Abstract
Technology demonstration satellite Earth Observatory - the TSUBAME has two main mission: Visible Earth observation; Measurement of polarization of hard X-ray photons from gamma-ray bursts (GRB). Attitude Determination System (ADS) of TSUBAME has the following sensors: Magnetometers (TAMs), Solar Sensors, MEMS gyro, Star Trackers, Fiber Optic Gyro (FOG), GPS receiver. To ensure satellite survival during each mission only several types of sensor will be used in order to minimize power consumption. This paper presents a robust algorithm using TAM and MEMS gyro sensors based on Unscented Kalman Filter (UKF) where both the three-axis attitude and gyro sensor biases are estimated. This algorithm will be used during sun pointing mode because of small power consumption of TAMs and MEMS gyro sensors. Numerical simulation example is given to certify the proposed algorithm and its estimation accuracy.
