离轴三反宽视场空间相机的辐射定标

离轴三反(TMA)光学系统是目前最先进的空间对地观测相机的光学系统。本文在分析离轴TMA宽视场空间相机成像机理的基础上,针对其光学系统光路和结构的特点,提出了分视场定标和利用特殊开口形状积分球的全视场定标两种方案,并采用两种定标方案分别对离轴TMA宽视场空间相机两个不同阶段的样机进行了实验室辐射定标,定标结果表明两种方案切实可行,满足该相机实验室辐射定标要求。通过对提出的两种实验室辐射定标方案优缺点的分析,得出两种定标方案不同的使用条件,结果显示两种定标方案的定标精度分别为1.68%和1.89%。

Radiometric calibration of off-axis three-mirror-anastigmat space camera with wide viewing field

Off-axis Three-Mirror-Anastigmat(TMA)optical system is a most advanced optical system used in space cameras for earth observation presently. In this paper,the imaging mechanism of a off-axis TMA wide viewing field space camera is analyzed, and two kinds of calibration projects, sectional viewing field radiometric calibration and entire viewing field radiometric calibration using an especial hatch integrating sphere,are proposed according to the path and construction features of the off-axis TMA optical system.Then, Both the projects are used in the laboratory radiometric calibration for the different phase specimens of the off-axis TMA space camera. The calibration result indicates that both of the projects are feasible and can fully satisfy the requirements of laboratory radiometric calibration. The service conditions of the two projects are obtained by analyzing the relative merits of the projects. It is concluded that the calibration accuracies of two projects are 1.68% and 1.89%,respectively.