Reasearch on spaceborn TDI CCD camera imaging simulation based on Monte-Carlo ray tracing

Remote sensing camera imaging simulation can analysis effects on camera parameters, imaging environment, platform characteristics quantificationally. So it has important significance. This paper implements spaceborn TDI CCD camera imaging simulation with Monte Carlo ray tracing method. On the basis of assimilating strongpoint of conventional ray tracing, it pays attention to special imaging characteristics of sensor and other correlative factors, and brings forward retrorse Monte Carlo ray tracing method aiming at spaceborn sensor imaging simulation. It divides the simulation into several process, i.e. ascertain fixing center of CCD, create start list of rays, create in-pupil rays, rays in the satellite body, rays in orbit coordinate, rays on earth, compute the point of intersection and normal, get the luminance of the point, get the luminance of in-pupil, get the average luminance in integration time region, sensor response synthetically and output of digital image. The sample time and space distribution of original rays adopt Monte Carlo sampling method. In the ray tracing process, it strings factors such as atmosphere, PSF of optical system, motorial characteristic of platform, object radiation character, heterogeneous response character of sensor, radiant resolving power and noise, which are rarely involved in traditional ray tracing. It implements full link simulation of spaceborn TDI CCD camera.