Aeronautical GNSS Channel Model for Spurious Signals Arriving from Below the Horizon

This article presents models and results for simulating the aeronautical GNSS channel when a spurious signal is arriving from below the horizon. The proposed models concern the source, the multipath channel and the airborne receiver antenna. For this latter, two solutions are proposed: a simple one with constant below-the-horizon characteristics, and a more realistic that uses a far-field simulation in the presence of the airframe structure. Simulation results on a comprehensive test-case are discussed.