The Methods Study Of Establishing And Application For The Line Digital Terrain Model Based On Digital Photogrammetry

With continuously improvement of railway network structure and unceasingly expansionof construction scale, it needs to introduce more new technology to improve design efficiencyand scientific level in the field of railway’s survey and design. Digital photogrammetrytechnology has many distinguishing features, such as high precision, high efficiency andautomatically generating the data of the ground. This technology provides the best interface ofgenerating large strip digital terrain model in the railway line design. And it improves thedesign efficiency and plays a very important role on the research of digital terrain modelestablishment and application methods based on digital photogrammetry.This paper mainly studied the following aspects:(1) The data acquisition mode of digital elevation modelIt researches data acquisition mode of digital elevation model, and studied acquisitionmethods and technology process of obtaining DEM by digital photogrammetric.(2) Data structure and interpolation method of digital terrain modelIt analyses data structure and the interpolation method of frequently-used digital terrainmodel, and puts forward data interpolation method which is suitable for digitalphotogrammetric.(3) TIN modeling method of digital terrain modelIt deeply analyses the TIN modeling method for large strip digital terrain model, andfurther studied TIN modeling methods and skills of the digital photogrammetry. Consideringcharacteristics of DEM model, it constructed constraint Delaunay triangle network byinserting constrained edge in the constraint Delaunay triangle network. In this way, the digitalterrain model based on the digital photogrammetry can be better got.(4) Generation and application of digital photogrammetric modelIt researched data storage structure of digital photogrammetric, and studied theinterpolation method of railway lines’ ground elevation and calculation methods of conditionsby using engineering examples. In the paper, it also put forward calculation method of sidepiling. Using bilinear interpolation solved the calculation of ground elevation. Under thecondition of drawing up the vertical section, using least square method to match the crosssection and design the calculation algorithms for earthwork. In the papers, it preliminary studied the generation of digital terrain model andengineering applications of the digital photogrammetry. The research results also can be areference for the applications of the digital terrain model.