In flight magnetometer calibration in the projectile frame

The use of magnetometers in low-cost navigation unit is promising because of their ability to assess the projectile attitude relatively to a direct external reference. However due to the physical principle of the sensor, the manufacture process and the environment, raw magnetometers signals cannot be used directly in a navigation filter. The development of in-flight calibration process is a significant step so that magnetometer can be used in an operational context. In this paper we present an improved magnetometer calibration algorithm using solely gyroscopes information. The performance of the algorithm is demonstrated with realistic simulation data of fin stabilized projectiles and the sensitivity of the estimated calibration parameters to gyroscopes errors is discussed. Finally the method is applied on free flight tests and shows satisfactory results.