Research On Coordinate Positioning Method Of Shell Falling Point Based On Single Camera And DEM

As monocular vision based positioning method uses only one camera,the method has the characteristics of wide measurement scope and simply structure,and does not involve the features matching process required by binocular stereo vision positing method which usually has to use two cameras.For range shell falling point positing system at range which features wide field of vision,ultra-distance and complex terrain,this article proposes the shell falling point calculation method which is based on single camera and Digital Elevation Model.By using this method,in-depth information of shell falling point can be obtained based on camera linear imaging model and interpolation approximation of digital elevation model.Only a single camera is required to calculate the position of shell falling point without the need of moving camera or processing of several images.The method is simple and allows fast calculation and wide application.Based on site conditions,the author conducts simulation analysis by using the proposed positioning calculation method as well as experiments.As the site measurement results show,eccentricity measurement error is less than 1% when the field width of monitored scope is 300 m.The results prove that the positioning calculation method proposed by the article can meet the requirements of shell falling point coordinate calculation and thus has practical value.Contents of the article include:1.Background and significance of the proposal.The article looks at the current study of monocular vision principle based positioning method,and lists the advantages and disadvantages of two kinds of monocular vision principle based positioning methods.The article proposes research method after considering the application problems of current research work,and introduces the study of the article.2.Introduction of the principle of monocular measurement system: coordinate system as introduced in this article and the conversion between coordinate systems;the principles of camera imaging linear model and non-linear model;create the system measurement model by considering the application environment of system and linear imaging model.3.Digital Elevation Model based single camera coordinate measurement method.By using two-dimensional image information,the method can calculate the spatial line between the camera and the shell falling point,and determine the searching staring point and step distance on the spatial line based on the distance between camera and bull's eye.After matching the searching point on the line with digital elevation map,the threedimensional coordinate of shell falling point is finally calculated.Analysis and simulation study of the error sources of the system proposed by the article is conducted.4.Design and creation of shell falling point coordinate positioning system.System hardware connection structure and system software design are introduced.The measurement precision of the method proposed is tested by carrying out outfield experiment.As the experimental results show,the method proposed can meet requirements set by the research subject of the shell falling point coordinate measurement.