Abstract: The spatial parallel between the receiving and transmitting optical axis of the atmospheric lidar system directly affects the validity of the detection data. The high precision optical self alignment system is one of the guarantee conditions for the reliable detection of the space borne lidar. Based on the existing international space borne atmospheric detection lidar, the research status, basic principle and common methods of the optical path adjustment system are summarized. The common echo signal intensity method and spot adjustment method are compared from two aspects of hardware structure and software algorithm. The structure of echo signal intensity method is simple, but the self alignment process is significantly affected by atmosphere and surface environment. Spot self alignment method can achieve 1μrad high precision adjustment, but the optical path is complex and the cost is relatively higher. In general, the optical self alignment technology involves many disciplines and fields. Combining the advantages of each discipline, it is the future development direction to design a simple structure but high precision and low cost optical path adjustment system.

Key words: space borne lidar, boresight automatic adjustment, echo signal intensity, light adjustment