Sampson-distance based ellipse fitting for calibration of magnetic compass deviations
LUO Shouhong1,2, ZHANG Rong1, GUO Meifeng1, PENG Zhuo1
1. Engineering Research Center for Navigation Technology, Department of Precision Instruments, Tsinghua University, Beijing 100084, China;
2. Beijing Aeronautical Technology Research Center, Beijing 100076, China
Abstract：Magnetic compasses are widely used in civil and military navigation applications but they are susceptible to magnetic disturbances in the environment. Thus, the compasses must be calibrated for the magnetic effects in the environment after installation. The calibration also improves the compass accuracy. An analysis of the effects of magnetic disturbances showed that the ellipse output assumption in the Sampson-distance based ellipse fitting method could be used to fit raw magnetic compass measurements. Then, the fitting coefficients are used to calibrate the compass readings to compensate for the environmental disturbances to improve the heading accuracy. A multi-position turntable experiment was used to calibrate a C100 two-dimensional magnetic compass fabricated by KVH. After calibration, the mean heading error was reduced from 1.5° to 0.25°, which illustrates the validity and practicality of this method.
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2016, Vol. 56 
