Empirical Study On The Production And Accuracy Of Large Scale Digital Topographic Map Based On UAV

Low-altitude drone photography is a research hotspot of many scholars at home and abroad,and it is an indispensable means to solve problems in the fields of emergency relief,resource monitoring,and urban planning.In recent years,the rapid development of science and technology has helped to speculate on the technological development in the field of painting.Low-altitude photogrammetry is particularly prominent and has achieved many outstanding results.The UAV photogrammetry system is a platform that uses a small aircraft that is not manned as a platform,equipped with high-resolution sensors,quickly and efficiently acquires aerial survey images and video data in low-altitude measurement form,and uses image processing technology to generate DLG,DOM,Digital product maps such as DEM and DRG can be used to generate electronic maps for further processing in digital cities.With the rapid development of aerial photogrammetry positioning theory and technology,more and more new methods have been proposed in actual production research,from the construction of the framework route to the improvement of the algorithm of the regional network adjustment model,and the use of differential POS.Auxiliary space three measurements,etc.These methods and theories have not been sufficiently analyzed and verified for the accuracy effects of digital products such as digital line graph(DLG)and digital ortho model(DOM)generated in the later stage.Based on the actual project,this paper has carried out the following work.Based on the German Inpho software to generate digital product maps and accuracy impact analysis,systematically study the theory and method of low-altitude photogrammetry technology,field control measurement and image acquisition,and methods and figures of image processing Indepth research has been carried out on the production of product drawings and theoretical precision analysis.Comparing the aerial photogrammetry based on the layout route and the aerial photogrammetry of the traditional route layout,it is studied whether the method based on the skeleton route can achieve the reduction of the control point during the operation and can meet the accuracy requirement under the same external conditions.The level of accuracy provided by the post-difference POS data during the adjustment of the auxiliary aerial triangulation is analyzed.At the same time,according to the requirements of the production project,the digital product map DLG and DOM are generated and the mapping accuracy analysis under different terrains is carried out.Through the experiment and research analysis of the above contents,the results show that when the low-altitude photogrammetry is performed,the layout of the frame route is increased,and the rigidity of the model is enhanced.The encryption accuracy of the air three can reach about 0.1 m,and the layout of the control points can be reduced.When the post-difference POS data is used to participate in the regional network adjustment,a good adjustment accuracy can be achieved,and the generated DOM and DLG fully comply with the accuracy standard of 1:1000 large-scale digital mapping.