Impact of scan mirror stability on TDI CCD system measure accuracy

Abstract

Numerical simulation model of TDI CCD imaging is used to study the relationship between the speed stability of the scanning mirror and angle measurement accuracy in a TDI CCD measurement system. First,based on the physical process of TDI CCD push-broom imaging,a numerical simulation model is established to describe the whole process from optical image and scan mirror stability to digital images,and then gravity centre of image is calculated and the target angular coordinate is got; Monte Carlo method is used to complete a simulation experiment,and the statistical results could describe the relation between stability of the scanning mirror and measure accuracy. In the end,the speed stability of an engineering scanning mirror is substituted into the simulation module,and the simulation results show that the error increases by 5. 67 μrad,reached 1 /4 of pixel angular resolution. So in high-precision measurement,the comprehensive influence of the pixel angular resolution and the speed stability of the speed stability need to be considered. The appropriate speed stability of the scanning mirror showed be chosen to meet the requirement of pixel angular resolution.