reports directly from the intercept stations, DF controls and radar intercept stations; this should have been the duty of the Meldeköpfe. In this way the headquarters lost patience with the regiment and the well-received unity of the signals intelligence unit was weakened.
The signals liaison officer with the Atlantic Air Command was actually an officer from the 16th company in Brest, that was responsible for RAF Coastal Command. Here less importance was attached to the general air situation and the growth of the enemy air forces than to the operations of the Coastal Command in the Bay of Biscay and the Atlantic.
Liaison with B-Dienst was the responsibility of Luftflotte Headquarters. B-Dienst was considered very timid and for a long time had prohibited telephone conversations pertaining to signals. In the first years of the war, intercepted messages from the British air raid warning network Nora and enciphered using Loxo was found to contain sufficient information to predict the timing of air raids.

Mid 1944

General

In the two years previous to the invasion, further expansion had taken place. From a modest start a radio intelligence agency for the defence of Germany was created. Its mission was to plot aircraft and monitor radar within the borders of Germany. Thus Luftwaffe signal intelligence was able to give an appreciation British and American Air Forces in the United Kingdom. It became an essential component of the German defence system and of the German Fighter Command particularly.

Organisation

Although the battalion in Norway also had in the course of time to turn to the east, using the RT station opposite Murmansk and stations in Finland, its chief task remained the monitoring of 18 Group of RAF Coastal Command, for the protection of the German Convoy route along the west coast of Norway. The fixed intercept station in Husum was the connecting link between the W-Leitstelle 5 in Oslo and Meldeköpfe 1 regarding heavy bomber raid intelligence. In the event of an invasion, the intercept station in Husum would be subordinate to the 1st Battalion.
The Signal Regiment West carried out all signal intelligence assignments in the west. It maintained the opinion that only a single and closely knit organisation in the west could intercept and evaluate in a uniform manner. The Luftwaffe Operations staff and Luftwaffe Reich planned to place a certain emphasis on the expansion of the defence of Germany. The support given to the 1st Battalion in the Netherlands and the resources at the disposal of signals battalion Reich, surpassed by far those available to the units under Luftflotte 3. Two questions were frequently discussed at the time:
Firstly, owing to the lack of qualified people who had an understanding of the situation, there was a separation of radio intercept from radar intercept. The regimental commander was unable to combine the radio and radar intercept platoons in his company, even though he was aligned with the wishes of the Chief Signal officer of the Luftwaffe. Individual incompetence, exaggerated sensibility towards the feelings of the battalion commanders, impassiveness and reluctance to act prevented the exercising of any distinct influence on the part of regimental HQ. Only the commander of the 1st battalion had combined intercept channels and forming a concentration of all forms of signal intelligence and who was subsequently entrusted by the Hermann Göring with the creation of a central signal intelligence flash report evaluation section called the Command Post for Radio Evaluation , located in Treuenbrietzen.
Radio intercept stations were established all over Germany on an accelerated schedule. They were used to plot the routes of heavy bomber formations which were bombing German cities with increasingly heavy attacks.
Meldeköpfe 1 was originally created to serve Jagdkorps I. As its successes became more widely known, Luftflotte 3 also wanted to have a Meldeköpfe. As a considerable part of the signal regiment was stationed in Paris where the Luftflotte Headquarters was located, a second Meldeköpfe was created using the resources of the 2nd Battalion. Meldeköpfe 2 specialised in covering Allied tactical air forces as well as plotting the routes of aircraft in the German-occupied areas in the west. Later it covered the Allied invasion air forces from Limburg.
The enormous strain put on signals forced the different signals units to cooperate with each other to optimize resources. The 1st Battalion was again the most efficient. Therefore, the companies of the 3rd Battalion that used VHF sets had to intercept RT traffic from heavy bomber formations for the 1st Battalion and to place their large HF DF networks at the disposal of the 1st Battalion. This network was used to DF messages from the RAF giving wind conditions over Western Europe. In Germany the original Meldeköpfe 1 established its own DF organisation with the help of the Safety Service Regiment Reich.
The expansion of the radar organisation within Germany necessitated the transfer of Meldeköpfe 1 and this became urgent when Jagdkorps I moved from Zeist to Treuenbrietzen. Therefore, the commander of the 1st Battalion was entrusted with the creation of a central Meldeköpfe to cover the whole of Germany. This was the ZAF. The ZAF was directly subordinated to the Chief Signal Office of the Luftwaffe and who had direct authority over the Meldeköpfe and over the evaluation of radio intelligence where a uniform method of plotting bombing raids was concerned.
From the beginning of 1944 two problems had come to the fore for the regimental commands:
The regiment had a distinct order that in the event of a move it would not interrupt operations of the intercept companies or the Meldeköpfe. All staffs had agreed that the units of the regiment must be maintained in the event of a retreat on the part of the Headquarters. However, only after several months of discussion had taken place could a statement be obtained from Generalfeldmarschall Hugo Sperrle Commander-in-Chief in the west, authorising the battalion commanders to give withdrawal orders to their units in the command area. Only in the event of a definite locate emergency could signals personnel be pressed into combat.
Regarding the question of motorizing static units, the regiment was unable to obtain any further allotment of vehicles in spite of the fact that it had only two fully mobile companies.
In the middle of the 1944 Reichsmarschall Hermann Göring was considering placing radio intelligence directly under the command of Luftwaffe Headquarters. Such a decision would have been welcomed by all members of signals as it would have finally done away with the distinction between administrative and operational control, without changing the structure of the existing units.

Strength

The strength of the signals units in the west increased to approximately 5000 people in the course of two years. A third of these were women. The regiment with its three battalions, numbered 15 companies. In addition there were two battalions with a total of 10 companies that were specifically committed to Germany.

Operations

The strength of the companies varied in regard to personnel and equipment according to their tasks. Those companies engaged upon WT interception had from 20-50 radio sets. Direction-finding units were concentrated in so-called DF villages along the coast. Here were located DF units used for special company missions, as well as the DF units of the large network used by the evaluation company of the 3rd Battalion.
In the Netherlands and Belgium the only step taken was alternate sites located farther inland, although the units stationed in Brussels and The Hague were ordered to remain there. In France the 16th Company moved from Brest to Angers and parts of the 8th Company from Urville to Cambrai and Rennes. In case of necessity, the 9th Company was to withdraw to Paris. In Southern France the Radar Company and the 10th Company from Montpellier to Avignon.
After the landing of the Allied in French North Africa and the occupation of Western France, the 10th Company was transferred from the Channel coast to the South of France. In the middle of 1943 a VHF RT platoon was situated above Monte Carlo to monitor fighter units and later the Tactical Air Command. The primary mission of the company was to monitor Allied air activity in the Mediterranean Sea with a particular focus on the Gulf of Lyon. Working with the signals battalion in Italy, it was intended to be a warning centre for raids of heavy bombers on Southern France. The Radar Company was activated but never became operational. The evaluation of their results should have been combined with that of the 10th Company.

Evaluation

The 1st Company was the evaluation company of the 1st Battalion and conducted outstanding independent work in the evaluation of traffic from heavy bomber groups for Referat B. Referat B was particularly good in extracting intelligence from captured documents and equipment. Occasionally the Referat published a report on navigational aids which was esteemed as the most difficult work of signals.
The closes liaison existed between Referat B and the 5th Intercept station, the Army evaluation centre in France. Referat B also had permanent liaison officers at Dulag Luft in Oberursel and had a direct line from Referat B to the camp since autumn 1942. The questions of prisoner of war at Dulag Luft was greatly influenced by Referat B. Attached to the Referat were liaison officers from German fighter, bomber and reconnaissance units who placed their operational experience at the disposal of the evaluation unit. Additionally liaison personnel from the Weather Service and technical bureau of the Luftwaffe were assigned to the Referat.

Signal communication

The creation of Battalion Reich and the assignment of signals liaison officers to the divisions of Jagdkorps I made numerous circuits necessary both within Germany and from Germany to the occupied countries. The cabling requirements increased when the ZAF obtained an additional circuit.
At the beginning of 1944 radio stations were established by the regiment at all out-stations, command posts and companies. Each company had:
The Meldeköpfe was included either as part of the DF control network or with WT link between the company and the out-stations. In the case of line trouble, all tactical reports could reach the Meldeköpfe as soon as possible, and from their broadcast
as a flash report to interested HQs. The code used by the Meldeköpfe for enciphering the report consisted of a 1000 word as keys and a cipher table. The message was sent out on both Longwave and Shortwave in 5-figure groups.
The construction of DF and radar intercept station within the area controlled by the German military, made it impossible for each of the regiments 176 out-stations and 60 out-stations subordinated to signals battalion Reich to each have its own direct line. For this reason the Dente or operational connection was introduced. Using a code word to drive a physical audio synchronisation protocol, any conversation taking place over normal Luftwaffe telephone circuits could be immediately terminated and the line used to quickly pass tactical reports e.g. air raid type and duration.

Liaison

At the same time that the Jagd Divisions within Germany were created, signals liaison officers were assigned to them. It was no longer conceivable for the Luftwaffe tactical staff to be without a liaison function. In the event of a line failure, liaison with the Kriegsmarine and the Heer HQ and Luftwaffe signals was broadcast using radio.
The winter of 1943 and the first six months of 1944 were entirely under the influence of the impending invasion. In autumn 1943 a large preconceived map exercise was performed from the operational staff of Headquarters for the purpose of training the army in how to liaison with Luftwaffe signals to achieve the best results. It was intended to give not only an insight into the working methods and message channels utilised for signal intelligence operations, but also to portray the initial stage of an invasion and the difficulties that would likely arise for Luftwaffe signals.
The concluding of invasion preparations in England was accurately covered and reported. On the night before the invasion, Meldeköpfe 2 was able to give first warning about 2300 hours, without actually stating that the invasion was actually beginning. By 0100 hours, the unit was clear in its decision that a very large undertaking of a special nature had begun.

