Image Motion and Quality in Polar Imaging with a Large Wide-Space TDI Camera

Wide-field-of-view imaging using remote-sensing cameras is of great significance in the study of polar environments. However, because of the drastic change in the direction of Earth’s rotation velocity near the polar regions, image-shift analysis and image quality changes in polar images by large wide-space time-delayed integration (TDI) cameras are poorly understood. Therefore, in this study, a novel velocity projection method was used to obtain a mathematical model of the image-shift velocity field. A quantitative analysis of the simulation showed that the anisotropy of the instantaneous image-shift velocity field varied significantly from low to high latitudes, and rapidly decreased to zero at a very low instantaneous point when there was no anisotropy. After correcting for the camera travelling frequency and bias angle, the value of the modulation transfer function at the edges decreased by less than 5% at 196 levels of integration. Thus, a theoretical basis was provided for using a large wide-space TDI camera to photograph high latitudes. The findings of this study provide a theoretical reference for the current large field-of-view space cameras to obtain high-latitude target information for the edge fuzzy degradation problem.