提出一种实用的基于物方投影基准面的线阵推扫式卫星影像核线模型,研究并实现基于该模型的近似核线影像生成方法。该方法能够生成子像素级上下视差的近乎严格的核线影像,且能直接由立体影像的定向参数建立原始影像与核线影像之间的严格坐标对应关系;基于投影基准面进行近似核线排列,有利于生成分辨率一致、相对于物方水平的核线立体模型,方便进行立体量测和立体判读。为了验证本文方法的正确性、可行性和通用性,分别对带有高精度RPC的SPOT5-HRG异轨立体像对、IKONOS同轨立体像对、IRS-P5同轨立体像对以及Quickbird同轨立体像对进行了核线试验。目前,该方法已应用于卫星影像的立体测图和DEM自动生成软件模块中。
This paper proposes a practical epipolarity model for linear pushbroom satellite stereo-imagery based on the projection reference plane(PRP)of object-space,and realizes a new method for generating approximate epipolar images according to such model.By adopting this method,quasi-rigorous epipolar image pairs with the subpixel level of vertical-parallaxes are available,and the coordinates corresponding relationship between the original image pixel and the epipolar image pixel can be easily derived from the orientation data of satellite stereo-imagery;besides, by rearranging the approximate epipolar lines on the defined PRP, the stereoscopic model that is horizon- tal to the object-space and with consistent resolution is obtained, thus quite convenient for 3D measurement and in- terpretation. In our experiments, the approximate epipolar images of SPOTS-HRG across-track stereo-imagery, IKONOS along-track stereo-imagery, IRS-P5 along-track stereo-imagery and Quickbird along-track stereo-imagery are respectively generated, which demonstrates the feasibility, correctness and universality of our method. Now, this method has been successfully applied in the stereo-mapping and automated DEM generation software modules of satellite linear pushbroom images.