Course of the invasion

Shortly before the invagination the invasion the installations on the channel coast for jamming British radar were completely destroyed. DF and radar intercept sites were also the individual targets of fighter-bomber attacks. During the night before the invasion the intercept station of 8th Company was smashed to pieces by RAF Bomber Command.
On the day of the invasion the last platoon of the 8th Company withdrew to Paris, the 9th company moved from Deauville to Saint Germain also in Paris. DF and outstations in the theatre withdrew to the nearest headquarters after destroying their equipment. After the occupation of France, RAF Bomber Command refrained from switching on its Gee-H equipment until the aircraft had reached a longitude of 3° East, depriving signals of an advance warning of their arrival. After the American breakthrough at Avranches on 12 August, that was concomitant to Operation Cobra#Operation Bluecoat, 30 July – 7 August, the 16th Company and what remained of the DF units on the Atlantic coast were ordered back from Angers to Paris. As Paris was taken by the Allies on 25 August 1944, the entire regiment moved to Wich east of Nancy. By that time Referat B was attached to the regiment. After a short stay in the Lorraine area, the bulk of the regimental units withdrew to finally assemble in Limburg an der Lahn with the 3rd Battalion stationed in the Freiburg im Breisgau and the 1st Battalion stationed with Meldeköpfe 1 in Wiedenbrück.
As trucks were in short supply, a substantial collection of equipment had to be destroyed in the out-stations and barracks and within camps. In Wich, 60 trucks were found by chance, loaded with equipment and transported to the rear. About 300 receivers were lost during the retreat.
In Limburg, the concentration of several evaluation section in one place led to the creation of a single, large, regimental evaluation unit. Referat B had sacrificed a large number of its personnel to the newly created air support parties and the remaining personnel were absorbed into the new evaluation unit, but remaining as a military unit, Referat B.
The withdrawal in France had shown that the liaison between air and ground units had proved insufficient. For this reason VHF detachments were established at advanced headquarters. VHF detachments were also created for the protection of airfields of individual fighter wings.
Other detachments were sent to Army and Army Group headquarters to take signals broadcasts from Meldeköpfe 2 which in turn, serviced them with collateral intelligence.
While the regiment was occupied with its reorganisation in a location on the western border of Germany to which it had retreated, a new signals organisation was adopted by German High Command. The new unit called the Funkaufklärungs-Führer Reich was placed under the command of Oberstleutnant Rudolf Friedrich for operational command and Generalmajor Wilhelm Klemme for administrative command.

November 1944 reorganisation

Introduction

The dynamics of signal intelligence operations make it difficult to find any point of rest at which an accurate statement of organisation is possible. However, the several reorganisations of the signal service that occurred in 1944 to fill the needs arising throughout previous operations gave the service its final form.
In the spring of 1944, the first of these reorganisation took place. All signals units including the Chi-Stelle which heretofore had been placed
under the command of the Air Ministry, i.e. the Chi-Stelle Ob.d.L. were now the tactical command of Chief Signal Officer, 3rd Division Oberstleutnant Rudolf Friedrich.
This centralisation in tactical matters and the decentralisation in administrative affairs to the field command units led to difficulties in guidance and supply. As a result in the autumn of 1944, after an abortive order by Hermann Göring to unify all Luftwaffe signal units through combining all intercept, jamming and radio traffic units as part of Luftwaffe Signal Regiments. This new organisation unified all home and field units into independent signals regiments and battalions with numbers ranging from 350 to 359. Administration was centralised in the Senior Signal Intelligence Officer Generalmajor Wilhelm Klemme.
The final organisation provided for centralised control in the Chief Signal Officer instead of the Air Ministry. Under the Chief of Staff of the Chief Signal Officer, three divisions were established:
General Nafue III had administrative control over the Chi-Stelle and the commanding officer of General Nafue III was Oberstleutnant Rudolf Friedrich. Under the reorganisation of November 1944 the Chi-Stelle was redesignated Air Signals Battalion 350 abbreviated as OKL/LN Abt 350. Friedrich in his position of dual command, regulated the planning for the entire German signals service and as a representative of the Chief Signal Officer remained the supreme authority until the very end on all signals matters of decisive importance. Nominally, however, the administration of signals was the responsibility of the old retainer, Generalmajor Willi Klemme who was named the Senior Signals Officer. The Chief Signal Officer of the Luftwaffe, General Wolfgang Martini decided to recognise the claims of the fighter arm who required advanced warning of bomber raids and he proposed the creation of the office of Reich Defence Signals Intelligence Service in November 1944. All signal intelligence matters pertaining to the defence of the Reich were placed in the hands of Colonel Forster who was named Chief of the Reich Defence Signals Intelligence Service or colloquially the Reich Signal Intelligence Air Raid Warning Warning Agency. This structure can be seen in the Organization chart.

Staff

Among the subordinates of the Chief Signal Officer was the Chief of Staff Oberstleutnant Otto Rudolf Morgenstern who was responsible with executing the orders of General Martini and his duties followed three main lines of action:

Divisions

The three duties of the Chief of Staff were performed by three divisions of the Office of the Chief Signal Officer. The organisational pattern consisted in a separation of each division into four or five functional groups, each of which was in turn subdivided into sections.

Reich Defence Signals Intelligence Service

Establishment

The FAF unit, directed by Hans Forster, was subordinated to the Chi-Stelle for operational purposes and was an advisor to the Commanding General of Jagdkorps I.

Remit

The Reich Defence Signals Intelligence Service had the following responsibilities:
In the autumn of 1944 the Luftwaffe signals service was heavily damaged and it was assumed that Luftwaffe personnel who had been captured following the invasion would have revealed information to the Allies and this seemed to be more true as the British had become more cautious in their radio traffic.
The commanding general of Jagdkorps I, Generalleutnant Joachim-Friedrich Huth demanded that early warning of approaching enemy aircraft, particularly at night, should continue despite the loss of the French and Belgian sites.
To accomplish this objective, the FAF took the following measures immediately:
The Chief Signal Office was further requested to increase the number of radar observer companies as the commanders of existing companies were unable to control the numerous small radar stations that were already in existence.
By consulting with Joachim-Friedrich Huth, it was decided that the Chi-Stelle would be changed to specialise in the tracking of enemy bomber units. No particular interest was attached to enemy fighter cover. Nevertheless even in this situation, all measures were taken to use available information to the best possible advantage.
After the decision was made the reorganisation of the units in the west was started. The support of the Army and flying units of the Luftwaffe in the operational area had to be secured. It was the main task of LN Regiment 351 to furnish tactical intelligence concerning Allied air forces. After the detachment of the first battalion from the regiment, a new and rather complex reorganisation was necessary. The newly founded 1st battalion, consisted of four companies:
The previous 2nd and 3rd battalions were reorganised with additional companies. A 4th battalion was detached and assigned to Luftflotte Reich and later subordinated to Signal Regiment Reich and renamed to LN Abteilung 359. These peremptory measures were salutary as only the Signal Officer of the Luftflotte Reich had the means to construct the numerous jamming sets.
The 2nd Battalion operated between the River Main and the Swiss frontier. The 3rd battalion operated between the River Main and the North Sea providing intercept and DF stations in an area that overlapped the area of the 2nd Battalion. The battalions, LN Abteilung 356 and LN Abteilung 357 were responsible for radar and route tracking in the area of Germany.
At the order of the FAF High Command, the Meldeköpfe's reorganisation took place. Additional control stations were added to the Meldeköpfe network. The Meldeköpfe were renumbered as follows after the reorganisation of the ZAF.
Similar to signals evolution in the west, the radar infrastructure in Germany underwent a parallel evolution. Radar intercept centres were established. All radar DF bearings were sent to the centres to be evaluated. Later the LN Abteilung 356 battalion took command of these radar Meldeköpfe's.
To reflect the change nature of signals in the Western Front, the commander of LN Regiment 351 Major Ristow had considerable independence when it came interception and analysis operations. This was necessary to avoid any delays in the delivery of intelligence in the case of an emergency.
With the aid of the regiment, observations of enemy radar situated in France and Belgium were used to improve the tracking of Allied Aircraft.
Meldeköpfe 1 played a special role within Fliegerkorps XII and later Jagdkorps I. The commander of the first battalion of regiment west, recognised that the radar service would assume greater importance for the fighter arm and prepared the Meldeköpfe accordingly for such an evolution. Meldeköpfe 1 was the oldest of these units and became a model for all subsequent units and as the personnel of the ZAF has been drawn from Meldeköpfe 1 when it was created, a special relationship existed between the two units.
Friction arose between the FAF and the ZAF related to the tracking of allied fighter cover. As Allied air raids became more intense, from interwoven bomber streams covering Germany from the west and south simultaneously, it was impossible to handle the verbal announcements that were arriving into the operations room of the ZAF. Therefore a decision had to be made whether to concentrate on bombers or on fighters, since both could not be evaluated at the same time. The FAF insisted on tracking both fighters and bombers due to the importance fighter-tracking represented in determining intended targets. The predilection by training and tradition of the ZAF personnel was for bomber tracking. The problem was never solved, more so since the Luftwaffe intelligence facilities were rapidly smothered under the accumulating weight of the air power directed against Germany.
Meldeköpfe 3, having three radar intercept stations, was at a disadvantage compared to the corresponding battalions of the western regiment, as LN Abteilung 356, which was recently created and lacked experience. Improvement was a primary concern of the FAF. By transferring experienced personnel to the unit, it was noted that it began to improve.
The collaboration with Meldeköpfe 4 became ever more important. The raids from the south continued to increase in number and as the weeks progressed penetrated deeper and deeper into Germany. If the results were not always satisfactory, it was due to the disturbances of long wire lines. However, surprises out of the south happened rarely.
With Meldeköpfe 5 there was little collaboration on the part of the ZAF, as the eastern front contained no strategic air force activity of any importance.
In connection with the reorganisation of the western signal intelligence service, there was a review of all radar intercept stations. Due to the responsibility for logistics being passed from the Luftwaffe to the Reich Ministry of Armaments and War Production, by this point being directed by Albert Speer, the supply of materials to construct new stations proved extremely difficult, even as the demand for technical field equipment increased. To a certain extent, Regiment 351 was able to help itself, whereas Battalion 356 was unable to procure supplies and had to deal with an increasing amount of red tape. The establishment of separate radar observation posts in Germany often required waiting several months for supplies, in spite of the utmost urgency. The special radar centre of Luftgau VI in Münster that functioned to the very end of the war, developed the Naxburg radar. The Naxburg had several advantages compared to the Korfu radar set that was used in signals. The signals intelligence service mistrusted everything that did not originate with them. Only at the end of 1944 was the Naxburg radar generally acknowledged. When it was finally introduced, even into the ground observer organisation, the advantages of its use were clearly evident.

Command Post for Radio Evaluation (ZAF)

When the command post of Jagdkorps I was transferred to Treuenbrietzen, it became necessary to establish a signal intelligence unit that would aggregate all flash reports available from all Meldeköpfe into a single report. Extensive wire and radio communication nets from the ZAF to the Meldeköpfe and connected to the radar intercept centres and out-stations, were established. As well as the teleprinter connections and inter-office communication between the Jagdkorps I Command Post and the ZAF operations room duty officer, to ensure the best communication links.

History of operations in the south

Operations in the south

General

While the Luftwaffe signal intelligence in the west reached a higher state of development, it was in the south that it faced its greater challenge. This was true because it faced a foe as equally as aggressive and resourceful, an extremely varied physical environment and geographical extent of the Mediterranean theatre of war, wherein its operations were conducted.
In the west, signals intelligence enjoyed the advantages of the concentration of means, excellent wire communications, and proximity to the opponent, and technical problems were reduced to the minimum. In the south, the rule was a wide dispersion of installations, scanty wire communications and insecure transportation and supply routes, were common. Climatic and living conditions, especially in Africa and the Balkans, compared to those in the west, particularly in the Balkan regions, from partisan activities, all had a profound influence on signals.

