Research On The Methos Of Producting High-Quality DOM In Urban Areas

In recent years, unmanned aerial vehicle low-altitude remote sensing system, with its unique advantages has gotten more and more attention from the photogrammetry industry, and gradually expanded the scope of practical application. The images obtained by unmanned aerial vehicle with the characters like small size, large overlap and the big angle of dip, has brought a big challenge to the internal data processing industry.This paper meanly studies the use of urban areas image data obtained by the unmanned aerial vehicle low altitude remote sensing system, to product the high-quality digital ortho map, shorted for DOM, which includes the Digital Surface Model, shorted for DSM and Digital Elevation Model, shorted for DEM Acquisition Technology and the DOM mosaic Technology.1. This paper firstly analyses the character of the images obtained by the Unmanned Aerial Vehicle, and selects the Gaussian pyramid image matching strategy by comparing and analyzing the existing matching algorithms, to do the point extraction and matching to obtain dense point cloud DSM by Vertical Line Locus algorithms.2. Comparing the methods of the structure of the DEM, this paper selects the method of extracting buildings characteristic line by three-dimensional measure, and makes the characteristic line as constraints of the TIN construction. Finally, quickly search the point with spatial index technology to generate DEM by interpolating points.3. This paper researches the key technology of the DOM mosaic, such as dodging uniform color of images and the technology of selecting the mosaic line on the overlap image. This paper has compared the algorithm of dodging uniform color of images and got that the Mask dodging law and Wallis uniform color method are able to make the whole image with the same color. The method of selecting the mosaic line on the overlap images is by producing the overlap difference image, cutting 20% of the border images to improve the path search speed, and smoothing the certain area around the mosaic line to achieve the natural color transition of the overlap images.The paper basing on analyzing the characters of the urban area images by UAV system and the principle of the existing photogrammety software, researches a process to quickly produce the high quality DOM from the images that are colleted by the UAV system.