Influence of Micro-Vibration Caused by Momentum Wheel on the Imaging Quality of Space Camera

Abstract

With the continuous improvement of the earth observation resolution of space camera, the micro-vibration dynamic environment caused by momentum wheel becomes one of the key factors that affect the imaging quality of space camera on orbit. The space camera is installed on the satellite platform, then the micro-vibration environment tests with multiple momentum wheels at different running states are carried out the ground, and the transmission characteristics of acceleration responses from vibration sources to space cameras are obtained. According to the experimental data, the finite element model of the satellite is modified. The measured acceleration excitation is applied to the position of the momentum wheel of the satellite finite element model, and the rotation angles of the optical mirrors are obtained by processing the MATLAB program. Through comparison, it is found that the momentum wheel that causes the maximum acceleration response is not necessarily the largest of the rotation angle of the mirrors. Therefore, it is limited to judge the imaging quality caused by each momentum wheel simply by the magnitude of acceleration response. Combining the optical system and the imaging parameters of the camera, it is found that the influence of the momentum wheel micro-vibration on the image quality is mainly the distortion. Finally, the distorted image caused by the micro-vibration is obtained through the simulation of the standard target image, and it is compared with the on-orbit image of the camera, and found that the simulation result is consistent with the visual effect of the on-orbit image. It is proved that the micro-vibration analysis method in this paper can provide some reference for the quality prediction of the on-orbit image.