In-orbit calibration of normalized magnetometer measurements

Magnetometers are widely used for LEO small satellites for attitude determination and control system. A normalization of the magnetic field vectors is performed, since the values are very big, respectively, leading to numerical problems in matrix computations. Normalizing of vector information is suggested, since it is only the direction of the vectors and not the magnitude that is important for attitude estimation. In order to estimate satellite dynamics and control attitude accurately, scale factor and bias of normalized magnetometer measurements must be estimated. In this study, a Linear Kalman filter (LKF) based algorithm in order to estimate the biases and scale factors of the normalized magnetometer measurements is proposed. The proposed calibration algorithm is simulated through the attitude dynamics of a small satellite for estimating the biases and scale factors of the normalized magnetometer measurements. Simulation results show that it is possible to estimate both normalized magnetometer measurements biases and scale factors with high accuracy using the proposed algorithm.