GENERATION OF EPIPOLAR IMAGES FOR VERY HIGH SPATIAL RESOLUTION SATELLITES WITH PUSHBROOM GEOMETRY

3D information is useful and important in remote sensing analysis of natural terrains and man-made features. In order to extract 3D information, a common method is to construct map from a stereo pair of images. Epipolar images, which are corrected by epipolar geometry, are often used to simplify the construction of stereo models. The epipolar geometry is a geometric model of stereo vision. It is conventionally used with frame imagery. However, most remote sensing satellites acquire images with pushbroom sensors which call for a different implementation of the epipolar geometry. In frame images, we can search corresponding image points in epipolar lines. Whereas in pushbroom images, each scan line is a perspective center, so the epipolar line of a pushbroom image is generally not a straight line. The epipolar processing procedures developed for frame images cannot be applied directly to pushbroom images. Here we developed a method of generating epipolar images from pushbroom images and implemented it on very high spatial resolution WorldView-2 satellite images for generating stereo models of buildings. The method consists of three steps. The RPC is first used to build the geometry model and the direction of epipolar line is then estimated. Finally, the epipolar images are generated by image rectification and resampling. Our results indicate that the proposed method can simply and accurately generate epipolar images, which are also well qualified for image matching in 3D model generation. 1