Precision Analysis And Application Research Of UAV Tilt Photogrammetry In Large Scale Topographic Map

"Fourteenth Five-Year Plan" has listed "Real Scene 3D China" as the key research direction of the basic surveying and mapping plan.The oblique photogrammetry technology has been rapidly developed with its special advantages,and has become a very important measurement method in the measurement industry.High market value and application value.Multiple sets of images captured by oblique photogrammetry have richer texture information,which can realize the construction of a real-world 3D model,making the 3D model a data-bearing form of photogrammetry.Extracting landform information through the 3D model and drawing the topographic map becomes A new mapping method has been developed.This method of drawing topographic maps greatly improves production efficiency,reduces labor costs,and has high practical value in surveying and mapping production.The digitization process of the three-dimensional model has extremely high requirements on model accuracy and digital information collection accuracy.This paper combined with engineering practice data and referenced a large number of relevant domestic and foreign literatures,carried out the UAV tilt photogrammetry experiment:with the help of MapMatrix 3D software,the accuracy of UAV tilt photography aerial triangulation was analyzed,and with the help of various software,the tilt photography was analyzed.The accuracy of the measured dense point cloud data in the calculation of earthwork volume.The main content of the thesis research includes the following three parts:(1)The technical theory of the UAV low-altitude digital photogrammetry system and the composition of the UAV low-altitude digital photogrammetry system are introduced in detail.The key technologies of tilt photogrammetry are sparse matching,aerial triangulation,dense matching,and the construction of triangulation.Five key technical processes,including texture mapping,were introduced and analyzed in detail.(2)The main sources of error in 3D modeling accuracy of tilt photogrammetry are theoretically analyzed,a specific experimental plan is designed,a tilt photogrammetry experiment is carried out,and the accuracy of the experimental data is analyzed.The results show that there are no people in hilly areas The precision of the camera's tilt photogrammetry and aerial triangulation meet the requirements of the precision index of 1:500 3D model production:the error in the orientation point plane is 0.069m,less than the limit difference 0.13m,the error in the elevation is 0.12m,less than the limit difference 0.2m;The error in the plane of the inspection point is 0.128m,less than the limit difference of 0.175m,and the error in the elevation is 0.131 m,less than the limit difference of 0.28m;(3)The relative error of the fill and excavation results obtained by using different software to calculate the point cloud data of traditional earthwork measurement can be up to 12.33%.In contrast,the calculation of the fill and excavation method using the method of extracting dense point clouds by using a three-dimensional model constructed by tilting photogrammetry The maximum relative error is only 2.64%,the result is more accurate and reliable,this tilt photogrammetry has better application value and practical significance.