航相机像移补偿计算的坐标变换方法

Method of coordinate transformation for IM & IMC calculation in aerospace camera system

由于航空、航天照相要求的分辨力愈来愈高，对像移补偿系统的要求愈来愈高。要求对产生像移速度的诸因素考虑得更为全面，也就是影响像移速度的诸因素的测量精度和像移速度的计算模型要更精确。本文应用坐标变换方法进行了航相机的像移补偿计算。首先归纳了航空航天相机（简称航相机）中像移补偿的原理、技术途径和实现方法。其次给出航相机光学系统和运动形式的齐次坐标变换，实现了像移补偿计算模型的各个基本要素，从而提出了像移补偿计算的一般数学模型，此模型适用于各种航相机的像移速度和像移补偿计算。再次，对应用坐标变换方法进行像移补偿计算作了详细归纳，最后简单讨论了对像移速度矢量公式的简化方法和像移补偿误差计算方法，以期得到满足计算精度的简化表达式。通过计算模型四个环节的变化，可以将此方法应用到各类航相机像移补偿系统。

As the resolving power of aerospace photography is demanded to be higher, the precision of IMC (Image Motion Compensation) system must be higher. For this reason, the sources for inducing image motion need to be considered more comprehensively. Namely, the measurement precision for all factors that affect the IM and the calculating modle for IM should be more accurate. In this paper, the coordiante transform methods were used to calculate the IMC of aerospace camera system. Firstly, the theory, the technical ways and the methods for realizing IMC in aerospace camera system were concluded ; Secondly, in form of homogeneous matrix, all the coordinate transformation were summed up, from which all the basic parts of IMC mathematics calculation model were realized and a general mathematics model for calculating IMC was put forward; Thirdly, the calculation of IMC using coordinate transform methods were expatiated. Finally, the methods of simplifying the vector expression of IM velocity and calculating the error of IMC were discussed birefly, so as to obtain the precise and simplified expressions of IM velocity and error estimation of IMC. Through changing the four parts of the calculation model, the method can be applied to IMC systems of all sorts of aerospace cameras.