含有DEM误差的立体正射影像对上高程量测精度探讨

Measuring Elevation Precision on Orthophoto Stereo Pairs Including DEM Errors

在DEM支持下,通过引入投影视差光线,以数字正射影像为基础,制作立体辅助影像,并与原正射影像共同构建正射立体影像对,产生与实地相似的几何模型,进行立体观察与量测,可以量测地貌高程,是另外一种构建立体三维环境的思路。然而生成正射影像和辅助影像的原始DEM是含量有误差的。这种误差是否会对产生的立体正射影像对的高程量测结果产生粗差,进而是否影响立体正射影像对的后续使用,这是分析探讨的出发点。理论和实践证明,使用该DEM生成正射立体影像对的左右视差并不受DEM误差的影响,量测高程能够达到一定的精度要求。

The artificial introduction setting projection parallax light of generating aided stereo images based on digital orthophoto map supported by DEM and establishing stereo orthophoto pairs using the original digital orthophoto map and the aided stereo image are discussed,which can build similarity geometric model and conduct stereo observation and survey elevation.This is another thinking of building three-dimension stereo model environment.But this original DEM has errors,which would cause the blunder in measuring elevation on stereo orthophoto pairs and affect the use of the orthophoto pairs afterwards,should be studied.It is proved from the theory and practice,the horizontal parallax of the stereo orthophoto pairs has no affection from DEM errors and the elevation precision can reach some requirement from.