| 摘要 |
Tactical Radio Navigation systems provide distance measuring information to an interrogating aircraft in response to pairs of interrogation pulses received at a beacon transponder, the system also provides bearing and identification information. A single antenna functions to both receive the interrogation pulses and radiate the position determining signals in a radiation pattern having a single fundamental lobe and nine harmonic lobes superimposed thereon with a complete pattern being rotated at a constant speed. In such a system, it is necessary to know when the rotating radiated pattern is pointing 90 DEG clockwise from magnetic north so that a reference pulse may be transmitted to orient the pattern to an interrogating aircraft. Radio navigation systems at fixed sites are oriented on installation to provide accurate indexing information as to the radiated pattern. Systems mounted on a moving platform, however, wherein the antenna does not maintain a fixed orientation, require additional indexing information to properly orient the radiation pattern to an interrogating aircraft. This additional processing of reference pulse information is provided by time incrementing the moving platforms heading reference for a period calculated to orient the radiation pattern with reference to magnetic north. The incrementing time is determined by comparing the incremented heading reference with a signal related to magnetic north.
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