Modeling and Calibration of Wide Range of Motion Biaxial Inclinometers for Celestial Navigation

Celestial Geolocalization using a star tracker is a promising method to expand on the abilities of sun sensor based celestial navigation systems used by planetary rovers. Realizing this improvement requires developing methods to improve inclinometer accuracy, in this paper we examine methods for characterizing and calibration biaxial inclinometers with the goal of reaching an accuracy of 0.004° over a wide range of motion. We examine electrolytic and MEMS inclinometers and test a number of models found in literature that describe the relationship between the measurements and the inclinometer frame gravity vector. We compare these models to our own formulation and were able to successfully validate our projection model to better than the desired accuracy.