空间光学平台调偏流分析

为减小偏流角对TDI-CCD(Time-Delay Integration-Charge Coupled Device,时间延迟积分-电荷耦合器件)相机成像的影响,分析了侧摆成像时偏流角产生的原因和计算方法,定量计算了偏流角在沿航方向和穿航方向产生的像移,并通过仿真分析了偏流角影响因素及其残差对成像的影响.最后通过实际飞行试验发现,平台调偏流时偏航方向的姿态角存在振荡,即偏流角存在残差.经分析,此现象产生原因除了卫星平台本身的姿态扰动外,主要是卫星平台响应机制,即卫星平台对调偏响应过慢导致平台调偏流出现超调现象.该分析结果对空间光学相机平台改进有一定的参考价值,并已应用于某型号卫星的改进型.

Analysis of Drift Adjusting by a Space Optical Camera Platform

To reduce the image loss of Time-Delay Integration-Charge Coupled Device (TDI-CCD)camera caused by drift angle,some causation and calculation methods of drift angle are analyzed,and some quantitative computational formula for the influence on image quality were also introduced. Moreover,the influence factors of drift angle and the image motion on the along and across track caused by it were studied by simulation. Some phenomena appeared on the actual flight experiment,e.g.,the yaw angle was instable during drift adj usting by satellite platform and this caused drift angle error and then decreased image quality. By analysis,the above problem was discovered in the re-sponse mechanism of satellite platform. On account of design defects of the satellite platform,it responded to drift angle delivered by camera so slowly that the drift adj usting by platform lagged behind imaging. The analysis results contributed to improvement on a space optical camera platform and will be applied to the second generation satellite.