Autonomous formation keeping of geostationary satellites with regional navigation satellites and dynamics

Abstract

In this paper, the reduced dynamic autonomous formation control of geostationary-Earth-orbit satellites using Indian Regional Navigation Satellite System observables is presented. Generally, the navigation signal is used to determine the position, velocity, and time kinematically. The kinematic formulation, however, is geometric and vulnerable to data outage and cycle slip. Weak geometry of navigation satellites causes high dilution of precision. In this situation, dynamics can provide the estimates with little degradation in accuracy. This requires combining Indian Regional Navigation Satellite System observables with orbital dynamics of the geostationary-Earth-orbit satellites in an extended Kalman filter setup, resulting in improved position and velocity estimates. Moreover, solar radiation pressure coefficient, ephemeris error, and any other unaccounted minute forces are estimated through an empirical acceleration model, along with receiver clock bias and drift, in a reduced dynamics formulation. Furthermore, it is demonstrated that these position and velocity estimates permit autonomous station and formation keeping of geostationary-Earth-orbit satellites. The classical technique using the sun and moon and solar radiation perturbing accelerations to advantage is used to control eccentricity and inclination vectors of each satellite in the formation. The formation-keeping control maneuvers are performed autonomously, whenever an individual satellite's eccentricity or inclination limit is exceeded. © 2016 by Aaron Estes and Manoranjan Majji.