Mid 1940

In the middle of 1940, the Signals Intelligence Service of Luftwaffe was marshalled almost entirely against Great Britain. Only the French and English traffic from Africa was observed, in the old peace-time manner, by the fixed signals station W-13, located in Oberhaching. Station W-13 was established in 1938 and was working under the direct supervision of Chi-Stelle, with its own evaluation section and DF network. Its reports were forwarded to Referat C in France.

Mid 1941

General
By the middle of 1941, the Luftwaffe was represented in the Mediterranean by Fliegerkorps X, that had been stationed in Norway, and transferred to Sicily in April 1941. From the beginning, Fliegerkorps X was conceived as a naval air arm. After the Balkan countries capitulated, it moved from Sicily to Greece and was later stationed in Crete. Luftwaffe signals were not involved in the Balkan campaign, but it was largely due to the work it had done previously that the Luftwaffe command possessed a thorough knowledge of the Balkan air forces and their deployments, enabling their quick destruction.
Signal Intelligence units that were created in the southern theatre were:
Organisation
Evaluation
Each of the signals units did their own evaluation of the intercepted traffic. The final evaluation of 9th Company LNR 40 was located with the intelligence operations of Fliegerkorps X.
At first, W-14 confined itself chiefly to an evaluation of the message contents, and the peculiarities of the different traffic, as most other units were doing at this time. After the arrival of the cryptanalysis platoon, the intercept of traffic was guided by two considerations:
  1. to increase the total quantity of messages available through the interception of networks, not previously covered.
  2. to intercept systematically traffic of tactical importance.
In those days, evaluation meant deciphering or solving a message and translating it into German. Every day a collection of solved messages was sent to Referat C and all other signals units in the south. All stations published daily technical intelligence reports on the results on evaluation, and monthly reports.
Signal communication
In contrast to the west, the south never had excellent wire communications. A direct line between Sicily and Berlin as well as between Athens and Berlin did exist, but even at the best of times, it was almost impossible to get through from Athens to Sicily. The non-existence of communications from east to west was the principal reason for the Referat moving back to Berlin from Paris. This Referat should have been even more important, as it was the only cypher bureau that received up to date information from both the eastern and western Mediterranean. Daily situation reports were sent to the Referat by those signals stations having the best teleprinter lines. The units in Sicily had their own internal wire net. When this facility was inadequate, flash messages and orders were sent by wireless telegraphy. Reports were sent by courier.
Liaison
From the beginning of the Norwegian campaign, the liaison between intelligence operations of Fliegerkorps X and the 9th Company supplying it with intelligence, was particularly close. This company's reports were not prepared by its evaluation section, but by intelligence operations. However, a general evolution in this direction would not have been advantageous to signals, as it would have lost its independence. The 9th Company was dependent on operations department to such an extent that operations, not the company commander, decided the units coverage. As W-14 and WO-313 also used to turn in their material to the operations Abteilung, and since the Referat was not alive to its responsibilities, the operations department of the Fliegerkorps alone could give a currently summary of the air situation in the Mediterranean theatre.

Mid 1942

General
The strong reinforcement of the RAF, and the growth of opposition generally in the Mediterranean forced the German High Command to tremendously strengthen the Luftwaffe in that theatre. For that reason, Luftlotte 2 was withdrawn from the Eastern Front in November 1941 and sent to Sicily. At the beginning of 1942 it arrived in Taormina. The following units were assigned to it:
Each Fliegerkorps had an attached signals company; the African Air Command had a signals platoon. An evaluation company W-Leit 2 was attached to the Luftflotte and became the centre of signals activities. By virtue of the expansion of the signals company in Athens, to which new personnel were constantly being added, the organisation was finally raised to the size and status of a battalion. This resulted in a distinct separation of signals organisation in the south. W-Leit 2 and its associated units became responsible for the area west of a line drawn through Capo Passero, Malta and Tripoli. W-Leit 2, Southeast was responsible for the area east of this line. The logical unification of the two battalions into one signals regiment was repeatedly considered, but failed due to bureaucracy.
Organisation
The great importance the Mediterranean Theatre had assumed by the middle of 1942 can be estimated from the fact that the number of personnel engaged in signals work had increased 500% over the previous year. An important step in the development of the signal service in the western Mediterranean was the transfer of W-Leit 2 from the Eastern Front to Taormina in Sicily.
Evaluation
The Leitstellen were provided to perform the evaluation function. But as the signals companies were given considerable assistance by the headquarters for which they worked, they prepared independent monthly reports for these HQs, in addition to supplying daily reports and flash messages. Still the two Leitstellen succeeded in retaining the final analysis function for themselves, and made the companies confine themselves more and more to instant tactical evaluation.
The development of evaluation itself was marked by:
The division of work between the two Leitstellen in the south was fixed by the differences in the traffic that each covered. The evaluation section in W-Leit southeast was organised on the basis of the opponents units with each section handling a tactical unit, e.g. No. 201 Group RAF, No. 205 Group RAF, 9th Air Force and the Desert Air Force. By way of contrast, W-Leit 2 divided its evaluation according to the source of the information, e.g. fighter RT,reconnaissance, bomber WT and air support traffic. In addition to these sections, there were additional evaluation sections for DF and captured documents. This division developed a high degree of specialisation; but in the case of W-Leit 2, whose officers were rather inefficient, led to an undesirable aloofness, which had an adverse effect not only on cooperation, within the W-Leit, but also on the outstations working under its direction.
Analysis of the 4-figure messages that were intercepted from point-to-point networks supplied excellent intelligence on the strength, order of battle, equipment and operations of Allied air units. Evaluation of this traffic was in large measure responsible for the rapid increase in the importance of W-Leit, Southeast. The combining of the intelligence gained through this source with air-to-ground traffic, provided a thorough picture of the air situation.
Beginning in June 1941, the transport traffic was also worked on by the contents evaluation section. These transport messages acquired additional importance the following year.
The 9th Company LNR 40 evaluation section was awarded a degree of independence due to the unreliable communications between Crete and the mainland. The evaluation section, that worked on the intelligence operations of the Fliegerkorps, was transferred back to the company in December 1941.
Signal communication
In order to derive operational benefit from the flash reports, both the operational units and the Signal Intelligence Service demanded that the latter have its own wire nets. The passing on of the daily signals reports, summaries, memoranda or signals matters, the exchange of cryptanalytic material, soon all necessitated a reliable and secure network specificity for the service. These requirements were agreed to by higher head headquarters, and in 1942, the communication facilities consisted of:
The wired network in Sicily was dependable and was used almost exclusively for intelligence. Only in the Balkans, with its permanent unrest, did radio communication prove indispensable from the start, with radio procedures and discipline optimised for the conditions.
Between the Chi-Stelle and the battalions, almost all communication was by land-line, as the Luftwaffe cypher device provided for radio communication was not suitable for encrypting the usual long reports, e.g. daily tactical reports, without a large number of additional message centre personnel.
Liaison
Even the smallest piece of intelligence, that signals were able to obtain from Allied air forces, soon made signals indefensible to the other units and headquarters in the south, where in extended areas relatively small forces opposed each other. The reliability of signals engendered great trust in it, and therefore, demand in combat units for signals liaison officers continually increased. Signals liaison officers were assigned to the Luftflotte, the Fliegerkorps and to the African Air Command. They made their reports to the intelligence or operations departments of the units, and particularly important messages were forwarded to the commanding generals.
Combat units commanders were briefed on the offensive and defensive possibilities of signals intelligence. Those who planned operations depended on the performance of signals that certain forces were held in reserve, especially in the Italian sector, which was only committed on the basis of signals reports. In addition to the fighters, whose control would have been impossible without the intelligence picture of the air situation provided by signals, bomber groups were also grateful for the signals fighter warning service, at that time based mostly on RT interception that enabled them to keep their losses tolerably low.
The liaison officer was the signals representative at headquarters. The officer received flash reports forwarded by teleprinter from intercept companies and the evaluation section and brought them to the attention of command, explaining the air situation at the daily conferences in the military intelligence office. The liaison officers were included in the distribution of all tactical reports. Technical signal data, e.g. call signs, were only passed on to them in exceptional cases. By virtue of their position, signals liaison officers exercised a considerable influence on tactical evaluation. At the same time, they were responsible for the process that ensures signals units received captured documents, PWI reports, photograph intelligence, and other military intelligence material, while passing to signals the particular requests of the combat units.

