ARS Advances in Radio Science ARS Adv. Radio Sci. 1684-9973 Copernicus Publications Göttingen, Germany 10.5194/ars-5-49-2007 Airborne field strength monitoring Bredemeyer J. 1 Kleine-Ostmann T. 2 Schrader T. 2 Münter K. 2 Ritter J. 3 FCS Flight Calibration Services GmbH, Braunschweig, Germany Physikalisch-Technische Bundesanstalt, Braunschweig, Germany EADS Deutschland GmbH, Military Aircraft, Bremen, Germany 12 06 2007 5 49 55 Copyright: © 2007 J. Bredemeyer et al. 2007 This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/ This article is available from https://ars.copernicus.org/articles/5/49/2007/ars-5-49-2007.html The full text article is available as a PDF file from https://ars.copernicus.org/articles/5/49/2007/ars-5-49-2007.pdf

In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 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 of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

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