Regional Network Adjustment And DEM Automatic Generation Based On The Unmanned Aerial Vehicle Image

With the rapid development of the unmanned spacecraft platform in the fieldof photogrammetry and the development of national infrastructure, Quick access togeographic data, the mapping of the area without people and the need foremergency disaster and the lower cost of unmanned aerial vehicles, makingunmanned aircraft come into people’s vision with a unimagined speed ofdevelopment applications. Obviously, the aim of the application of unmannedaircraft is to get the geographic data we want. The corresponding UAV image dataprocessing has become a key issue we want to solve.This paper outlines the research status of digital photogrammetry and the keyproblems existed, describes the significance of this study as well as the researchcondition of UAV image data processing and the existed key problems. The mainresearch content of the article include:(1)The image pre-processing of UAV images. Mainly describes the cameradistortion correction, DLT transformation is used in this paper; Interpolation isused in image distortion correction and the wallis filtering is used in processing theimage.(2)Feature extraction and image matching. In the algorithm of featureextraction, the feature extraction theory by the Harris is emphatically elaborated;In the image matching, this paper briefly introduces the generation of pyramidsimage and the image matching of correlation coefficient method, and somematching constraints which are used in matching are described; and then the pixellevel matching---least squares matching is also described.(3)The adjustment of regional network and the generation of DEM. the basiccoordinate system used in the experimental system is introduced; algorithm ofcontinuous relative orientation to construct three-dimensional model﹑model building to connect free navigation network、 absolute orientation to solveapproximate coordinate of the ground point and the adjustment of overall networkare researched; the method of DEM automatic generation algorithm based on thesurface fitting is realized. Finally, the author puts forward the proposals about theproblem which exists in unmanned spacecraft image processing experiment systemand illustrates the content of further research and problems to be solved.