Mid 1943

General
In the year between 1942 and 1943, a rapid decline in military fortunes in the Mediterranean had occurred for Germany. Erwin Rommel's victories during 1941–1942 had brought the German forces close to Egypt. The turning points were the Second Battle of El Alamein and Field marshal Harold Alexander breakthrough at El Alamein and the Allied landings in French North Africa.
Two conditions greatly favoured this Allied undertaking:
The Allied landings in North Africa was the most successful use of deception of the entire war. The plan of making the landings appear to be no more than a large group of the usual convoy was considered masterful by Chi-Stelle. The activities of the diplomat Robert Daniel Murphy and his consuls in North Africa escaped German political notice as did the increased reconnaissance of the West African coast by Gibraltar-based aircraft. Murphy's activity was discussed at length in the German press at the time, but no military conclusions were drawn. Thus the only available clue that remained, the increase in aerial reconnaissance from Gibraltar, Freetown and Bathurst, was interpreted as signifying the approach of several large convoys for the Cyrenaican front. Reconnaissance over the African mainland was presumably carried out by carrier-based aircraft. However, no data on the RT traffic was procured by Luftwaffe signals, since it had no adequate bases for the interception of this traffic. The installation of a VHF detachment in the Balearic Islands had been requested by RT specialists, but this had never materialised.
During the year, the signals south unit was expanded significantly. Its defensive functions assumed increasing importance. This development always took place when:
At the time developments in the Mediterranean was characterised by:
Organisation
The German strategy in the south was driven by defeats and a steady accretion of personnel, moving from an offensive to defensive pose, and this dictated a more centralised signals organisation in the south, similar in design to the west, where that unit had reorganised in the middle of 1942. During the past year, the intercept companies had lost the last vestige of independence from the Leitststellen, and thus became more an intercept instrument of the evaluation company at battalion headquarters. Then a consolidation of the different types of evaluation executed by W-Leit 2 and W-Leit, Southeast, in relation to a higher command of intelligence evaluation, became urgent. To an increasing extent, the Chi-Stelle discharged its services to Luftwaffe General Staff, but its output was little used to furnish the service to the Officer in charge, W-Leit, Southeast. The obvious remedy was to unite the two battalions into a signals regiment. Instead, a signals liaison unit was assigned to Luftflotte 2 at the end of 1942.
Evaluation
A systematic improvement was possible only in the case of W-Leit Southeast, as W-Leit 2 was suffering from a lack of competent leadership at the time.
Evaluation of W-Leit 2 was still based on sources of intelligence, which not only lacked a coordinating factor, i.e. a final evaluation agency, but too long was allowed to elapse before new types of evaluation, such as that of the VHF traffic of American heavy bomber units, was undertaken. On the contrary, however, W-Leit 2 achieved noteworthy success in its evaluation of air support traffic in the North African theatre, in which field it was a leader.
Evaluation at W-Leit Southeast had progressed along the following lines during the year 1943.
As the solving of British 4-Figure traffic had become more and more difficult after November 1942, this task was turned over to Referat E of the Chi-Stelle in Potsdam. Therefore, the cryptanalysis platoon of W-Leit Southeast, returned to the Chi-Stelle. From this time forward, W-Leit Southeast evaluated the point-to-point traffic exclusively from its general characteristics. This was facilitated by the experienced log analysis section, where call signs and frequencies were identified on the basis of the cryptanalysis work that had been completed months before. Based upon this detailed knowledge, changes in call signs and frequencies did not confuse the signal intelligence picture, once they had been determined. When cryptanalysis was no longer possible, organisation and order of battle of Allied air forces in the Mediterranean were reconstructed from the monitoring of point-to-point traffic, while tactics, equipment and strength, hereafter were obtained from air-to-ground traffic.
By identifying the traffic of the Allied air raid warning and radar organisations in Africa, the evaluation section was able to open a new field of intelligence, that greatly supplemented the results of air-to-ground monitoring. Air-to-ground traffic and air raid warning messages formed the basis for flight path tracking in the Southeast.
The oldest source of intelligence for flight path tracking was WT air-to-ground traffic. Direction-Finding plotting made this possible. Its true importance became fully apparent at the time of the first B-24 Liberator raid on Ploiești. The WT traffic of the Liberators, that was especially voluminous during the return flight, was DF'd during the whole raid, with the result that landings of individual aircraft in Turkey, Cyprus, The Levant and Malta could be precisely determined.
Another source of flight tracking was the decoding of messages from Allied air raid warning networks in Cyrenaica. The approach flight of the heavy bombers units, on their way to targets in Italy and Greece, was invariably reported to tactical headquarters, either Luftflotte 2, Fliegerkorps II or Fliegerkorps X. By this system of early warning, a great number of aircraft were shot down on several occasions.
Later on, a much more productive and exact method of locating aircraft formations by evaluating the Allied radar networks, which reported every movement of Allied aircraft within range. In this manner, the evaluation section could determine the exact location and strength of the opponent's formations, and the method used to control them. Just as important to the German Commands early warning was the question of whether there would be an Allied raid or not. Signals could also predict this on the basis of tuning traffic from Allied bombers.
W-Leit 3 was superior to W-Leit Southeast in the evaluation of very high frequency RT traffic, owing to the more favourable location of its out-stations. The latter had neither advantageously sited out-stations, nor adequately trained RT operators. Both lacked trained radar operators with a technical background. In order to remedy this deficiency, personnel were continually sent to training courses, as well as receiving training within the battalion. The radar intercept evaluation section relied on personnel who were experienced in various fields of analysis.
Signal communication
The combat units were so accustomed to the monthly reports of the signals battalions, with their strategic intelligence on the Allied organisation, an order of battle, equipment, tactics and strength, that they were inclined to take these reports for granted. Only when early warning of impending heavy bomber raids enabled the combat units to score new successes, did the prestige of signals attain its former eminent status.
For political reasons collaboration with the Italian signal's intelligence bureau was being ordered by Senior Command. Nevertheless, because of the distrust on the part of the German signals bureau, it was limited to exchanges of unimportant material. The results of the evaluation were communicated to the Italian cypher agency Servizio Informazioni Militare via Brigadier General Vittorio Gamba, it was limited to an exchange of unimportant material. The results of the evaluation were communicated to the Italian agency only with the greatest caution. The Italian cypher agency, Servizio Informazioni Militare, was considered by the Luftwaffe to be a purely amateur undertaking, and especially in the field of evaluation, remained in its embryonic stages.
Cooperation with the German Army cypher bureau, the General der Nachrichtenaufklärung and the German Navy, B-Dienst proved excellent, although their remit was radically different. It was consolidated by personal contacts between the individual specialists. All relevant information of interest to other departments of the Wehrmacht was immediately telephoned to them and later confirmed by teleprinter. The corresponding Army and Navy officers were also put on the distribution list to receive the monthly reports of both signals battalions.
Miscellaneous
General
Owing to the difference in the military situation between Italy and the Balkans, development of the two signals battalions continued to expand in separate directions. First Pietro Badoglio Proclamation reduced Italy in the eyes of German to an outpost of Fortress Germany. This meant that the Luftwaffe no longer protected Italian cities, holding all fighters for the defence of Germany. This weakening of active fighter command brought an increasing demand for signals intelligence to guide passive air defence.
W-Leit 2 was charged with the duty of following the developments in the front that was forming against the German forces in Italy and the operations concerned with supplying it. This battalion shared the coverage of the western Mediterranean, Allied transmissions, supply traffic with 10th Co. LNR 3. After the occupation of Corsica in November 1942 by Italian and German forces, W-Leit 2 forwarded a very high frequency intercept platoon to Mont Agel to monitor Mediterranean Allied Tactical Air Force fighters operating from the airfields in northern Corsica.
From the time that the Allied forces landed in southern Italy, W-Leit Southeast took over coverage of the Adriatic whose coast was equally endangered by the threat of invasion. At the end of this period, the signals W-Leit Southeast company reached its maximum size and absorbed the signals company in Constanța, that was monitoring the Russian Black Sea Air Force. Also during this period, W-Leit Southeast prepared bases within the confines of greater Germany to which it might retire when the battlefront called for such a step. A change took place in the Luftwaffe organisation in the Balkans when Fliegerkorps X moved from Athens to France. In the spring of 1943, all Luftwaffe units stationed in the Balkans were assigned to Luftflotte Southeast.
Both battalions continued to provide flight path tracking of the Allied bomber missions that had moved to Foggia. The monitoring of these same Allied units became a principal function of Luftwaffe signals in the south. Despite unfavourable working conditions in the Balkans, a shortage of receiving sets, and a high proportion of second-rate personnel, W-Leit Southeast worked as efficiently and as performant as possible, due to what was considered, excellent leadership.
The organisation development of Luftwaffe signals in the south culminated in the consolidation of both signals battalions into one signals regiment with the regimental command being assigned to Ferdinand Feichtner.
Organisation
The combined Allied landings in Sicily and Italy on 9–10 July 1943, the increasingly untenable position of German forces in the Balkans, and the defection of Romania and breakthrough of Russian forces into this territory in September 1944, were all factors that determined the organisation and disposition of Luftwaffe signals in the south. Each of the battalions assumed a distinct and special development moulded by events in their respective sectors.
, where they reorganised before heading north.
The length of the war made it possible for evaluation sections to accumulate a great wealth of experience and highly qualified specialists. The exchange of intelligence data between the west and south were both accomplished through the Chi-stelle and by exchanging officers and evaluation specialists on temporary duty status. Seen as a whole, the development of the evaluation sections ran parallel. The emphasis in evaluation shifted more and more from the strategic to the tactical. This accounts for the increasing importance of the two battalions over Referat C in the final year of the war.
Both signals battalions had created a highly sensitive apparatus in well-integrated companies, out-stations, signals liaison officer and central evaluation companies. W-Leit 2 and Meldeköpfe Southeast had direct wire communication with the ZAF. Later Meldeköpfe Vienna became the information centre on flights of bombers from the south. Here, as in the west, a clear distinction was made between the tactical evaluation which the Meldeköpfe was engaged in and final analysis which was reserved to the evaluation company. Up until the last moment, signals intelligence kept pace with the development of Allied radar.
Signal communication
The decisive importance of tactical evaluation called for a developed and serviceable communication network. Whereas strategic intelligence could be forwarded to headquarters by courier, the tactical report was dispatched immediately and by electric transmission, either telephone or teleprinter to permit prompt countermeasures. In Italy, good communication was achieved by grouping intercept and DF stations and by establishing advanced signals control points. In the Balkans, signals possessed its first good land-lines in Pančevo thanks to Luftflotte Southeast. The Meldeköpfe in Pančevo had direct lines to all larger tactical air headquarters. Radio was an additional facility.
The VHF and radar intercept reports at first sent through separate channels were later dispatched over the same network. These networks were so organised that even in the event of an accumulation of messages, no one station would be overburdened.
After the Allies forced the withdrawn to Premstätten, the landline problem became acute for the signals battalion southeast, as the only lines of underground cable between Graz and Vienna were constantly being severed due to bombing attacks. For this reason, Attersee where there was an important junction of telephone lines, was along the line of withdrawal, was chosen as the next signals headquarters.
Liaison
From the time when bombing attacks on the Balkans and Southern Germany were intensified, signals liaison officers were assigned not only to operational headquarters but to combat units as well. All had wire and radio communications with both signals battalions in the south. Two or three times each day they were apprised of the air situation by telephone and imported this information at the planning and briefing conferences. As flight path tracking was perfected, the signals liaison officers gradually developed from assistants of Ic-Dienst to Ia-Dienst. Since the Air Raid Warning Service often failed to keep abreast of the grand-scale operations of the 15th Air Force, signals provided the only means of obtaining a reliable air situation report. Moreover, in contrast to the Air Raid Warning Service, signals could report strength and type of aircraft. In the war room of the fighter commands and the Jagddivision, a map of the situation as reported by signals was maintained, as well as one of the reports of the Air Raid Warning Service. This won many friends for signals at the Operational Command Posts. Units and Command Posts received signals predictions of raids and probable targets, sometimes hours before the raids began. Later on during the approach flights, signals furnished estimates on the strength, aircraft types and altitude of the Allied formation.
While during the first years of the war the relation between signals and Ic-Dienst grew close, it was relatively late before Ia-Dienst was awakened. Not until the decline of the Luftwaffe did operations grasp at signals information and pose questions and problems. It was especially interested in the tactics of Allied combat units, i.e. fighters, medium and heavy bombers and the modus operandi of Allied radar, jamming, equipment and other sundries. In order to make effective use of limited forces, operations conferred with the signals when special missions were planned. Likewise, the Fighter Warning Service was of concern to operations and the Chief of Staff. Questions of equipment, strength and deployment of the Allied air forces were of special interest to intelligence, while new intelligence of the opponents tactics received greater attention from operations.
Miscellaneous
All these factors led to the conclusion that the question as to whether a landing would take place depended more on political than military considerations. The undertaking never was realised in any form. Towards the end of the year, the radar equipment which had been concentrated in the Ancona area was redeployed on the eastern and middle sectors of the front. Likewise, units of the 8th Army that had been withdrawn were returned to the line. The Canadian XIII Corps was again placed under command of the British 8th Army and the area of tactical reconnaissance of the DAF was broadened to include the left flank of the Canadian Corps. The American 5th army transferred its spearheads back to the middle sector and pressed its attack in the same direction as previously. Through the redistribution of units, the 8th Army again become operational.

