基于模板的FY-2一级杂散光模拟

Simulating first order stray light of FY-2 VISSR using templates

对FY-2扫描辐射计的光机结构进行了简化,确定出在其南北步进中对杂散光模板变化产生影响的仅仅是折镜边缘,据此结论对产生一级杂散光的相关机械边框建立空间坐标,通过投影方法得出在任意步进位置的杂散光进入区域,并通过对杂散光区域的像元数计数和制作视频文件的方式检查其变化的连续性。从信号光分布最小的世界时19时图像出发,使用快速卷积的方法,进行了点光源、月牙状亮边和地球全图的模拟杂散光形成的计算,得出的结果与实际杂散光的现象较为接近,成为进一步以图像处理方式消除杂散光的基础。

By simplifying the framework of FY-2 VISSR, it was found that the influenceon the transform of first order stray light templates was the rotation of folding mirror edge. Based on the structural parameter of this instrument, those frameworks related to the stray light were discretely sampled, then those sampled points were projected to a plane to be observed by sensors, so the templates of the first order stray light at any angle of the folding mirror in this instrument were established. The continuity of those templates was examined. The forming of first order stray light was simulated with Gaussian point source, crescent-like edge and full disk of earth by convolution with the template, those outputs show the results are relatively close to the phenomenon of real images, and further quantitative suppressing of stray light will be on the way.