AAS 98-199

GPS ATTITUDE DETERMINATION BY KALMAN FILTERING: SIMULATION OF MULTIPATH REJECTION

F. Bernelli-Zazzera - Politecnico di Milano, Italy; R. Campana, F. Gottifredi, L. Marradi - LABEN S.p.A., Italy

Abstract

This paper presents the results of the design of a high accuracy attitude determination solution, based on the design of a Kalman filter attitude solution using differential phase measurements. The Kalman filter designed includes as system states the quaternions and the angular velocities. Results show that the filtering process is able to significantly reduce the effects of measurements noise and also the effects of colored noise (multipath) when aided with an accurate model of the spacecraft dynamics and of the main angular perturbations. Numerical results indicate that the error in the attitude estimate, expressed in terms of Euler angles referred to an orbiting frame, are dependent on the multipath effects. In the case of a "good" geometry, i.e. low multipath, the standard deviation of the attitude error is in the order of 0.1 degrees, while with a high level of multipath it is in the order of 1 to 2 degrees, depending on the particular situation simulated.

Back