摘要:
Sea surface image has very limited texture information and low matching precision,which leads to significant error and poor stability in existing relative orientation method.An improved method was pro-posed to improve the accuracy and stability of relative orientation parameter calibration.The geometric model of the relative orientation and the coplanar equations were built,and the conditional adj ustment method with parameters were adopted to calculate the relative orientation parameters.For the convergence of the iteration,an initial value calculation method was developed.Two aspects were focused in this paper to improve the accuracy and stability of the relative orientation parameters,with a detailed calculation process. One aspect refers to selecting the points of characteristics in the photographic region as uniformly as possi-ble,and implementing the high-precision matching method for image matching,The other refers to selecting the optimal matching points (no less than 300)in a large number of conjugate point pairs (no less than 1 000)to calculate relative orientation parameters.In the offshore experiment,we eliminated the points of coarse error and significant errors from the 1 200 conjugate points,and obtained the accurate rela-tive orientation parameter calculated by 321 optimal matching conjugate points,so the feasibility of the method described in this paper has been verified.Method developed in this study solves the problem of low accuracy and poor stability of the relative orientation calibration,and improves the reliability of the stereo photogrammetry for ocean wave measurement,which is beneficial to its popularization and application.%海面影像的纹理信息少、匹配精度低致使现有的相对定向方法误差大,稳定性差;通过对其进行改进,有效地提高了相对定向参数标定的精度和稳定性.文中建议了几何模型,并以共面方程为控制方程,采用附有参数的条件平差法计算相对定向参数,同时发展了初始值计算方法,保证了迭代的收敛性.从两个方面入手提高相对定向参数标定的精度和稳定性,并给出了详细的计算流程:1)在摄影区域内近似均匀的选取特征点,并采用高精度的匹配方法进行影像匹配;2)在大量的共轭点对(不低于1000个)中选取最优匹配点(不低于300个)进行相对定向参数计算.海面实测数据分析时通过迭代的方式在1200个共轭点中逐渐剔除了粗差点和误差较大点,最终得到了由321个最优匹配共轭点计算出的精确相对定向参数,检验了所述方法的可行性.该研究解决了相对定向标定精度低、稳定性差的问题,提高了立体摄影海浪测量技术的可靠性,有利于其推广和应用.