The German Collapse October 1944 to May 1945

General
The belated activation of the regiment did not increase the efficiency of signal intelligence in the south owing to the collapse of the fronts outside the borders of Germany and to the breakdown of communication within Germany itself. Despite the continued success of the Allies and the continuous withdrawals of Luftwaffe forces, the signals organisation that had reliable signals leadership in the south was able to make new successes. At the beginning of 1945, the Russians made their first penetration into Styria with Graz appearing to be threatened, the regimental staff, the evaluation company and one intercept company moved to Attersee. Following the Vienna Offensive, they were joined by Meldeköpfe 4 and the intercept companies previously located in the Vienna area. Likewise, out-stations in the south, west and east to be withdrawn because of Allied advances. The 2nd Battalion with two intercept companies moved to Stainach-Pürgg area.
In order to avoid capture when American units advanced into Salzkammergut, the regimental staff along with two attached companies moved to the area of the 2nd Battalion in steinach. After the German Instrument of Surrender documents had been signed, all the units attached to Luftflotte 6 moved to an internment camp in the Aschbach area where other elements of the 2nd Battalion were also gradually assembled. Women auxiliaries who had still not been discharged were either billeted in private homes or delivered to the women's discharge camp.
The 1st Battalion fell into the hands of the British forces in Canazei. Its women auxiliaries were interned in a camp near Bologna and the male personnel were taken to Naples under a misconception on the part of some RAF officers who had thought they had unearthed a spy ring.
Organisation
The creation of the regiment resulted in the combining of the two evaluation companies of the battalions into a single regimental evaluation company that was placed directly under the command of regimental headquarters, as was the Vienna Meldeköpfe. Each battalion comprised three radio intercept companies and one radar intercept company. Their duties were divided according to speciality, i.e. HF, VHF or radar, and geographical circumstances. A large evaluation platoon was attached to the 1st Battalion for the purposes of tactical evaluation. However, it remained assigned to regimental headquarters. In this way, all evaluation and liaison work was centrally directed
Receivers for the various intercept tasks were allocated as follows:
To this were added approximately 35 VHF receivers, bringing the total number of receivers operated by Ln. Regiment 352 to 205. The DF network comprised 23 High Frequency DF units and various radar intercept receivers, spread over 15 out-stations totalling approximately 100 units.
As the regiment was designed for mobile warfare, it remained operational, right to the very end, although restricted to an ever-narrowing area of land. When liaison with headquarters was no longer possible due to the collapse of the Command, the regiment commander with the help of the staffs of the VHF out-stations began to prepare a fighter warning service for the civilian population. When Franz Hofer, the Gauleiter of Linz requested the regiment to assign a signals liaison officer to his office. The surrender in the south brought an end to signals intelligence development in the south brought an end to development along the line.
Strength
The regiment had a total of only 350 women auxiliaries. After activation of the regiment, approximately 300 soldiers were transferred to signals units in the west and to other combat elements.
Signal communication

Operations in the east

Luftwaffe operations in the east

General
The overall mission of the Luftwaffe Chi-Stelle on Soviet Front was the interception and identification of the Soviet Air Forces radio traffic.
To accomplish this mission, it was first necessary to determine the types of signal communication being used by the Soviets. For both Wireless telegraphy and Radiotelephone, the high frequency band was used almost exclusively, the main exception being navigational aids, i.e. radio beacons, which were used on medium frequency. Until the end of 1942, only WT traffic was found, thereafter R/T was also employed, increased greatly from 1944 onwards. The Soviets used radar only to a small extent, beginning at the end of 1944. Almost all W/T traffic was encoded or enciphered.
From Germany's point of view, all Soviet W/T traffic could theoretically have been intercepted in one centrally located station. However, in practice, it was found, as is so often the case, that areas of , interference and natural barriers precluded such a plan and led to the establishment of numerous intercept stations all along the front.
Cryptanalytic problems were solved by the use of a relatively large number of people, not a few of which were capable linguists and could also be used to translate the contents of decoded messages.
A further problem occasioned by the expansiveness of the front was how to communicate the results of radio intelligence to those units and headquarters which could make the best use of it. The recipients of such intelligence were the Chi-Stelle, the operations of the Luftflotten together with their tactical units on the Soviet Front, and the signal intelligence services of the Army and Navy. Therefore, pains had to be taken either to site Chi-Stelle units in the immediate areas of such headquarters or at least in localities where good wire communications were available. Owing to the danger of interception, and delays caused by the necessity of enciphering messages, radio was considered only an auxiliary means of communication.
Problems encountered on the Eastern front were of such a nature that axiomatic Chi-Stelle procedures and processes could often not be put into effect as a whole, but instead usually as a compromise solution.
Development 1936 to 1941
Until the invasion of the Soviet Union on Sunday, 22 June 1941, interception of Soviet radio traffic was accomplished by several fixed outstations, each of which was assigned a prescribed area to monitor. In the summer of 1936, the first of these stations was established in Glindow, Berlin. During the year between 1937 and 1938, five further stations were established in Breslau, Pulsnitz, Bydgoszcz, Svetloye and Hirschstätten. Each of these fixed outstations did its own preliminary evaluation work, with final evaluation still undertaken at the Chi-Stelle. The stations were operationally controlled by the Chi-Stelle but administratively by a Luftflotten in whose area they were located. Thus the stations in Hirschstätten and Wrocław were assigned to Luftnachrichten Regiment 4, and the remainder with Luftnachrichten Regiment 1.
This policy was a great mistake and remained a point of contention with signals personnel throughout the war. It meant that signals units were subordinated to two unit commanders, an impossible situation from the military point of view. Frequent differences of opinion arose between High Command headquarters, each wishing to be considered as the authority actually controlling the Chi-Stelle. The situation was often intolerable.
It soon became evident that the personnel and equipment available for the monitoring of Russian radio traffic, that was becoming constantly more extensive and complicated, were not sufficient. The Russian methods of assigning call signs and frequencies became more and more complex. Special complications resulted from the fact that each Russian air army implemented its own signal procedures and cryptography standards, that according to the ability of the individual Russian signals officers, making it either more or less difficult for the Luftwaffe Chi-Stelle. There were some Soviet air armies, that owing to the incompetence or negligence of the signals officers, were looked upon with a sort of affection by the Chi-Stelle, while there were others whose traffic could only be analysed by bringing to bear all the resources that the Luftwaffe had available.
The most difficult task of all was intercepts from the northern sector or lack thereof. This was due in part to the fact that good land-line communications existed in the Leningrad throughout the static warfare in that region.
Owing to ever present personnel problems in the unit, the organisation of the Chi-Stelle unit during 1938 was not significantly expanded in the east. Luftflotten 1 and Luftflotten 4 requested their own signals intelligence unit, and each wished to receive signal intercepts directly from the units located in its specified area, and not via the Chi-Stelle. In order to meet these requirements, W-Leitstellen were created in the summer of 1938 in the immediate vicinity of each Luftlotte concerned. It was intended that these Leitstellen render interim reports to the Luftflotten while expediting the intercepted material to the Chi-Stelle for further processing. The personnel, cryptanalysts and evaluations were drawn from the fixed signals outstations, and to a lesser extent from the Chi-Stelle. This withdrawal of personnel from an already weak organisation suffering from chronic staff shortages caused a deterioration in the unit, without any commensurate gain to the new entities.
In the summer of 1939, the Leitstellen, the fixed stations and the mobile intercept companies on the two sectors were combined into signals intelligence battalions of the respective Luftlotte signal regiments.
When Germany invaded Poland, the Luftwaffe signals units in the east were ordered as follows:
At the conclusion of the Polish campaign, monitoring of Polish communications was discontinued. Its place was taken by the Balkan countries and Turkey, that were monitored from Vienna, Premstätten and Budapest.
In 1940 there were few changes. The fixed intercept station in Bromberg was moved to Warsaw. An intercept station and DF facility were erected in Kirkenes and the station in Budapest established a satellite outstation in Constanța. A new intercept company called the 9th Company of LNR 4 was activated.
This situation remained static until the invasion of the Soviet Union.
Signal Intelligence Regiment East organisation
was activated in September 1944. The need on the part of the subordinate signals units for a more unified operational and administrative chain of command was only realised up to the level of regimental headquarters, and then only realised up to the level of regimental headquarters, and then only on paper, as the Chi-Stelle still continued to traffic directly with subordinate units of the regiment. The regiment still suffered from divided control, operationally subordinated to the Chi-Stelle, and administratively to the Chief Signal Officer through Generalmajor Willi Klemme, who was not a specialist administrative officer.
Luftnachrichten Abteilung 353 was organised as follows:
All the battalions had numerous intercept and DF outstations along the entire front.
Owing to the Soviet advances, the regimental staff together with the 25th and 12th Companies moved to Dresden in mid-February 1945. From there as the Allies advanced into Germany, the group retired to Alpine Redoubt. In order to ensure the continuity of operations, a platoon of about 70 signals personnel were formed, comprising evaluators, intercepts and communication personnel. The platoon was fully mobile and carried the most necessary records and sufficient radio equipment for monitoring and communications purposes. It drove to Wagrain in the Northern Limestone Alps. The regimental headquarters and companies followed more slowly as they were not fully mobile.
In Wagrain, the 2nd and 3rd Battalions joined the regiment, so that with the exception of the 1st Battalion, that remained in north Germany, the regiment was reassembled.
After the surrender of Germany, the regiment proceeded via Zell am See and the Lake Chiemsee to the Luftwaffe concentration area at Aschbach in Austria. It was subsequently discharged.
Intercept and DF operations
In the autumn of 1940, the construction of a large Rhombic antenna system was started, and once in operation, was to orientated to the east and south-east, for the purposes of exploring the possibilities of a central high frequency intercept stations. It was put into operations only shortly before the outbreak of the war with the Soviet Union in 1941 and good results were obtained. However, it was never fully manned.
The distribution of intercept receivers by type for the various monitoring tasks was made on a basis of the preferences of the individual signals units. It proved most advantageous, wherever possible, to assign a complete monitoring mission to a single company or outstation.
Great use was found for the HF DF, A-10F that used an Adcock antenna type. However, for a war of movement, it had to be made mobile. A good DF baseline, as well as an efficient method of controlling the operations of the DF's, was essential to the accomplishment of the regiment's mission. Special care had to be taken in planning D/F control by radio, which of course involved the encoding and decoding of messages, every second counted. The assignment of several targets to one D/F station proved unworkable.
Cryptanalysis
The problem of securing sufficient and well qualified cryptanalyst personnel was at all times very great, since almost all messages, that numbered between 1000–2000 per day, were enciphered. To mitigate this problem, Chi-Stelle attempted to produce and train cryptanalysts itself. It was found that cryptanalysis skills were an inborn talent, and approximately one half of the personnel trained were proved useful. The chief reason why there were never sufficient cryptanalysts available may be laid to a tendency on the part of those men to specialise in certain types of codes and cyphers. It was also usually impractical to detach cryptanalysts to the various intercept companies, which in the interested of tactical evaluation would be advantageous.
Cryptanalysts were mostly employed in the W-Leitstellen, or in evaluation companies where they, as well as evaluation personnel, were in close contact of Referat E, that suffered a chronic shortage of staff. The introduction of new codes and new recipher table for old codes presented constant challenges for the cryptanalysts.
An average of 60% to 70% of the 2-Figure, 3-Figure and 4-Figure messages were solved. 5-Figure messages often required painstaking analysis, and when solved were often not read in time to be of any strategic or tactical value.
Evaluation
Excellent signal reception was absolutely essential to the Chi-Stelle. Experience from the Russian Front showed that the dissemination of intelligence from outstations to tactical aviation units had to be accomplished in a matter of minutes, and in some cases, seconds. For this reason, R/T stations of Signals Regiment East were located directly on the aerodrome of German fighter and reconnaissance units, and had direct wire lines to the fighter control centre. The out-stations were also tied to the teleprinter switchboards of the air bases in order that communication is maintained with the battalion and neighbouring R/T stations. The out-stations did not have the necessary means of installing their own telephone lines. They were furnished by the airbase commander. Radio links to the battalion were also maintained as a standby.
Liaison with the Army signals
As the external characteristics of Russian radio traffic were not sufficient to identify a group of new traffic as either Red Army or Soviet Air Forces it was necessary to maintain close liaison with the German Army cypher bureau, General der Nachrichtenaufklärung. Of primary importance was a liaison between the respective traffic analysis sections and for this purpose Non-commissioned liaison officers were frequently exchanged. During such periods when contact with the Army could not be maintained perhaps due to distances involved, the Luftwaffe Chi-Stelle was still able to identify traffic and execute traffic analysis.

