Influence of Attitude Errors on Angle-of-Arrival Receivers in Satellite Systems

Abstract

The context is satellite systems with an antenna array payload. The satellite has to geolocate an emitter of electromagnetic waves placed on the surface of the Earth. The sensing technique is angle of arrival (AOA). The objective of the paper is to model, simulate, and quantify the influence of errors in the attitude determination and control system (ADCS) on payload performance in the case of nadir pointing. The prediction and evaluation of these performances are of interest for a new set of technological demonstrators and next-generation systems for search and rescue applications and spectrum monitoring of jamming signals. Through the building and analysis of the mathematical model, the identification of two effects is performed: a direct effect on the value of the measurement and an indirect effect on its dispersion. The methodology involves Monte Carlo simulations varying the relative configuration between the terrestrial emitter and the satellite in terms of orbital parameters. The results include the main trends and the full statistical characterization of the distribution of the errors for azimuth and elevation angles and Cramér–Rao lower bound. Insights on emerging cases of divergence of measurement for configurations of alignments are also presented and discussed.