German Intercept Station Operations were intercept operations that were undertaken by the German Army forces in Europe during World War II. Interception is the gathering of radio signals as part of a signals intelligence operation. It was a major part of German radio intelligence operations during World War II.

History of intercept operations during the interwar period Station operations 1915-1923 The Imperial German Army began its development of a signal intelligence organisation during World War I under the direction of Colonel Walter Nicolai. In 1906, Nicolai began his career in Abteilung IIIb, when he took over the intercept station at the Königsberg fortress in KönigsbergHeinz Höhne: Canaris – Patriot im Zwielicht. S. 150f. to mainly spy on the Russians. He was commanding officer of military intelligence unit, Abteilung III b from 1913 to 1919.Heinz Höhne: Canaris – Patriot im Zwielicht. S. 150. However it was not until 1915 that the army realised a nascent intercept organisation through the dedicated work of Nicolai. Nicolai developed the basic structure of the armies intelligence system, by creating a system of companies that monitored either short or long range wireless signals. The intercept companies were attached to the army at division level. These companies were known as fixed intercept network stations () (Feste) and became operational in 1923.

Station operations 1923–1933 Assignment of intercept coverage from 1923 to 1933 was made by the Code and Ciphers of the Defense Ministry (). The division of intercept tasks was established on a geographical basis. The Munich outstation intercepted traffic from Italy, which included the Italian colonies, Yugoslavia, Romania, Hungary, Austria, and Czechoslovakia. The Stuttgart outstation monitored France, including her colonies, Belgium, the Netherlands and Spain. Münster intercept outstation monitored England including colonies and Dominions. The intercept station at Königsberg intercepted Russian traffic. The Breslau intercept station monitored communications traffic from Polish, Czechoslovak and Russia. The Liegnitz had twice the personnel of the stations.

The personnel of each intercept station consisted of one officer, who was Chief of the station, one radio mechanic, eighteen or twenty non-commissioned officers and six or eight civilian employees used as clerks, administrators, interpreters and couriers. In 1933, five technicians were added to the personnel. Not until 1932 did the Fixed Intercept Stations (German:Feste Horchstelle) (Feste) receive their tables of organisation. Only the finest and most experienced radio operators of the signal battalions and platoons were accepted as intercept operators. The chief of an intercept station, by having the direct support of the Reichswehr Ministry, was certain always to receive the best qualified personnel.

The material intercepted daily was studied by the traffic analysis section, bearings obtained on the stations involved and the results incorporated into a daily traffic analysis report, which was called N.B. – Meldung. All Wireless telegraphy (W/T) intercept messages, where the keys were known was done directly at the intercept stations. The contents of the decoded messages were then evaluated. All W/T messages which could not be decoded by the intercept stations (e.g. all diplomatic messages) were sent daily to the Chi-Stelle in Berlin, where they were worked on by a larger and more specialised cryptanalytic staff of the Reichswehr. The Chi-Stelle in Berlin was divided into various sections, each headed by a section leader. The sections or desk each dealt with an individual country. In one instance, when the manoeuvrers of one of the large foreign powers were being monitored, the head of the desk dealing with the country in question was sent to the appropriate intercept station for the duration of the manoeuvres.

The first real military activity that the Munich intercept unit undertook was the monitoring of the Rif War that was fought between 1920 and 1926. The deployment and operational tactics of the Spanish and French were learned in details through the decoding of wireless messages, with the Weimar Republic supplied with regular intelligence reports.

Station operations 1933–1939 In 1933, the OKH assumed general control of the intercept organisation and the Intercept Control Station (HLS), directed intercept coverage. A program of expansion and improvement was instituted, with the creation of three new fixed intercept stations at Striegau, Hersbruck and Chemnitz.I-185 p.3 All intercept stations were improved. By 1934, for instance, each had its own building outside city limits where it was free from electrical interference and each was equipped with the latest technical improvements. In 1935, the first mobile Signal Intelligence Companies were activated, and populated from Signals Corps recruits. Officers, NCO's and privates from the fixed intercept stations acted as instructors In selecting this new military personnel, no consideration was given to an individual's background; the only requirement was a certain degree of intelligence. Many difficulties resulted, which had repercussions through the entire German Signal Corps. This policy continued for an excessively long time, around two years, in order to bring the companies up to strength. The lack of technically trained personnel, especially amongst the officers remained one of the greatest deficiencies of the German Signals Intelligence units, right up until the end of the war.