Northern sector

Development up to the Luftwaffe invasion of Russia
In May 1941, Luftflotte 2 and its attached signals units, the 3rd Battalion of the Luftwaffe Signal Regiment was transferred to Warsaw. As the signals unit has no experience in monitoring and intercepting Russian traffic, the majority of the work was undertaken by the fixed station in Warsaw. The commitment of the Warsaw station increased again when W-Leit 2 was transferred to Italy in December 1942. To reinforce the Warsaw station, that was not fully prepared, W-Leit 1 in Bernau, seconded approximately one-third of its cryptanalysis and evaluation personnel to the Warsaw station. In the last half of 1944, the work of W-Leit 1 has attained such stature that its reports were forwarded by Referat D to the General Staff virtually unaltered.
Shortly before the beginning of the war with the Soviet Union, the 3rd Battalion of LNR 1 in Bernau moved with the Luftflotte to Königsberg. At the outbreak of World War 2, the battalion was composed of:
In addition, the Fliegerkorps subordinated to Luftflotte 1 had a signals company that monitored Russian air activity that was of specific interest to the unit. This company, was lacking in experienced personnel, was considered inefficient and to a great extent had to rely upon the support of the battalion. Much later in the war, it was amalgamated into the battalion.
These signals units were linked together by wired communications lines, to the Luftflotte that was only a few kilometres distant, the fixed intercept station in Warsaw, the Chi-Stelle station itself and the advanced echelon which had moved to East Prussia.
The order of battle and strength of Russian air units were already known from work done during peace-time, with all signals people being alerted during the night of 21 June 1941 as to what they might expect to find in Russian radio traffic. However, no change occurred in call signs, frequencies of transmission, codes or cyphers. Nevertheless, there was much chaos and confusion manifested in the great number of plain text messages that were received, the state of readiness gradually improved, but lasted for several weeks, and can be attributed to the continuous withdrawal of the Russians. Radio traffic was not as plentiful as Chi-Stelle wished, the reason being that there were satisfactory land-lines on the northern sector.
Operations
As Germany advanced into the Soviet Union in July 1941, Luftflotte 1 and W-Leit 1 moved to Dvinsk in Latvia. As it became increasingly evident that personnel and equipment were not sufficient for the task at hand, a request to increase the strength of the battalion was submitted, and in the middle of July 1941 a signals company arrived. This company had had previous experience in the East in 1939, and became operational in a few weeks.
After a three-week stay in Dvinsk, the battalion moved in Luftflotte 1 to Ostrov. Another company was created out of existing personnel, such that from August 1942 to December 1942, the battalion consisted of the following units:
A small intercept station in Mikkeli, with two out-stations, one in central Finland, the other on Lake Ladoga. This station was created after the entry of Finland into the war, and lengthened the DF base line.
Use was also made of the Finnish Signals Intelligence Office, Viestitiedustelutoimisto, whose work was considered to be of a high standard within the German cryptography community. The Luftwaffe station in Finland had either wire or radio links with W-Leit 1 in Ostrov. Additional DF equipment was established in the northern sector in order to obtain more favourable DF cuts. Some of these were placed in the area of the central sector.
During the period of transition, by augmenting its personnel in order to meet the increasing demands made upon it, the battalion was able to provide a flawless picture of the Soviet Air Force in the northern sector.
In early 1941, owing to administration difficulties and problems with billets, part of the Luftflotte, including the operations office, and the signals battalion, moved from their location in Ostrov to Riga in Latvia. In Riga, W-Leit 1 was located close to the Luftflotte, while the two intercept companies were positioned to the east of the city.
In autumn 1942, the Luftflotte withdrew to East Prussia, close to Kobbelbude, where the fixed intercept station was located. In February 1945, advancing Soviet troops forced the battalion to withdraw, via land and sea to the island of Rügen. The stations in Finland were closed, and the personnel withdrew. In January 1945, the battalion returned to Lübeck where it surrendered to the British Army.
Intercept
W/T interception was the most important in the first stages of the war. The area covered extended from the Arctic Sea to a region slightly north of Moscow.
In the autumn of 1942, the battalion started to take an interest in Russian High-frequency R/T, as this traffic was becoming more prevalent as the war progressed. Two R/T stations were established on German fighter airfields, one south of Leningrad, the other south-west of Lake Ilmen. This was done primarily to increase the rapidity with which these units received intelligence derived from Russian fighter traffic. However, it was found that from 1942 onwards that careful processing of RT traffic afforded valuable information on the strength and order of battle of Russian Air Force.
When the battalion withdrew to East Prussia in June 1944 these two outstations were left behind. A few months later it became necessary to establish another RT detachment in Courland. Later, the two out-stations left in Russia also withdrew to this area and continued operations even though Courland was cut off. Part of the personnel of these RT detachments later fell into Russian hands.
The battalion was responsible for covering the traffic of the Russian Baltic Fleet Air Arm. To assist in this task an RT detachment was placed aboard the German cruiser Prinze Eugen. This RT unit followed the activities of the Russian Baltic Fleet aircraft in order to warn German shipping of impending attack. This work assumed even greater importance after Courland had been cut off and was relying mainly on supplies by sea.
With autumn 1944 approaching, RT intercept had far surpassed WT in importance and was supplying 70%–80% of the intelligence obtained by the battalion. The Russian 1st, 3rd and 15th Air Armies used RT almost exclusively, which meant that at least one RT out-station had to be allocated to cover each of these air armies. Good communication between these detachments and the battalion were therefore of the essence.
Russian radar stations on the northern sector were located mainly in the Leningrad-Kronstadt-Levansaari area, and later on also along the Baltic coast, especially in the Revel and Kemel areas. Two radar intercept detachments were allocated to the battalions by the Radar Intercept Control Centre in Berlin, and these units monitored Russian radar activity in the Leningrad area from April 1943 to June 1944.
In March 1945, Russian radar stations began to use RT for reporting purposes. During Russian daylight fighter sweeps, the fighter control stations were informed of any German fighter reaction as revealed by radar. The signals out-stations monitoring this traffic were able to warn German aircraft of their impending danger.
Evaluation
Signals was a unique and therefore important source of intelligence to the Luftwaffe. Movements of Russian units, the occupation of airfields, the number of serviceable aircraft, and the location of supply dumps were determined from the monitoring of point to point traffic. Russian offensive intentions were also determined from traffic intercepted on these networks. Thus, for example, a Russian order to bomber units was intercepting ordering an attack on Shavli in Lithuania, where an entire German Panzer Army had been immobilised through lack of fuel. The signals reported this to the Luftwaffe, which provided fighters for the intercept of the Russian bombers, while Junkers Ju 52s dropped gasoline containers to the encircled army. Such signals successes occurred from time to time.
With the stabilizing of the northern front, the volume of Soviet radio traffic shrank. Nevertheless, a substantial number of messages still were intercepted daily. Signals were almost the only source of intelligence on the Russian situation, as agent's reports and other forms of intelligence were for the most part lacking.
On occasion, the signals battalion furnished intelligence to the Luftwaffe operations which went unheeded, e.g. in the autumn of 1941, when Germany was striving to effect a junction with the Finnish troops at Tikhvin, certain radio characteristics appeared in traffic on this sector that two weeks previously had been noted in traffic from Siberia. This was taken by signals intelligence as an indication that the Russian troops had been transferred in this short interval from Siberia to a sector south of Tichvin. The German command maintained that this was impossible, and did not react to this intelligence. The Russians attacked in great force and won a significant victory. The railway between Leningrad and Moscow was thus liberated by the Russians, and the Germans were forced to take up positions on the Volkhov Front, leaving the hedgehog redoubt of Demyansk to its fate. The junction with the Finns never materialised.
The signals station in Kirkenes which suffered with the Finnish SI station from auroral interference in its radio reception, nevertheless derived satisfactory intelligence for the German headquarters on the Kurmansk Front, especially that concerning convoys to and from Archangel. The latter was reported to the bomber units and the navy.
Similarly successful were the Finnish signals stations in monitoring the Finnish Front and the northern sector of the Leningrad Front. The Finnish and German signals worked in closest cooperation.
Liaison
Even before the start of the war, the commanding officer of the battalion had maintained unofficial liaison with the army and navy signals unit. Frequent visits were exchanged which resulted in a reciprocity of intelligence exchange. This liaison became closer as time went on, and all three branches of the Wehrmacht were able to give each other very important intelligence and avoid unnecessary duplication of work. Naturally, close liaison was also currently maintained with the other Luftwaffe signals battalions on the Eastern Front.

