Naval radio direction-finding

High-frequency direction finding

“…As instrumental errors were reduced, the importance of errors arising from site imperfections and wave interference effects became greater, and interest grew in systems working on a larger portion of the arriving wavefront, e.g. two or more Adcocks combined in group working 14 and, in Germany, on the Wullenweber system. 15 Research in the immediate post-War years, particularly at the Radio Research Station, was increasingly devoted to the study of wavefront behaviour and of the value of space averaging compared with time averaging.…”

“…14 Since the War, systems of the Wullenweber type have been developed in a number of ways. Much of the work is classified, but it can be stated that losses in the goniometer have been greatly reduced and the mechanical precision of this vital component improved.…”

Performance Characteristics of a Spaced Loop Antenna Formed by Two Arbitrarily Oriented Parallel Loops

“…By analogy to A, F is given by F m dT (9) For the dipole at Pk of Figure Z, equation (9) Reference to Figure 2 shows the dipole is located a distance rk from the point of observation where rk is given exactly by rZ = r 2 + rd 2 -Zrrd cOs If (15) where cos -= sine sin kcos(kt -00k) + cos 0 cOs Ok A binomial expansion of (15) yields…”

Shore High-Frequency Direction-Finding in the Battle of the Atlantic: An Undervalued Intelligence Asset

“…Both the aural and the cathode ray sets used four fixed Adcock "U" type vertical aerials about 10m high and 6m apart, with buried connections. Adcock aerials are superior37 to Bellini-Tosi crossed loops for shore use, since they greatly reduce polarity errors (which arise when an aerial system cannot distinguish between the vertically and horizontally polarised components of a signal). Polarity errors were also reduced on sites with poor conductivity, by installing extensive earth mats 38.…”

“…The Kriegsmarine believed that, when combined with off-frequencies, Kurier signals could not be fixed. In fact, the Plessey visual sets were refined to fix Kurier signals, but141 only if the frequency was known, which would not necessarily have been the position. Spurt transmission was undoubtedly a most important development, which haunted NATO during the Cold War, but it came too late to help the 142 U-boats.…”