Two-Stage Linear and Nonlinear Kalman Filters for Calibration of Magnetometers in Orbit

To accurately estimate satellite dynamics and control orientation, the magnetometer's scale factor and bias must be established. The magnetometer scale factor and bias change due to temperature variation and thermal deformation of the structure, creating a fairly significant magnitude error that needs to be minimized to meet mission requirements. This work proposes a two-step method employing linear and nonlinear Kalman filters to determine orbital magnetometer biases and scale factors. To accurately estimate satellite dynamics and control attitude, the magnetometer's scale factor and bias must be established. In this work, the bias error and scale factor error are treated as similar equivalent bias noise, and this bias noise is removed from magnetometer measurements.