Research On Geometric Correction Of UAV Image

With the development of Aviation, navigation and digital sensor technology, remote sensing image has become an important source of earth observation. The UAV (Unmanned Aerial Vehicle) remote sensing has advantages of obvious flexibility, maneuvering, high efficiency, low cost and the ability to improve the status of the lack of high resolution remote sensing data in cloudy and misty areas effectively, and thus make it be broadly applied in the field of management of land and mineral resources and disaster prevention, rapid acquisition of space information and topographic map update. However, since the original remote sensing image has multiple kinds of geometric distortion, it must be corrected to certain precision before application. The study of fast and high precision geometric rectification method thus has important meaning.This dissertation first introduces the composition of UAV remote sensing system, analyzes the planning parameter setting of UVA flight route. It carries out distortion correction for the obtained images after analyzing the distortion type digital camera lens. It analyse the conventional geometric correction method based on the analysis of UAV image distortion causes. Because control point selection of the locally-weighted-fitting technique is not flexible enough, it improves the locally-weighted-fitting technique by using control circle to regulate its local corrected region and adding auxiliary control point to cover the area. The locally-weighted-fitting technique improved can be more adequate and reasonable use of local information, has stronger adaptability for the distribution of control points, and can effectively improve the accuracy of the image geometric correction.(1) Based on the analysis of the UAV operational parameters, it obtain the relationship among parameters, then set up these parameters. The UAV remote sensing coordinate system and flight attitude angles are analyzed, And it test是the quality of the UAV image from the image overlap and flight attitude and other aspects.(2) Through the analysis of the distortion of cameras, the distortion of UAV images is corrected by the system distortion model which is adjusted by the beam method of additional parameters, the quality of UAV images is improved effectively, provides a good data source for image geometric correction.(3) Through the analysis of the common geometric correction methods, It propose an improved locally-weighted-fitting technique. By using geometric correction contrast analysis experiment, it can be more adequate and reasonable use of local information, has stronger adaptability for the distribution of control points, and can effectively improve the accuracy of the image geometric correction.(4) After testing the single point positioning accuracy of fine corrected image, through adding geometric deformation test, it evaluates the UAV image correction accuracy from the multi angle.