Photoelectric pod drift calibration method based on navigation system

The accuracy of stability control is an important indicator of photoelectric pod system. In order to reduce the effect of gyro drift on stability accuracy in stabilized sighting control, the gyro drift needs to be compensated. A method of drift measurement and compensation was introduced for the photoelectric pod based on the navigation system, which was designed to calculate the component of earth rotation in the platform by the position and attitude data of airborne navigation system and pod angle during drift measurement phase of photoelectric pod, so as to obtain a more accurate gyro error. And in the stable phase, the gyro error and earth rotation component were compensated respectively by the navigation system. This method could effectively separate the earth rotation component and gyro error in the gyro drift measurement stage and adjust earth rotation component in the stable stage, so that the stability precision of stabilized sighting system could be improved. The experimental results show that, by comparing the results of 10-minute traditional drift measurement and drift measurement based on the navigation system, the accumulated drift error is stably controlled, the pitch angle is reduced from 1.80° in traditional method to 0.04°, and the heading angle is reduced from 0.77° to 0.04°.