从船侧倾斜拍摄图像中提取海冰密集度的方法

A method to obtain sea ice concentration from oblique images on shipboard

为消除提取海冰密集度时因摄影镜头倾斜造成图像变形可能引起的误差,基于摄影测量学原理,对倾斜拍摄引起的图像变形进行修正,建立从倾斜拍摄的图像中提取海冰密集度的精确方法和相应的简化算法.以2006年德国南极威德尔海冬季考察中获取的图像为例,讨论了现场观测时的系统标定方法和不同算法的计算结果.对比分析验证了图像变形修正的必要性,说明简化算法能够同时保证海冰密集度计算的精度和效率.

To avoid the considerable errors of sea ice concentration from oblique images caused by camera lens inclination, the image distortion induced by oblique photography was quantitatively estimated based on photogrammetry theory, and an accurate method to obtain sea ice concentration from oblique images was developed as well as a corresponding simplified method. Thereafter, oblique sea ice images during German winter Weddell Sea research expedition in 2006 were presented as examples to discuss the system calibration in field investigation and the sea ice concentration obtained by using different methods. Results reveal the necessity to modify the image distortion induced by oblique photography and the power of the simplified method to ensure both precision and efficiency in calculation.