遥感相机中时间延时积分电荷耦合器件 积分级数的最优选择

针对时间延时积分电荷耦合器件积分级数对成像质量的影响,提出了一种航天遥感相机中时间延时积分电荷耦合器件积分级数的最优选择方法.构造了典型成像系统的信噪比与积分级数关系模型和调制传递函数与卫星姿态角和积分级数的函数模型;以信噪比和调制传递函数的容许值为约束条件,推导出了任意条件下时间延时积分电荷耦合器件的可选积分级数区间并给出了最优的积分级数解,给出了对应的增益设置指导函数.运用仿真实验对该方法进行验证,并与传统方法进行比较,结果表明:该方法能够选取最优的积分级数,从而获得满足信噪比和调制传递函数指标的最佳成像质量;若该值不存在,依然能获取相对最佳的折中值和视觉效果;同时,本文成像效果优于传统方法.

Selecting the Optimal Integral Grade for TDI CCD in Remote Sensing Cameras

In order to solve the problem that integral grade affects the imaging quality, a method of integral grade selection for remote sensing cameras is proposed. Firstly, a model of signal to noise ratio and integral grade is derived and another model of modulation transfer function, satellite attitude parameters, precision of the TDICCD’s line transfer frequency and integral grade is as well formulated. Then, the viable integral grade range is obtained under the restrictions of the SNR and MTF targets based on the above two models. Consequently, the gain of the imaging system versus the optimal integral grade is given. Finally, experiments and comparisons are made to validate the proposed method. The results indicate that: the optimal integral grade can be selected based on our method, and the best imaging effect can be accordingly obtained; when the optimal integral grade is nonexistent, a comparative good integral grade can be also acquired; the imaging effects obtained under the proposed method is better than that of the conventional ones.