page_title: Luftnachrichten Abteilung 350
section_title: Soviet grid systems
hierarchical_section_title: Luftnachrichten Abteilung 350 / History of operations in the east / Technical operations in the east / Analysis and evaluation of special traffic / Soviet grid systems
caption_attribution_description: The grid system used by the Soviet Union during World War 2.
context_page_description: 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.
context_section_description: 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:
  Enciphered longitudinal and latitudinal references, used in connection with small-scale maps and valid for the entire Eastern Front.
  The Gauss–Krüger coordinate system in connection with large-scale maps, used only on certain sectors of the front.
  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 [Figure no 1], 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.
caption: Soviet Grid System during World War II
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