I am indebted to author Martin Streetly for the suggestion (supported by Michaël Svejgaard) that WIM was a contraction of »Windmeß-Stelle« (= wind measurement station) and thus a cover name ralong the lines of the RAF’s use of “Air Ministry Experimental Station” for its radar sites.
WIM stations were situated around the Axis-held coasts of the Mediterranean, typically on high ground from which Axis shipping routes could be covered. Their role was to monitor and disrupt Allied radars and ground-to-air communications. Some were devoted to the protection of convoys from search aircraft, others provided screening for Luftwaffe and Regia Aeronautica raids on Malta and the Nile Delta. (I have yet to find out whether WIM was an acronym or a cover name — Wim is short for Wilhelm for example). Some if not all were co-located with navigation beacons. Gosewisch again:
For our own direction finding, heavy long-wave radio beacons with 1 kW transmitters were positioned on the eastern and western tips of Crete … To increase their range [they] had to be erected on the highest possible points in the terrain.
Kounavi, Crete was known to the crew of 6N+AJ (see above) as Sultan 3, it was “the main intercept station” but it also supplied weather reports and other information to Fliegerkorps X’s bombers. The site was operated by 9. (Funkhorch)/Luftnachrichtenregiment 40, charged with monitoring Allied signals traffic. While that regiment’s 7. (Aircraft Reporting) Coy. had been in Crete as early as July 1941, an advance party from the 9. only arrived on 30 March 1942, with the main body en route on 9 April (another platoon was in Africa a week earlier). This suggests that development of the island’s WIM stations may have begun that Spring.
Overall control of Luftwaffe signals in the Mediterranean Theatre rested with Oberst Heinrich Aschenbrenner (Nachrichtenführer, Luftflotte 2) but there is evidence of continuing interchanges with Luftwaffe research establishments, and the postal service main office (Reichpostzentralamt or RPZ) whose laboratories in Potsdam developed much of the equipment used in the WIM stations. The monitoring and jamming effort was co-ordinated by the WIM-Zentrale at Kounavi, Crete, in the sphere of X. Fliegerkorps.
Oberst Walter Gosewisch was Chief of Signals with X. Fliegerkorps from November 1941 until July 1942:
… In the summer of 1942 the Funkmeßbeobachtungs- und Störkompanie z.b.V. [special-purpose radar monitoring and jamming company] was still being built up, with regard both to personnel and equipment. It monitored British radars on the African coast and the radar (ASV) aboard their reconnaissance aircraft. The results were satisfactory. The jamming transmitters were not yet fully up to the job and probably without any lasting effect on the enemy radar sets. The radar search and jamming service in the Eastern Mediterranean area never reached full development. By this time the focal point of the high frequency war was around Malta.
Parts of the network had been established or were under construction by April 1942. It seems that the first »Nachtfalter« operation had been intended for early June but was postponed for about a week after Dr. Scholz’s arrival in the Mediterranean was delayed “for urgent reasons”. Once he arrived, Scholz was to confer with Ob. Süd before the action could proceed, suggesting there was high-level interest in the timing of the operation, perhaps to coincide with some other Axis enterprise. What was more, further equipment which had been ordered was still under construction. Aschenbrenner told RPZ Sonderkommando Antonius (“Antonius” was the cover name of Ob. Süd) that their gear was not to be dismounted from “the vehicle”—implying that the installation was mobile—but Sonderführer Mahlow was to proceed at once to Berlin with a full report and Wolf (a colleague?) was to take over the functioning of the WIM. The RPZ personnel were also to return right away, with the exception of a driver to look after the vehicle and a man to take responsibility for the equipment.
Each Mediterranean WIM station had a number, apparently reflecting the order in which they were established. Those I have identified are: