A Parametric Study of Relative Navigation Using Pulsars

A.A. Emadzadeh, J.L. Speyer, and F.Y. Hadaegh

Abstract:	In this paper we formulate a simplified version of the relative navigation problem between two spacecrafts which can be used for accurate determination of the relative position estimation when integrated with an IMU. We formulate the dynamics of relative position between two spacecraft that include a simple model of the IMU accuracy. The measurements, which are basically obtained by time tagging the photons and fitting the pulsar profile to the photon dispersion, are modeled as a linear function of the projected relative position onto the unit direction to the pulsar plus measurement noise. The measurement noise variance is selected on an estimate of how well the pulsar profile is fitted to the photon dispersion. Then, by applying a Kalman filter, we estimate the relative po- sition and obtain the steady state estimation error covariance. We investigate the effect of the different system parameters on the achievable accuracy in relative position estimation. In particular, we have considered the effect of different values of IMU uncertainty, measurement noise variance, the sampling rate on the IMU and pulsar measurements, number of pulsars used for estimation and their geometric dis- persion in the Galactic disc. We generate the steady state covariance of the position estimation error for different values of these parameters. We have shown that under current capability we can achieve relative position estimates in a reasonable time (24 hours) with an rms error in the order of about 10 meters, and that with predicted capability we can achieve relative position estimates in a reasonable time with an rms error in the order of ten centimeters.
Published in:	Proceedings of the 63rd Annual Meeting of The Institute of Navigation (2007) April 23 - 25, 2007 Royal Sonesta Hotel Cambridge, MA
Pages:	454 - 459
Cite this article:	Emadzadeh, A.A., Speyer, J.L., Hadaegh, F.Y., "A Parametric Study of Relative Navigation Using Pulsars," Proceedings of the 63rd Annual Meeting of The Institute of Navigation (2007), Cambridge, MA, April 2007, pp. 454-459.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In