Research on influence of space-borne stereo mapping camera's time synchronization precision on attitude angle errors

摘要

Mapping precision of space-borne stereo mapping camera is primarily determined by attitude angle errors of the satellite. Time synchronization errors of space-borne stereo mapping camera will bring on extra attitude angle errors. In this paper model of space-borne stereo mapping camera was established in satellite tool kit (STK) to obtain the regularity of attitude angles changing with time. Influence of space-borne stereo mapping camera's time synchronization precision on attitude angle errors was analyzed by combing the regularity of attitude angles changing with time and the sampling theory. As a result digitalized model of extra attitude angle errors and time synchronization errors of space-borne stereo mapping camera was put forward. In validation experiments real attitude angle data of a stereo mapping satellite were collected and extra attitude angle errors caused by specific time synchronization errors of space-borne stereo mapping camera were obtained. Results of the experiments and analysis indicated that extra attitude angle errors caused by specific time synchronization error could be reduced from 0.01939 arc second to 0.00003879 arc second as time synchronization precision was optimized from 1ms to 20μs.