Application Of Unmanned Aerial Vehicle(UAV) In Rural Land Survey

UAV low altitude aerial photography system is a space data acquisition systemintegrating new technologies such as UAV,photography,remote sensing,communication,3S and inertial navigation.It has the characteristics of high mobility,high integration,high resolution and low cost,and can quickly acquire high resolution images.It has become a satellite remote sensing and manned aerospace photography.Effective supplementary means of photogrammetry.It has been successfully applied in the production of large-scale digital line mapping,Digital Orthophoto Image and digital elevation model and other 4D products.It makes it possible to quickly acquire geospatial elements such as environment,resources,land and so on.It has become one of the important technical means to acquire geospatial data information.At present,UAV has been widely used in land survey,contractual management rights and large-scale topographic mapping.Based on the data acquisition and processing of UAV low-altitude photogrammetry system and the cadastral survey project of new town in Wudalianchi Scenic Area Nature Reserve,Heilongjiang Province,this paper systematically studies the principle of UAV low-altitude photogrammetry system,the acquisition of image data,the data processing and the accuracy evaluation of data results.Technology,using UAV aerial photography technology to obtain raw image data,using Pix4 D aerial survey data processing software to encrypt the air-to-air three to generate Digital Orthophoto Image DOM,combining with the survey data obtained by traditional surveying and mapping means such as total station,the accuracy evaluation is obtained.Through the analysis of the accuracy comparison of experimental data,the resolution of 0.03 m is verified.The aerial photographic data of UAV can not satisfy the accuracy requirement of one kind of boundary points in Cadastral survey,but it can fully satisfy the accuracy requirement of two kinds of boundary points and objects in Cadastral survey.At the same time,the image data obtained by UAV aerial photography can be used as the working base map of cadastral survey.The main contents of this paper include the following parts:(1)The principle and composition of UAV low-altitude photogrammetry system are expounded.The main technologies of UAV low-altitude photogrammetry,such as data acquisition method,flow chart,route design,quality inspection,are studied.At the same time,the main attentions of foreign image data aerial photography and image control point acquisition and layout are studied.(2)Studying the data processing technology of UAV aerial photography,forming a complete set of data processing methods.Using Pix4 D software,the POS(positioning and attitude determination system)is processed,the exterior orientation elements are inversely calculated,the point cloud is generated,the space-three encryption is carried out,the DEM and DSM are made by point cloud encryption,and then the DSM(digital surface model)is processed.DOM(digital orthophoto)is generated by digital differential correction.(3)The acquisition method of 0.03 m resolution UAV aerial photography data in Wudalianchi Scenic Spot of the test area is studied.The DOM and field measured 1:500 scale DLG results are superimposed and compared,and the plane point-to-point error of 0.063 m accuracy of UAV low-altitude aerial photography system is obtained.Through accuracy evaluation and time-to-hour ratio,the plane point-to-point error of coordinate point accuracy of UAV low-altitude aerial photography system The coordinate data obtained by UAV low altitude photogrammetry technology can be used as the result of 1:500 cadastral survey and the second class boundary points,and the image map can be used as the base map of cadastral survey and ownership survey.