Spacecraft Formation Orbit Estimation Using WLPS-Based Localization

Shu Ting Goh,Seyed A (Reza) Zekavat,Ossama Abdelkhalik

doi:10.1155/2011/654057

Abstract

This paper studies the implementation of a novel wireless local positioning system (WLPS) for spacecraft formation flying to maintain high-performance spacecraft relative and absolute position estimation. A WLPS equipped with antenna arrays allows each spacecraft to measure the relative range and coordinate angle(s) of other spacecraft located in its coverage area. The dynamic base station and the transponder of WLPS enable spacecraft to localize each other in the formation. Because the signal travels roundtrip in WLPS, and due to the high spacecraft velocities, the signal transmission time delay reduces the localization performance. This work studies spacecraft formation positions estimation performance assuming that only WLPS is available onboard. The feasibility of estimating the spacecraft absolute position using only one-dimensional antenna array is also investigated. The effect of including GPS measurements in addition to WLPS is studied and compared to a GPS standalone system.

Highlights

The relative and absolute positions estimation of spacecraft formations is a fundamental task in many space missions
Relative position estimation plays an important role in spacecraft formation flying (SFF) missions, a subject that has received a great deal of attention by researchers in recent decades
The performance is assessed through computing the average of the root mean square error (RMSE), η, of the estimated absolute positions of all spacecraft in the formation

Summary

Introduction

The relative and absolute positions estimation of spacecraft formations is a fundamental task in many space missions. When an observing spacecraft transmits a signal to a target spacecraft, the signal transmission time delay causes errors in the measured relative position [17, 18]. The orbits of two or more spacecraft in a formation are estimated through the implementation of a wireless local positioning system (WLPS) that enables relative localization [23]. The DBS installed on one spacecraft measures the relative position of the TRX installed on another spacecraft, which is located in its coverage area via time-of-arrival (TOA) and direction-of-arrival (DOA) estimation. (2) The absolute position estimation of spacecraft in formation using 2D WLPS, taking into consideration the signal time delay. The position information across multiple spacecraft can be fused to improve the localization performance [27]

System Model

Extended Kalman Filter Implementation

Simulation Results and Discussions

Conclusion