High-Accuracy Real-Time Attitude Determination and Imagery Positioning System for Satellite-Based Remote Sensing

The precise attitude determination and imagery positioning is crucial for remote sensing satellites to accomplish diverse observation missions. However, the complex fluctuations of environmental conditions result in severe and time-variant camera misalignment, which degrades the inertial attitude determination precision of optical payloads greatly and further hinders the improvement of positioning accuracy. Here, we develop a high-accuracy real-time attitude determination and imagery positioning system. With multiple laser sources integrated on the camera focal plane and a retroreflector reflecting the laser into a star tracker, the active optical monitoring path between the camera and the star tracker is constructed and provides the ability to monitor the camera misalignment. Using a dichroic mirror, the star tracker can detect the stars and the laser simultaneously. Then, the camera attitude determination and imagery positioning model based on the "star-laser" joint detection is established, which can precisely monitor the camera misalignment by the laser imaging and determine the inertial camera attitude combined with the star imaging. The ground simulation experiment is conducted and the results demonstrate the accuracy and effectiveness of the proposed method in monitoring the camera misalignment. Therefore, the proposed method provides an innovative idea for high-accuracy positioning.