Approaches to optimal inertial instrument calibration using slewing

Abstract

Calibration of an inertial measurement unit is important to the success of accuracy-sensitive missions. This thesis analyzes calibration techniques for two inertial measurement mechanizations: (1) an inertially stabilized system and (2) an inertially referenced slew. An inertially referenced slew rotates the inertial measurement unit with respect to an inertial reference frame independent of the vehicle motion. The appropriate inertially referenced slew is determined by a proposed optimal calibration method that maximizes the correlation between a measurement and a covector, specifying a mission performance index. The performances of a six-position dwell calibration (inertially stabilized system) and an optimal slewing calibration (inertially referenced slew) are determined to be dependent on the mission. The inertially stabilized system is preferred for determining accelerometer errors and an inertially referenced slew is preferred for calibrating rate-sensitive gyroscope errors.