On-Orbit Measurement and Analysis of the Micro-vibration in a Remote-Sensing Satellite

With the improvement of the image resolution produced by remote-sensing satellites, the cameras onboard are increasingly sensitive to the micro-vibration caused by the moving parts of the satellite buses. The disturbance measurement in ground tests is often with low confidence, since the dynamic characteristics of the moving parts as well as the satellite structure are strongly influenced by many environmental factors which are quite different in space, such as atmosphere pressure, air damping or acoustic transmission. Therefore, on-orbit micro-vibration measurement is an important way to learn the characteristics of the disturbing source and the micro-vibration transmission along with the satellite structure in vacuum and weightless environment. In the present study, the on-orbit micro-vibration measurement system onboard a remote-sensing satellite is introduced. The measured data are analysed in three aspects of background noise level, disturbance source characteristics, and satellite structure transmission characteristics. From the measured data, it is found that local vibration caused by control moment gyro (CMG) and momentum wheels have the highest level, while the vibration transmitted to the payload is mainly caused by CMG and two-axis antenna. The response at the payload interface is much lower than the disturbance source interface, which means that the vibration level is attenuated largely by the satellite structure.