Satellite Sensor Coverage Analysis Method Considering Composite Motion of Platform Attitude and Orbit

Objectives: The analysis of ground coverage of satellite payloads plays an important role in applications such as constellation communication, navigation, and remote sensing. With the development of satellite attitude control capability and payload technology, super agile Earth observation satellites can achieve imaging during attitude maneuvering. Methods: There is an urgent need to research methods for determining the payload coverage range of satellite platforms in scenarios involving orbital motion and attitude maneuvering. Firstly, based on the sensor visual element description method, a mathematical equation for calculating the intersection between the sensor’s line of sight and the Earth ellipsoid was established. By deriving the analytical solution of the intersection point, the instantaneous coverage area of any field of view on the Earth's surface can be obtained. Subsequently, based on the satellite motion model, a velocity calculation method for the intersection points between the payload's line of sight and the spherical surface has been derived, contributing to the calculation of coverage strips. Furthermore, considering the orbit and attitude motion of the satellite, a continuous coverage strip determination method based on envelope points is proposed, and envelope point criteria are given for conical and rectangular sensor fields based on projection point velocity vectors and sensor direction vectors. Results: Finally, three types of experiments are generated to validate the proposed algorithm, which include the verification of sensor instantaneous coverage, the verification of sensor coverage strips in orbit-only motion, and the verification of sensor coverage strips in attitude and orbit compound motion. By conducting simulation experiments for different scenarios with conical and rectangular sensor types, it has been found that the calculation efficiency of the instantaneous sensor coverage range is better than 0.01s. By comparing with the System Tool Kit (STK) software, the accuracy of the proposed method for determining the instantaneous coverage range and sensor coverage strips in the attitude and orbit compound motion can be verified. Conclusions: Extensive experiments show that the proposed method combines efficiency and accuracy, and can meet the requirements of sensor coverage analysis under the composite motion of satellite platform attitude and orbit.