Attitude Guidance Algorithms for Agile Satellite Dynamic Imaging

Abstract

Dynamic imaging modes are increasingly crucial for agile satellites to perform complicated Earth observation tasks. In this study, a direct guidance algorithm is developed to calculate the reference attitude and velocity for dynamic imaging mode from target geolocation information while considering the constraints on both the satellite camera boresight axis and the image motion vector. The two slew angles are determined directly, and no rotation around the boresight or reference vector is required. The proposed approach employs a direct solution instead of the iterative process to obtain the reference attitude, which releases the onboard control system from the intensive computational load. To illustrate the performance of the proposed guidance algorithms, numerical simulation results are presented.