Precise Sensor Orientation of High-Resolution Agile Optical Satellites With Star–Earth and Moon–Earth Collaborative Observations

Benefitting from the enhanced maneuverable imaging capability, an agile optical satellite could collect not only Earth images but also star images and Moon images, which provides a novel star–Earth and Moon–Earth collaborative observation mode. In this mode, the stars or lunar surface points could be considered as accurate control points to geometrically calibrate camera installation parameters (CIPs) in time. Aiming at such a novel mode, a feasible, precise sensor orientation method for high-resolution agile optical satellites with the star–Earth and Moon–Earth collaborative observations was presented. In the presented method, the CIPs were first calibrated with star images or Moon images, and then used to perform the sensor orientation of Earth images. The LuoJia3-02 panchromatic linear-array images were tested. The experimental results showed that the sensor orientation accuracy achieved by the star–Earth collaborative observation and the Moon–Earth collaborative observation was, respectively, 15.055 pixels and 13.692 pixels, which was almost the same as that in the conventional Earth observation. It demonstrates that the presented method could get rid of the high dependence on ground calibration fields in the conventional external geometric calibration. Moreover, it could calibrate the CIPs at a very high frequency (e.g., in each satellite orbit) and thereby improve the sensor orientation accuracy of optical satellite images.