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Calibration of Strapdown Magnetometers in Magnetic Field Domain |
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| Authors: | Demoz Gebre-Egziabher Gabriel H Elkaim J David Powell Bradford W Parkinson |
| Affiliation: | 1Assistant Professor, Dept. of Aerospace Engineering and Mechanics, Univ. of Minnesota, Twin Cities, 110 Union St., N.E., 107 Akerman Hall, Minneapolis, MN 55455. E-mail: gebre@aem.umn.edu 2Assistant Professor, Computer Engineering Dept., Univ. of California, Santa Cruz, 1156 High St., Santa Cruz, CA 95064. E-mail: elkaim@soe.ucsc.edu 3Professor Emeritus, Dept. of Aeronautics and Astronautics, Stanford Univ., Durand Building, 496 Lomita Mall, Stanford, CA 94305-4035. E-mail: jdpowell@stanford.edu 4Professor Emeritus, Dept. of Aeronautics and Astronautics, Stanford Univ., Durand Building, 496 Lomita Mall, Stanford, CA 94305-4035. E-mail: brad@relgyro.stanford.edu |
| Abstract: | This paper presents an algorithm for calibrating strapdown magnetometers in the magnetic field domain. In contrast to the traditional method of compass swinging, which computes a series of heading correction parameters and thus is limited to use with two-axis systems, this algorithm estimates magnetometer output errors directly. Therefore, this new algorithm can be used to calibrate a full three-axis magnetometer triad. The calibration algorithm uses an iterated, batch least-squares estimator that is initialized using a two-step nonlinear estimator. The algorithm is simulated to validate convergence characteristics and further validated on experimental data collected using a magnetometer triad. It is shown that the postcalibration residuals are small and result in a system with heading errors on the order of 1?to?2?degrees. |
| Keywords: | Calibration Magnetic fields Algorithms Aerospace engineering |