Bias correction using background stars for space-based IR tracking

This paper proposes a methodology for removing sensor bias from a space-based infrared (IR) tracking system through the use of stars detected in the background field of the sensor. The tracking system consists of several satellites each equipped with a narrow-view IR sensor that provides bearing observations of the target. As stars are detected the instantaneous sensor pointing error can be calculated as the difference between star detection reading and the known position of the star. The system utilizes a separate bias filter to estimate the bias value based on these detections and adjust the target line of sight measurements accordingly. The target state is estimated through a linearized Kalman filter (LKF). Mean error results are given for the period when the target is in view of the satellite IR sensors. The results of this research provide a potential solution to bias correction while simultaneously tracking a target.