Simulation of the Longitude Error due to Signal Propagation in a Passive Emitter Tracking Geolocation Algorithm

The aim of this study is the simulation of the contribution of the position error due to signal propagation in a geolocation algorithm, which is the estimation of the position of a target in geographic coordinates. The analysis considers an emitter placed on the surface of the Earth and a passive receiver mounted on a satellite in LEO (Low Earth Orbit) which is able to perform AoA (Angle of Arrival) measurements. The adopted approach involves the analysis of the origin of the position errors through the study of the relative geometry between the satellite and the target, considering both their relative movements and the time delay in a single AoA measurement. The focus is on the longitude component of the position error and its numerical simulation and a strategy of error compensation is derived. Two alternative algorithms of simulation are also presented and simulated. Finally, the fitting of simulated data in form of first degree and second degree polynomial models are presented and discussed.