Compensation method of heading effect for inertial navigation system based on Fourier decomposition of temperature variation

Heading effect is one of the most challenging problems of high accuracy space-stable platform inertial navigation systems. With system heading changing experiment data, the affection theory of heading changing to variations of temperature and platform drift is analyzed, and the relationship between platform drift variation and temperature variation is discussed. In sequence, a compensation method of heading effect based on Fourier decomposition of temperature variation is proposed. Moving least-squares fitting of navigation errors is adopted to withdraw the actual series of platform constant drift, which are thereafter the observations for calibrating temperature coefficients of platform drift. Multiple heading changing experiments are conducted to verify the proposed method. The results show that there exists strong correlation between platform constant drift variation and the amplitudes of fundamental wave of temperature variation, and the heading effect errors due to temperature variation may be reduced by 40% to 90% with the proposed compensation method, which has significant potential for engineering application.