Zero calibration method for strapdown inertial navigation system

The invention discloses a zero calibration method for a strapdown inertial navigation system and solves the problem that the evaluation precision of a zero error is influenced by a non-orthogonal error of measured inertial components in the conventional zero calibration method. The method comprises the following steps of: mounting an inertial device onto a three-axle table, rotating the three-axle table to four designated positions, and carrying out accumulation and elimination on additional error components received by the four measured inertial components on the different positions due to an installation error, so as to obtain the zero errors of the inertial components. According to the novel zero calibration measuring method provided by the invention, the influenced caused by the installation error can be effectively compensated, so that the relatively accurate zero offset can be obtained, and the system accuracy is improved. The method provided by the invention can be applied to the zero calibration of navigation systems of modern weaponries.