Central sector

Organisation and development
Before the start of the Eastern campaign, the fixed signals stations in Warsaw, W-21 worked on traffic of the Russian Air Force. When the war in the east became imminent, W-Leit 2 also was moved to Warsaw with Luftflotte 2 as reinforcement for the expected military operations. Up to the time of the move, W-Leit 2 had worked on British air traffic exclusively. Since it was inexperienced in Russian traffic, the full monitoring burden fell upon W-21 during the first months of the great offensive in the east. Conditions were made very difficult through lack of sufficient personnel and transport, as the campaign was then moving very fast.
W-21 and W-Leit 2 were moved from Warsaw to Minsk and later in October 1941 to Smolensk. In December 1941, Luftflotte 2 and its signals battalions were withdrawn and sent to Italy.
W-21 and the signals company of V Fliegerkorps had to cover all of the central sector Russian air traffic during the severe winter of 1941–1942, under the most difficult conditions. This coverage was performed from Smolensk. Owing to difficulties in administrations of the signals company of V Fliegerkorps and W-21, it was decided to combine them and form the Signals Battalion, East. At this time the Fliegerkorps V changed its name to Luftflotte east.
The signals battalion furnished all its intelligence reports to Luftflotte operations and worked directly under the Chief Signal Officer of the Luftflotte Staff.
In Smolensk, there was also a German Army signals regiment. This regiment covered Russian Air Force traffic. The coverage of air traffic by this regiment was even greater than that of the Luftwaffe signals intelligence. Every effort was made by the battalion to rectify this matter, and in the course of four months, this was accomplished through additional intercept personnel, transfer of the intercept site to an area of better reception, retraining of personnel, and reorganisation of and closer cooperation between the evaluation, deciphering and intercept elements. In September 1942, the army signals ceased monitoring Russian Air Force traffic, and all intelligence reports on the Russian Air Force were handled by the battalion.
The coverage of the battalion increased so rapidly that in a very short time, it was unable to cover all commitments without having again to increase personnel and equipment. These commitments arose from air-to-ground traffic, which up to this time had not been covered. It necessitated the creation of a DF network, RT outstations and a fighter warning service for German long-range reconnaissance. The ensuring requests for additional personnel and equipment were granted, in most cases by the Luftflotte in consideration of the importance of the mission and the value attached to signals reports. At this time the battalion compromised two intercept companies and one Evaluation Company. Only one of the companies was fully mobile, the other two had only a minimum of vehicles.
When the bulge in the German line in front of Smolensk was eliminated by the Russians, the battalion together with the now renamed Luftflotte 6 moved to Orsha in August 1943, and two weeks later again moved, this time to Minsk.
In Minsk, the battalion was ideally located in a large school and enjoyed excellent radio reception. The move was made in echelons, and coverage of Russian traffic was carried on during the move. The battalion functioned very smoothly, and took little time to become completely operational at the new location.
During October 1943 in Minsk, the battalion received the fourth company. This intercept company was formerly with a Fliegerkorps on the southern sector and was fully mobile. The addition of this intercept company enabled the use of fifty-five receivers on Russian WT traffic.
Each of the companies in the battalion had its allotted work. The 1st company was charged with all deciphering and evaluation. The 2nd company was assigned coverage of Russian air force point-to-point networks. Between 500 and 900 messages were intercepted daily, which were processed by the 1st company and read with 60–70% success. The 3rd company monitored Russian long-range bomber traffic. For fighter traffic, RT outstations of this company were attached to German fighter units and worked on at the latter's bases. The 4th company monitored the Soviet Air Defence Forces. This involved WT and RT traffic of the Russian fighter arm defending critical railway junctions and industrial centres. Also monitored were the flak and air raid warning networks, radio beacons, and radar. The RT outstations also warned German long-range reconnaissance aircraft of the approach of Russian fighters. The work in Minsk continued for about 10 months and was considered very successful.
In June 1944, the battalion moved with Luftflotte 6 from Minsk to Warsaw and in August to the vicinity of Łódź. While there, a fifth intercept company was added and the battalion was fully employed for another six months. .
The chain of command of signals battalions was generally changed several times during the war without attaining a satisfactory solution. Even the final reorganisation into signals regiments, with separate operational and administrative commands over them, did not prove at all successful.
The Fliegerkorps organisation and Luftflotten Ic operation, several times attempted to have the signals units serving them subordinated to them, rather than the signal corps, as these units were their prime source of intelligence. The realisation of such a plan which met with stiff resistance in signal quarters might have had a detrimental effect on the work of signals intelligence since a not inconsiderable part of this service devoted itself to the interests of combat units rather than to those of the Ic operations. Moreover, a signals battalion with its radio receivers, DF and other signal equipment would have proved too much of a technical problem for Ic.
Signals Intelligence Battalion East grew with an increased volume of Russian traffic, but from the very first was always able to solve the intricate problems presented. Lack of caution was in no small way responsible for many problems and the following illustrates the point. A certain German general, in a public interview, told the press that his success in breaking out of an encirclement by Russian troops was directly attributable to the knowledge of the disposition of opposing Russian forces, obtained from signal intelligence.
The effect of this interview was directly felt by the Chi-Stelle as such declarations inevitably brought about a complete change of Russian codes and cyphers. Despite these difficulties, signals were able to surmount all problems, owing largely to the fact that from the beginning it had followed Russian forces most closely, and could again pick up the threads, even following such drastic changes.
The battalion was always given the utmost consideration in its equipment and personnel needs, by the Luftflotte. Several times the Luftflotte commander himself came to the assistance of the battalion, owing to his great interest in the work.
Operations
Intercept cover
It was found that by giving the intercept companies a special area and type of Allied aircraft to work on, they became highly efficient and developed a real spirit of competition that proved most useful in this work.
The following types of traffic were covered:
The battalion had a total of 120 receivers, with the majority always in operation.
For WT intercept the radio receiver, Type A was used, however, there was a shortage of this types, so Type B was also used. Both of these sets were standard Luftwaffe equipment. Type B was not as efficient as the A in that it did not possess selectivity of the latter. For RT intercept, the high frequency C receiver was used. There were a few power orientated K receivers used on this sector, but these sets were not generally liked by the operators. It was found that better results were obtained by letting the operators pick their own type of set to work with, and this was done wherever possible.
Most of the radio sets were indented to be operated with dry cell batteries but for practical reasons, these were converted to wet cell battery operation by 100 volt storage batteries taken from vehicles. Two batteries were used for each set, one being charged while the other was being used.
DF operations
The battalion had five WT DF units, six RT DF units, three MF DFs, and three radar intercept DFs. This number was not deemed adequate for the work at hand.
Evaluation
A good communication system is most essential to signals work, in that it provides the means for immediate dissemination of all pertinent information. For security purposes, the use of radio must be limited. Excellent wire communication existed from the out-stations to the evaluation company, and from the battalion to command HQ. Each out-station had a teleprinter link with the battalion, as well as a standby radio channel. The battalion was equipped with a large telephone switchboard, with trunk service to outstations and command headquarters. The battalion had a number of direct lines, among which were lines to Luftflotte 6, Signal Regiment East, Referat D of the Chi-Stelle and to the nearest Luftwaffe exchange.
The battalion had its own teleprinter installation with both standard and secure teleprinter machines. These were tied into the Luftwaffe exchange and to the special signals teleprinter network. The latter network provided communication with the Chi-Stelle, regimental headquarters, and the other two battalions of the regiment.
During raids of t Russian long-range bombers, permanent telephone connections were established to the other signals battalions over a distance of 300-500Kilometres which were maintained for the duration of the raid.
A battalion signal officer was appointed to be responsible for the smooth functioning of all signal communication, including the distribution of cypher systems. This was usually the commanding officer of one of the intercept companies since these companies possessed the greater part of the signal equipment.
A technical inspector of the battalion staff, in conjunction with the radio repair sergeants of the intercept companies, was responsible for all signal maintenance and repair.
General comments
With local signals battalions
Close liaison between battalions was of extreme importance, as intercept cover overlapped. Through proper liaison many important points and valuable information exchanged on new traffic, unallocated stations to listen to and cryptanalytic solutions. The importance of immediate liaison was found e.g. when Russian bombers flew past more than one battalion.
German night fighter units
Cooperation with the Luftwaffe night fighter arm in the central sector provided good results. The signals battalion maintained a liaison officer at the night fighter control centre who received all signal intelligence data related to fixes, course, strength and probably targets of Russian bombers. Considering the paucity of Russian long-range bombing missions, the results obtained were quite satisfactory. For example, during a Russian attack on Tilsit that was closely followed by signals, German night fighters were able to shoot down 14 Russian bombers out of 100 that participated in the raid. During their next attack, the Russian bombers maintained the strictest radio silence, an indication that they realised the reason for their previous losses.
Long range reconnaissance units
A fighter warning service was maintained, similar to those in the west and south to advice reconnaissance crews of an impending attack from Russian fighters. The intelligence source for this service was the prolific Russian fighter R/T traffic, but compared to the fighter warning services in the other two theatres, it was considered rather primitive.
Day fighters
The support of German day fighters was one of the primary functions of signals on the central sector of the Eastern Front. For this reason, a policy of close cooperation was carefully nurtured on both sides. SIS out-stations, commanded by an officer and attached to fighter Geschwader or Gruppen, unusually maintained their operations room in the same building as the fighter control. By means of direct liaison between the commanding officer of signals unit and the fighter control chief, all operational matters to which signals might pertain were discussed. Signals served to instruct German fighter pilots on the combat tactics of Russian fighters and fighter bombers.
Luftflotte headquarters
In the east it was particularly difficult for the Ic operations of the Luftflotte to obtain information on the Allied situation. Reliable agents' reports were intermittent and photographic intelligence was seldom accurate, owing to excellent camouflage of which the Russians were masters. Moreover, it was dependent on the weather and towards the end of the war was rendered more difficult by the stiffening of Russian air defence. That the Ic, nevertheless, was able to boast an accurate picture of the Allied situation at all times was the result of the work of signals intelligence. Everything possible was done to further close liaison between the Ic and the signals battalion.
The battalion forwarded one of its most capable junior officers to the office of the Luftflotte Ic as a signals liaison officer. The latter usually had a direct telephone line to the battalion final evaluation section.
To assist the evaluation work, the Ic included the signals battalion in the distribution of all daily reports and appreciations prepared by his office. These included:
Russian airborne radio operators were interrogated by the battalion at first hand and all captured documents dealing with Russian signal matters were sent to the battalion. The furnishing of this important collateral intelligence to the signals battalions greatly facilitated its evaluation work. Those situations were obviated where the evaluation section may halt due to a problem that had already been clarified by accurate PW testimony. The analysis of Russian radio traffic, intercepted in conjunction with a German attack, was simplified if exact details concerning the attack were available to the German evaluation company.
All intelligence obtained by the battalion was passed to Ic by the signals liaison officer. At 6:00 pm daily, a secret signals intelligence report was prepared by a specially assigned and trusted evaluator. This report was sent by courier to the Luftflotte where it was available for the Commanding Generals war room conference, which took place each evening. Messages of tactical importance were passed to the Luftflotte as soon as they were obtained. On the basis of these daily reports, aggregate fortnightly report that emphasised long-range changes and new developments in the Russian situation during the period. The daily signals reports, together with other intelligence available, formed the basis for an Allied intelligence report prepared by the Ic and distributed to tactical units without revealing the sources of the material. 80% of the contents of this report was derived from signal intelligence.
The daily and fortnightly reports on the battalion were also sent by teleprinter to regimental headquarters and to Referat D of the Chi-Stelle.
Conclusions
Signals intelligence in the east was the prime source of Allied intelligence. Reports of the Russian Air Force units, special concentrations and warnings of impending attacks could always be timely and accurately stated. There were no important Russian attacks, that signals did not recognise early enough, that preparations could not be arranged.
Unit strength, availability of fuel and ammunition, serviceability of airfields and aerodromes as well as impending attacks on railways, bridges, factories and so on, were determined from solved messages. Signals on several occasions were able to predict in advance the time and course of America heavy bomber formations flying over the Russian lines, and also at which fields these units would land, e.g. Poltava.
The work of the RT out-stations with German fighter Geschwader was alone responsible for shooting down over 1000 Russian aircraft in the central sector.
Reconnaissance units often called the battalion by telephone after landing and expressed their thanks for the service rendered by the signals, stating that without this assistance they would have been unable to complete their mission.
During the first period of the war, reports from signals were so radical to High Command that they were initially distrustful of them, and made only the most cautious use of them. Later the situation changed, and came to believe in signals and radio intelligence implicitly, and hailed it as the most reliable and opulent source of Allied intelligence.

