Aspects of Pulsar Navigation for Deep Space Mission Applications

This paper investigates the performance of pulsar-based navigation in deep space mission applications. The noise properties of X-ray based and radio-baspulsar measurements are examined and compared. A closed form parametric covariance analysis tool was developed in this study. It provides a rough estimate of the navigation performance associated with a deep space cruise that makes use of ion thrusters and sequential pulsar observations. In addition, the flight trajectory of the Dawn spacecraft was used to form a hypothetical deep space mission scenario that utilizes pulsars as navigation beacons. This simulated scenario accounts for clock uncertainty, pulsar timing noise, maneuver execution errors, sequential observation and interruptions between pulsar observations. A particle filter was implemented to reduce the large initial position uncertainty by resolving the number of pulsar wavelengths between the spacecraft and the Solar System Barycenter. The resulting position and velocity uncertainties from the particle filter can be used to initialize an Extended Kalman Filter, which estimates the spacecraft position and velocity for steady state operations.