Calibration of Sensors for Attitude Determination on CubeSats for Optical Inter-Satellite Links

Abstract

This thesis describes calibration routines for inertial measurement units, namely two gyroscopes and one magnetometer, used in the CubeISL project at the German Aerospace Center. Optimizing optical inter-satellite links, a promising technology in the rapidly growing CubeSat sector, is the projects primary goal. Due to the investigated algorithms, the sensors will provide precise attitude information and ensure a faster and more stable optical communication link acquisition. Calibration of the gyroscopes occurs in a lab environment. The results show a valuable decrease in cross-axis sensitivity and functional scaling. Determination of the sensor bias increases the stability of the calculated angles to gain more meaningful relative attitude information. Finally, the calibration results in the lab environment are verified with an optical link. Thus, mounting differences between the attitude sensors and the four-quadrant diode sensor are also resolved and analyzed. Magnetic disturbances in the lab environment impede verification, so tests outdoors are conducted. Both implemented algorithms work well in different scenarios and increase the sensor’s performance. Further analysis must be executed in the future to determine the superior choice. All examined algorithms are suitable for on-orbit calibration, allowing the flexible compensation of errors caused by heavy loads during launch.