No datum point zero calibration method of reconnaissance vehicle

A method to calibrate the zero position of reconnaissance vehicle in room was proposed. This method uses a dedicated zero calibration instrument and does not require the datum point. The dedicated zero calibration instrument combines the high-precision north finder, the level, and the calibration mirror with a zero accuracy of 0.15 mil. The method can effectively solve the zero calibration problem of reconnaissance vehicle under the conditions that the site or meteorological conditions are not satisfied.