用一台数码相机拍摄同心圆靶标的照片, 求出照片中这两个椭圆的方程。研究了一种解算方法, 能用这两个椭圆方程的系数直接算出同心圆靶面的姿态。再求出椭圆平行于透视轴的切线及其切点的位置。利用这些切点的坐标解算同心圆圆心的像点位置和相机的焦距。如果知道同心圆的半径还可以求出同心圆靶的位置。所提方法可在停机坪标定飞机上的方向舵的角位移传感器; 或用于追踪航天器自主测量目标航天器的相对位置姿态。

Takes a picture of the concentric circle target with a digital camera. Finds out the equation of each ellipse in the picture. An algorithm has been designed to calculate the attitude of the concentric circle target by directly utilizing these ellipse-equation coefficients. Finds out the ellipses' tangent lines parallel to perspective axis and gets the positions of their tangent points. Using coordinates of these tangent points, the imaged position of concentric circle center and the focal length of the camera can be calculated out. If the radii of concentric circle are known, the position of concentric circle target can be obtained. This method can be used to calibrate angular-displacement-sensor of plane's rudders. And it can be used to autonomously measure the relative position and attitude of target spacecraft from tracking spacecraft.