At that time, the Army was intercepting all Army, diplomatic and Air Force traffic. The Army traffic was sent for analysis to the Army cryptoanalytic and evaluation agency, the Intercept Control Station (HLS) at Berlin. Diplomatic traffic was passed either to the Codes and Ciphers Office of the Reichswehr before 1935 and later the same office at the Wehrmacht, or the Pers Z S.I-85 p.2 Technical Sergeant Karl Jering of the Signals Corps of the Air Force High Command, (Order of Battle OKL/LN Abt. 350) noted during his tour of duty, that during this period, the Army intercepted and evaluated foreign Air Force traffic, but he observed time and time again that far less importance was given to the monitoring and evaluation of Air Force traffic, than it gave to ground force traffic. The Air Force was becoming increasingly dissatisfied with the Army intercept work and in 1935, began to organise its own Signals Intelligence Service. For three years however, between 1935 and 1938, the Air Force maintained close relations with the Army. Air Force employees underwent familiarization training at Army Fixed Intercept Stations and the Air Force radio intercept stations, (), (W-Stellen) were created according to the Army prototypes By 1939, the break between the Signals Intelligence Service of the Army High Command, and of the Air Force High Command was complete.

At this time the Supreme Command of the Armed Forces, the Oberkommando der Wehrmacht (Abbr. OKW), also created its own intercept service for diplomatic traffic. The Army gave to the OKW two of its intercept stations, Lauf and Treuenbrietzen for the interception of this traffic.I-85 p.3 From this period on, the Army intercept service confined itself exclusively to the interception of foreign Army traffic.

Intercept operations during World War II Intercept station operations 1939–1944 Before 1939, the German General Staff has placed very little emphasis upon intercept in the field. Nearly all intercept has been carried out by Fixed Intercept Stations. With the approach of mobile warfare, however, Germany Army intercept operations also became mobile. The new emphasis on field intercept resulted in the establishment of Signal Intelligence Regiments () (KONA) whose mobile component parts were designed to work with units of the Army Group to Army Corps level). The adaption of the KONA regiments to meet the needs of the Field Army was one of the chief accomplishments of the Army signal intelligence service.

Control of intercept coverage 1939–1944

Control of intercept coverage during the war stemmed from the Intelligence Officers of the Eastern Armies Branch and the Western Armies BranchI-86, p. 2 As Alfred Jodl stated:

these officers were thoroughly familiar with the general signal intelligence picture

The chain of command was very clear during the last year of the war. The Intelligence officers of the Eastern Armies Branch and the Western Armies Branch briefed the chief of the Understaff of General der Nachrichtenaufklärung (GdNA), who had control over all the KONA regiments and who issued to them their directives for intercept coverage. In the west, the Understaff worked through the Senior Commander of Signal Intelligence, () (Abbr. Hoeh Kdr d. NA) whose function it was to coordinate the intercept coverage of KONA 5 and KONA 6.

With the other KONA, the chain of command from the Understaff was direct. The Signal Intelligence Evaluation Centre (NAAS) issued the directives for intercept coverage to all units subordinate to the KONA.

In 1941 to 1944, previous to the establishment of the GdNA organisation, the chain of command appears to have been the following: Non-Russian intercept coverage was distributed by the Western Armies Branch through the Control Station of the Signal Intelligence of the Army High Command (OKH/LNA) Russian intercept was directed by the Eastern Armies Branch through the Intercept Control Station East of the Army High Command (OKH/HLS Ost)

Assignment of intercept coverage Assignment of intercept operations was established on a geographical basis; either eastern, south-eastern, western, southwestern. From the beginning of the war eastern, interception was given high priority and KONA 1,2,3 were assigned to eastern coverage. In 1942, KONA 6 and in 1944 and 1945, two other KONAs, KONA 8 and KONA Nord were formed also for the interception of eastern traffic. In addition, eastern interception was carried on by three independent Stationary Intercept Companies, Feste 7, Feste 8, 11 and one Long Range Signal Intelligence Platoon, Faz Nord. After 1942, new monitoring of eastern traffic was also done by the Intercept Control Station East (HLS Ost) In contrast, southeastern, western and southwestern interception were covered by one KONA regiment apiece, with one central monitoring agency for all three areas, the Control Station for Signal Intelligence (LNA).

Eastern intercept

The mission of all eastern KONA regiments was the interception and evaluation of Russian Army, Air Force and Partisan traffic. Their intercept coverage differed only in respect to the geographical origin of the traffic. KONA 1, which was during the 1939–1944, attached to Army Group South Ukraine () covered the southern part of the Russian front. It operated in the vicinity of Lemberg, Vinnytsia, Poltava, Reichshof, and Nový Jičín. KONA 2 which was attached to Army Group Centre covered traffic on the central Russian front, moved in the vicinity of Warsaw, Borisov, Orsha, Vitebsk, Smolensk, Minsk, Grodno. KONA 3 which was attached to Army Group North, covered traffic on the northern part of the Russian front and in the Baltic states. It was variously at Riga/Dueneberg, Pskov and Courland, where in 1945 it was caught in a pocket by the Russians and captured intact. KONA 6 was formed in 1942 to cover the traffic of the Battle of the CaucasusDF-18, p.81 While in the east, the unit was located at Rostov-on-Don, Novocherkassy and Minsk. After that campaign, it was assigned to the interception of Russian Partisan traffic, and kept this as its intercept coverage until 1944, when it was withdrawn from the east and reassigned to the Western Front.