The wireless signal propagation characteristics from a satellite based transmitter to an airborne receiver are of special interest for air traffic management as well as for passenger communications. Especially applications incorporating safety-of-life features require not only an average reliability of the transmission link but rather a high availability and have stringent requirements on the continuity-of-service. In order to test and validate new developed receiver algorithms, software based implementations are used which allow a faster time to market. Therefore, channel models designed to simulate propagation characteristics of the satellite-to-aircraft channel need to address all aspects of propagation impairments.
In the Aeronautical Satellite Communications Channel Characteristics project propagation measurements for the satellite-to-aircraft and satellite-to-helicopter case have been performed using GPS signals as signals of opportunity for channel sounding. Overall eight different measurement flights with four different aircraft have been performed. The flight measurements were performed in Austria over different types of terrain like water, forest or glaciers. Measurements were performed using devices owned by or developed in the Institute of Communications and Navigation. As a result a propagation channel model for the satellite-to-aircraft case for L-band was developed by the institute based on measured flight data. Comparisons between ground surface reflections for L- and K-band were performed showing that existing L-band propagation models might be extended to higher frequencies. Out of the project, several conference publications were published where one was awarded for the best paper in propagation at the European Conference on Antennas and Propagation.
European Space Agency (ESA)
University of Vigo