Relative Navigation in LEO by Carrier-Phase Differential GPS with Intersatellite Ranging Augmentation

Abstract

Carrier-phase differential GPS (CDGPS) is a promising technology for accurate relative navigation in LEO formations of cooperating satellites, but navigation filter robustness against poor GPS geometry and noisy measurements has to be improved. This can be performed by augmenting the navigation filter with intersatellite local ranging measurements, as the ones provided by ranging transponders or GNSS-like systems. In this paper, an augmented CDGPS navigation filter is proposed for the formation of two satellites characterized by a short, varying baseline, relevant to next generation Synthetic Aperture Radar missions. Specifically, a cascade-combination of dynamic and kinematic filters which processes double-differenced code and carrier measurements on two frequencies, as well as local inter-satellite ranging measurements, is used to get centimeter-level baseline estimates. The augmented filter is validated by numerical simulations of the formation orbital path. Results demonstrate that the proposed approach is effective in preserving the centimeter-level accuracy achievable by a CDGPS-only filter also in the presence of a poor GDOP or a limited number of GPS satellites in view.

Adaptive Coding in Control of Two Satellites Relative Motion Over the Packet Erasure Communication Channel

“…Control signals for each satellite are generated so as to provide the difference u = u2 − u1, generated in accordance with the chosen control law u = U (x12, z12, x˙12, z˙12). It is supposed that each satellite can transfer position information to another one received by onboard navigation equipment, for example, using GLONASS / GPS receivers, installed on each [38] satellite and share this information via the digital inter-satellite communication channel.…”

Precise Orbit Determination of BDS MEO Satellites Based on Satellite TT&C Stations

“…(1) All BDS GEO/IGSO satellites can be observed, commanded, and controlled because they are within the range of the ground TT&C (GTT&C) stations or differential stations of the Chinese's own. (2) On the basis of the precise orbital determination of BDS GEO/IGSO satellites, referring to the relative navigation way in Low Earth Orbiting (LEO) by using carrier phase differential GPS [13], we can install the receivers on BDS MEO satellites, which can receive the signal from BDS GEO/IGSO satellites by using omnidirectional antenna. Thus we consider BDS GEO/IGSO satellites as STT&C stations and can use the method of multifrequency combination technology to realize the precise orbit determination of BDS MEO satellites ulteriorly.…”

Navigation Facility for High Accuracy Offline Trajectory and Attitude Estimation in Airborne Applications

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