航天器平台在轨振动对遥感成像质量的影响

Satellite platform on-orbit vibration's influence to image quality of remote sensing

由航天器上反作用飞轮、太阳帆板等部件产生的平台在轨振动是影响高分辨率遥感器成像质量的重要因素。基于LANDSAT-4平台模拟振动谱建立了平台在轨振动环境下遥感成像模型,讨论了航天器平台振动谱中各典型振动信号成分的强度对像质的影响,并将各振动成分依照对像质的影响强烈程度进行了排序,指出均匀白噪声成分所引起的颤振对像质的影响超过低通噪声成分所引起的像移。讨论了低通噪声成分的频谱形状与像质之间的关系,给出了带宽与噪声增益之间的拟合公式。通过搭建硬件实验平台,对仿真结果进行了验证。研究结果为航天器平台与遥感器隔振设计分析提供了依据。

Spacecraft platform onorbit vibration produced by reaction wheels and solar panels is important factor to image quality on high resolution remote sensing. The imaging model is constructed under onorbit vibration circumstances based on simulated vibration spectrums of LANDSAT 4 platform. Typical components of vibration disturbances＇ affec tion to image degradation are discussed, and sequenced by degradation magnitude to image quality. It is pointed out that jitter caused by uniform white noise component makes image quality degraded more than smear caused by lowpass noise component. Affection of lowpass noise spectrum shape to image quality is discussed, and fitting formula for bandwidth to noise gain is provided. Simulation results are verified by imaging testbed. It provides foundation for vibration suppres sion analysis and design of spacecraft platform and remote sensor.