Fast Star Map Recognition Method of Camera with Large Viewing Angle

It is necessary to calibrate the internal and external parameters of a camera with a large field of view in real time to measure the antenna profile of spacecraft with high accuracy in orbit via photogrammetry. In this paper, a fast recognition method for star map captured using a camera with a large viewing angle is presented. First, a star map recognition strategy combining calibration results is proposed to improve the matching accuracy. Next, a tag search and matching method based on the angular distance between four stars is proposed, which reduces the complexity to linearity and achieves fast and accurate matching. Finally, a matching test method based on back-casting error analysis is proposed to prevent false identification. The experimental results show that compared with the traditional algorithm, the method reflects both the recognition speed and recognition rate. The recognition rate reaches 99. 5%, and the recognition time is reduced by 75%. This study demonstrates that the proposed method is reasonable and effective, can save storage space, improve the recognition speed and rate of star maps, and has a good practical value.