A Method for Automatic Correction of Digital Ground Elevation Model in Low Altitude Aerial Photogrammetry

Abstract

The invention discloses a method for automatically correcting a digital ground elevation model in low-altitude aerial photogrammetry, which includes the following steps: a) using digital aerial images of target objects captured by low-altitude drones to generate digital surface model point clouds; b) on the digital surface Extract target points with steep elevation changes from the model point cloud; c) Use the target points extracted in step "b)" to extract the edge contours of the target object; d) Correct the edge contours of the target object extracted in step "c)" elevation value. This invention uses the ground surface height model point cloud data to extract the edge contours of the building and perform regular processing to establish a digital elevation model, and then performs digital differential correction on this basis to generate an orthophoto, which can not only effectively eliminate the orthophoto The sawtooth distortion phenomenon that exists at the edge of the abrupt elevation of the building in the orthophoto image beautifies the orthophoto image and ensures the plane accuracy of the orthophoto image, which greatly promotes the application of UAV low-altitude aerial photogrammetry technology.

Description

Technical field [0001] The invention relates to a method for automatically correcting digital ground elevation models in low-altitude aerial photogrammetry. Background technique [0002] With the development of science and technology, UAV low-altitude aerial photogrammetry technology has been widely used in surveying and mapping industry because of its low cost, fast and flexible, high-resolution images, and low requirements for take-off and landing conditions. It is used to measure houses, elevated highways, etc. The shape and location of the building. The low flying height and low base-to-height ratio of UAVs can easily lead to large projection errors in the images captured by them. For buildings with sudden elevations at the edge points in the vertical direction, the projection errors in the captured images are greater. [0003] The principle of calculating the pixel value of the digital orthophoto map (Digital Orthophoto Map, referred to as DOM) in the prior art is as follows:...

AI Technical Summary

Problems solved by technology

[0008] If the DSM is not processed, the height of the edge of the building is discontinuous, which will lead to obvious jagged deformation and edge blur on the edge of the generated orthophoto, and affect the interpretation and extraction of the target building, reducing the UAV Application Effect of Low Altitude Aerial Photogrammetry Technology

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