Airborne field strength monitoring

[摘要] In civil and military aviation, ground based navigation aids(NAVAIDS) are still crucial for flight guidance even though theacceptance of satellite based systems (GNSS) increases. Part ofthe calibration process for NAVAIDS (ILS, DME, VOR) is to performa flight inspection according to specified methods as stated in adocument (DOC8071, 2000) by the International Civil AviationOrganization (ICAO). One major task is to determine the coverage,or, in other words, the true signal-in-space field strength of aground transmitter. This has always been a challenge to flightinspection up to now, since, especially in the L-band (DME, 1GHz),the antenna installed performance was known with an uncertainty of10 dB or even more. In order to meet ICAO's required accuracy of±3 dB it is necessary to have a precise 3-D antenna factor ofthe receiving antenna operating on the airborne platform includingall losses and impedance mismatching. Introducing precise,effective antenna factors to flight inspection to achieve therequired accuracy is new and not published in relevant papers yet.The authors try to establish a new balanced procedure betweensimulation and validation by airborne and ground measurements.This involves the interpretation of measured scattering parametersgained both on the ground and airborne in comparison withnumerical results obtained by the multilevel fast multipolealgorithm (MLFMA) accelerated method of moments (MoM) using acomplex geometric model of the aircraft. First results will bepresented in this paper.

[学科分类] 电子、光学、磁材料