Relative state estimation and observability for formation flying satellites in the presence of sensor noise

This paper presents an investigation into the relative state estimation and observability for two formation flying satellites using two different relative navigation sensor sets. The first set consists out of a transmitter antenna on one satellite and a single receiver antenna on the other satellite to measure the inter-satellite range using a radiofrequency ranging signal. The second set uses three receiver antennas to measure multiple ranges, effectively providing angular information. It is derived in the paper that for the more complete sensor set, the error in the estimation of the relative state is a function of the pseudorange error, the inter-satellite distance, and the receiver antenna baselines. By varying these variables, conditions are found for which the observations obtained using the first sensor set result in relative state estimation and observability comparable to those obtained with the more complete sensor set. This offers potential reductions in cost and complexity for certain mission scenarios.Space EngineeringAerospace Engineerin