Southern sector

Organisation and development
Origins in the east
The development of the Luftwaffe signals units in the east began in 1936 with fixed intercept and DF stations which were mainly used by civilian personnel. The first operational territories were Czechoslovakia, Poland and the Soviet Union. Referat D of the Chi-Stelle was in command of signals intelligence in the east.
Development of the southern sector at the start of the invasion of the Soviet Union
After the Anschluss, and the annexation of Austria to the German Reich in 1938, the Heeresnachrichtenamt, the Austrian cipher bureau, was incorporated into the Luftwaffe. Austrian personnel were used mainly at two new stations, W-Leit 4 in Vienna and W-14 in Hirschstetten, Vienna. Stations in Hungary were organised in October 1938 under the cover name of Operation Stephen. In spring 1939, all signals intercept stations were organised as a battalion under command of W-Leit 4. After the forming of the Luftflotte 4 Signal Regiment, the 3rd battalion of the regiment became a signals battalion. At the beginning of the war, the following units comprised the battalion:
The signals company was reinforced by certainly experienced personnel from the fixed signals intercept stations. There was no central training of signals intercept operators. The battalion, therefore, instructed recruits during their training for the special tasks that needed to be undertaken. From the newly trained personnel, a second signals company was created in early 1940. Later a signals school for the battalion was established in Premstätten for the training for replacements. Radio operators allotted to the battalion received signals and cryptography training at the unit. The battalion covered the Soviet Union, Czechoslovakia until the invasion, Yugoslavia, Romania, Greece and Turkey. All these monitoring operations under the aegis of Luftflotte 4 were handled by an intercept company in Constanța. The main points of the observation focused on events that could ensure the success of military operations.
From Czechoslovakia, weather traffic, safety service networks and some artillery fire-control weather were intercepted. The order of battle of the Czech Air Force and the extent of occupation of their airfields was known. After the occupation of Czechoslovakia, it was found that the Czechoslovakia cypher bureau had solved a Wehrmacht code called Kammsschlüssel, and was reading it easily. Consequently, followed a greater limitation of the use of Wehrmacht low-grade codes.
In Romania, air force traffic and the police networks were monitored. The police code was solved, but the reports contained therein were of no interest. Monitoring of Romania ceased in spring 1941 and was not resumed until the Royal coup occurred that transferred the loyalty of the country to the Allies in 1944.
The monitoring of Turkey was considered a success. Strength and deployment of its air forces were known and its codes read. Turkish RT traffic was also intercepted.
Special attention was paid to the Soviet Union and very early the results of this monitoring gave valuable information to the signals intelligence and pilots of the Luftflotte 4. When the war started, signals on the southern sector was prepared.
Operations
Poland and Balkans
At the beginning of the campaign, the mission of the battalion was to monitor the Soviet Air Force in the area of Luftflotte 4. The following signals units were used:
The battalion also had operational control of the signal companies of the Fliegerkorps. The request of Luftwaffe signals intelligence to incorporate those Fliegerkorps companies into the signals battalions was met by the strongest resistance on the part of the Fliegerkorps and did not materialise on the southern sector, until the end of 1944. The fact that the signals intelligence had operational control of the Fliegerkorps signal companies, but was not aware of their movements when the Fliegerkorps unit moved, caused considerable difficulties.
At the beginning of the war, the battalion had 90 WT receivers in operation, which were considered sufficient. The geographical dispersion of the companies of the battalion made centralised control very difficult. For this reason, all mobile companies of the battalion were concentrated in Nikolayev in September 1941 and remained with Luftflotte 4, and from there, in turn in the same year to Kislovodsk. Owing to the impracticability of administering the companies located near Rzeszów and Constanța due to the distance involved, they were transferred to the Chi-Stelle battalion. During the German retreat, the battalion moved back to Mariupol in January 1943; a month later it moved to Kryvyi Rih, and in April 1943 to Kamianske to ensure better communication with the Luftflotte. By autumn 1943, it was moved back to Nikolayev.
The signals battalion of Luftflotte Don that had been activated in autumn 1942 was dissolved in December 1943. One of its companies was temporarily attached to the signals battalion of Luftflotte 4. By February 1944, the battalion had reached Odessa, but Allied attacks required a further move to Bacău. Communication difficulties prompted another move from Hungary to Debrecen, Turkey in April 1944. Two signal companies of the Fliegerkorps and the old company in Constanța were returned to the battalion in the summer of 1944. Frequent air attacks forced the battalion to retreat to Horn, Austria. One company was left with the Luftflotte. This was done to assure immediate intelligence to the Luftflotte so that it could undertake prompt countermeasures as required. Had the company moved with the battalion, this service would not have been available in the timely manner required, as communication over long distances was difficult and frequently disrupted. At the end of April the battalion moved to Münzkirchen. The last move was to Tauplitz on 4 May 1945, where operations ceased at 1200 hours on 8 May 1945.
Operational details

Introduction

Within the Luftwaffe Chi-Stelle, the principles and procedures underlying traffic evaluation did not differ materially as between the West, South and East. There was no difference in operational principles between West, South and East Luftwaffe signals agencies.

Personnel

The following types of specialist personnel were employed by the signal battalions on the Eastern front.
Statistical material contained in a card index file was a critical aid to evaluation. This file contained all the information known of Soviet forces and included the number of their units, and their organisation, their record in the war to date, the location of airfields and other salient details, and names of important personalities. Naturally, these records were guarded very carefully and safely stored during bombing or other perilous situations.
Soviet grid systems
All messages in which names of localities were given in grid reference were handled by a grid specialist.
Soviet grid references were usually expressed by a 6-figure group with a letter frequently added. The reference was often used to inform Soviet air units of the bomb line. Since the operational sectors of the individual Soviet units were known, and since the Soviet and German front lines were both the same, an entry into the grid system was easily accomplished. The breaking of the map code was further facilitated by the fact that the Soviets in order to specify a location exactly, often put the first, or the first and last name at the end of the figure group e.g. Mykolaiv 412312N, Tarnov 52394Tv. Another point of entry into breaking these grid references was that in the case of a string of encoded locations a reference to terrain elevation was usually left unencoded.
The two most prevalent grid systems were:
The first system was used by the Soviet Air Raid Warning Service, and by the long-range bombers, while the second was used by the tactical aviation units, and had many variations.
The following is an example of the Air Raid Warning System; the entire map was divided into large, small and smaller squares. A large square consisting of 1 degree of longitude and 0.5 degrees of latitude. Longitude and latitude references were expressed in a code, which usually changed monthly. A large square was divided into nine small squares, while they, in turn, were subdivided into four smallest squares. A single digit was used to designate the small and smallest squares. These numbers for the squares remained constant and ran clockwise, beginning in the upper left-hand corner. Longitude and latitude references of the large square expressed by the coordinated of its upper and left- hand corner. Thus as shown in , the encoded references for the city of Poltava would be 465262.
The Gauss-Krüger system was a design for a much smaller grid, the primary difference being that the dimensions of the largest squares were selected arbitrarily by the individual units using the system. From the Chi-Stelle standpoint, the size of these squares could be determined only through experience. The system of numbering the small and smallest squares was the same.
The method of encoding the coordinates used to designate a large square varied with each Soviet air army, and often with units within the air army. Further difficulties for the agency were exposed by the fact that the coded equivalents for longitude and latitude did not always run regularly from west to east and north to south, but occasionally in the opposite order; also some units might choose to use all even numbers, while other units chose odd numbers.
In some systems the large squares were not encoded by number, but with a code name, e.g. lipa for Linden tree, and the encoded reference would not read as 425391 but lipa 91.
In another grid system, longitude was expressed by a double 2-digit number and latitude by three. The next reference referred to the smallest square, the small square being omitted, thus, this system still resulted in a 6-digit reference. This grid was used only in conjunction with large-scale maps.
Prearranged form messages
Soviet pre-arranged form messages were handled by an individual specialist belonging to the evaluation company. Some messages had the characteristics, in which they differed from other types of traffic:
The following is an example of a typical prearranged form message.
Daily reports of this type indicating stocks of rations, ammunition and fuel, the condition of airfields, changes in personnel strength, were made by subordinate units to the senior HQ's.
Prearranged form messages of combat aviation units contained, for the most part, details as to strength, location, operational status of aircraft and crews and seldom gave any information as to operations, duration of flights or losses. Any grid locations mentioned in such messages were encoded. The following is an example of such a message:
In addition to their valuable contents, these messages were an important aid to the identification of call signs and networks. Even when call signs were changed daily, a Soviet unit was easily identified through this information as to members of aircraft and crews, and quantities of oil, fuel, ammunition, which were given in the clear. Since the form of these messages usually remained constant for seven to fourteen days, it was necessary to refer to a similar message of the previous day in order to recognise the unit, and therewith to re-identify the call sign.
Daily summaries and operations reports of combat aviation units were also reported by pre-arranged form messages. Numbers in these messages were encoded, but in such a simple form, however, that speedy analysis was possible. The digits 0 to 9 were enciphered by 3-digit numbers from a prescribed group of 100 numbers. For example, 812=1, 816=2, 831=3,854=4 and so on. The various types of aircraft were encoded with other 3-digit numbers from another group of 100 numbers. For example, LA=507, IL-2=513, IL-4=514, A-20=515, Liberator=524, JU=532. Designations of types of units, e.g. fighter aircraft, fighter-bomber, were encoded within another one hundred number group. The code numbers were changed frequently, but the order of meanings within each hundred member groups remained constant. It was therefore usually sufficient to identify one meaning only in order to re-establish the whole sequence of meanings within a hundred number group.
This system was also used by Soviet long-range bomber groups in their strength reports, and by the Soviet Air Raid Warning Service. It was valid for the whole of the eastern front, and therefore of the greatest importance to all the Chi-Stelle battalions which competed with each other in an attempt to be the first to break a new addition of this code.
Weather messages
Encoded weather messages were given directly to the weather liaison officer. These could be easily identified by their indicator, by the random use of the letter X within the text of the message, and by the absence of message numbers and delivery groups. Weather messages, sent in clear text, were quite frequent at the beginning of the war but became rarer later on. These were translated into German before they were forwarded to the liaison officer.
The weather liaison officer deciphered messages by means of a deciphering table which was broadcast every six hours from the office of the Chief of the Luftwaffe Weather Service. Weather messages were of assistance in identifying the geographical origin of other traffic intercepted on the same networks, as the weather intercepts often mentioned meteorological stations together with their locations.

TICOM