Imaging Velocity Fields Analysis of Space Camera for Dynamic Circular Scanning

Compared with traditional push-broom imaging, the space camera that performs the new circular scanning imaging can effectively enlarge the imaging area and obtain high-resolution images. However, the imaging velocity fields of space camera will seriously deteriorate the image quality in the circular scanning imaging process. And the velocity fields are anisotropically distributed due to various factors, including attitude maneuvering, satellite precession, earth curvature, and earth rotation. Therefore, this paper proposes a mathematical model of the velocity field to analyze the effect of circular scanning imaging. Based on the principle of ray tracing, the expression of the instantaneous velocity field on the ground is first derived, and then the corresponding image velocity field is obtained by mapping the velocity vector to the focal plane. In addition, numerical simulations and image simulations are performed to analyze the anisotropy distribution of the velocity vectors. Moreover, the dynamic characteristics of the space camera are analyzed to evaluate the performance of this new imaging. The simulation results show that the higher velocity leads to worse imaging quality. The study of this paper provides guidance for attitude planning and imaging assessment for new remote sensing imaging of space cameras.