The Accuracy Analysis Of The Large-scale Topographic Map Of The UAV Aerial Photography System

UAV aerial survey system is equipped with UAV sensor equipment,general with digital camera,to obtain data in the work area outside the industry and processing of flight data to obtain the digital elevation model(DEM),digital orthophoto map(DOM)digital mapping(DLG)and digital three-dimensional model and other products.Compared with traditional aerial photography system,Airspace application of UAV aerial survey system is relatively simple,It's no airport required and it needs smaller restrictions on the flight site.The restrictions on cloud cover are small and high resolution images can be obtained with low flying height.The system is easy to operate,and the operation period is low and it can effectively make up for the lack of conventional aerial survey means.It has a wide application prospect in the acquisition of spatial geographic information,especially for large scale topographic maps.At present,the UAV aerial photography production 4D products have the following two ways.One is the UAV vertical photography production of DEM,DOM,DRG and wearing glasses to produce digital topographic map.Another way is to make a digital model of the UAV's oblique photogrammetry.On this basis,the topographic map can be drawn,which can be used for the production of digital topographic map without wearing glasses.In this paper we introduce two ways of making topographic map by aerial photogrammetry.Taking the fixed wing unmanned aerial vehicle(UAV)vertical photography and unmanned aerial vehicle tilt photography as the research object.This paper systematically expounds the composition of UAV aerial photography system and the characteristics of UAV aerial photography system.In this paper,the key technologies of UAV large scale topographic map and the factors affecting the accuracy of large scale topographic map are analyzed and the data processing flow of two kinds of aerial photogrammetry and the working flow of topographic map are discussed in detail.Then take two experiments as an example.The accuracy and precision of the DOM and DLG generated by the data obtained from the fixed wing UAV and the production of the topographic map based on the unmanned aerial vehicle tilt photogrammetry are studied and analyzed.There are five main contents of this paper included:(1)The composition,function and principle of the UAV aerial photography system are described in detail and UAV flight platform system,unmanned aerial vehicle flight control system,unmanned aerial vehicle(UAV)mission equipment and data transmission system.The data acquisition process of UAV aerial photography system is summarized.(2)The paper makes a systematic and deep research on the factors that affect the accuracy of unmanned aerial vehicle(UAV)aerial photography based on the process of making large scale topographic map by the UAV aerial photography system.And this paper summarizes the factors that affect the accuracy of UAV aerial mapping,and makes a detailed analysis and discussion of the above factors.(3)Taking Wuding County as an example,this paper introduces the detailed process of UAV data processing by SVSUAV software and the process and method of making topographic map in MapMatrix software vector mapping module.The digital topographic map of the area is generated,and the accuracy of the topographic map is verified(4)Taking Anning District as an example,this paper introduces in detail the process of UAV's oblique photography and the method and process of using Smart3DCapture software to carry out the internal data processing.The digital terrain model was produced by the method of making topographic map by using DP-Modeler software,and the digital topographic map of the experimental area was made.The accuracy can be studied and analyzed through the inspection of some inspection points.(5)This paper presents a grid network algorithm to improve the accuracy of the elevation in view of the poor precision of the topographic map produced by the oblique photography of the UAV in the vegetation coverage area and applied in the test area.The elevation accuracy of topographic map is improved greatly.