中文摘要：

为了提高利用光学立体像对进行水下目标三维定位的精度，本文基于光线在空气和水体两种不同介质中的传播规律建立了光线折射改正模型。从航迹方向、航迹垂直平分线方向和普通情况三种角度讨论双介质摄影测量的几何关系，定量分析光线不严格相交造成的平面误差，并推导双介质折射改正公式。利用近景摄影条件下的立体像对验证折射改正方法的正确性，结果表明在实验室条件下，双介质摄影测量的相对测深精度优于3．5％。

英文摘要：

In this study, we develop a ray refraction correction model based on the propagation law of ray in water and air. Moreover, here we discuss the geometric relationships of two-medium photogrammetry from three different aspects including track direction, track perpendicular bisector direction, and general situation to improve the accuracy of positioning submerged targets by utilizing optical stereo pairs. The plane errors caused by different incident angles are quantitatively analyzed. Furthermore, the refraction correction equation is derived. The close-range stereo pair is used to verify the correctness and effectiveness of the proposed refraction correction procedure. The experimental results show that the relative bathymetry accuracy of the two-medium photogrammetry is better than 3. 5%under laboratorial conditions.