Air-to-water Photogrammetric Intersection Using Frame Imagery

摘要

The object-to-image correspondence of frame imagery is based on perspective projection, and the image point, perspective center, and object point are confined to the collinearity property if single medium of imaging is considered. The refraction effect would bend the imaging ray when it comes to passing different media. Therefore, the geometric relationship between image space and object space needs to correctly trace the whole path of imaging ray travelling in varied media to support a quality photogrammetric mission. This study aims to develop a rigorous model dealing with the air-to-water photogrammetric intersection using frame imagery to not only decide the precise three-dimensional coordinates of underwater object point but also compare the rigorous solution with the results that impose no refraction correction and a water depth approximate refraction correction model. The amount of deviations and the deviations of locality are to be discussed and analyzed. In addition, the impact of error sources of image point measurement, orientation parameters, water surface, and refractive index of water body on the quality of three-dimensional coordinate determination of underwater object point has been studied to better realize air-to-water photogrammetric intersection.