精密测角法中测量误差对内方位元素标定的影响

Measurement error impact on intrinsic parameters calibration in precise angle measurement method

通过误差传递推导误差公式,确定了各参数对内方位元素精度的影响关系。为了明确对相机内方位元素精度的影响因素,对像点位置坐标精度和物方视场角精度与相机内方位元素精度的关系进行研究。在现有的精密测角法的基础上,推导关系公式来确定各参数对内方位元素精度的影响关系。对采样点各个数据的精度及其组数对结果精度的影响进行讨论。结果表明:在像点位置坐标标准差1μm内,物方视场角极限误差0.7″内,位置坐标精度对主距f精度影响较大,而物方视场角精度对主点x0精度影响较大;测量数组数(采样点数)量对结果误差有很大的影响。实验证明:该影响与实际结果相符。

Based on the error propagation theory, the error formula was obtained for determining the relationship between the intrinsic parameters accuracy and all the other parameters. To define the factors for influencing the accuracy of camera intrinsic parameters, the accuracy relationship among the coordinates of image points, field of view of object and camera intrinsic parameters was studied. Based on the current precise angle measurement methods, the formula was deduced to determine the relationship between intrinsic parameters accuracy and all kinds of parameters. The impact of every data accuracy and its group numbers on the result was discussed. Results show that the accuracy of position coordinates has more effect on the principal distance f with the accuracy of standard deviation 1 μm for image coordinates, and extreme error 0.7＂ for field of view of object , the accuracy of location coordinates has more effect on the accuracy of principal distance f, while the accuracy of field of view of object has more effect on the accuracy of principal point x0.The number of sampling points affects the result greatly. The experimental results show that the impact matches the real cases.