Improved Algorithm And Accuracy Analysis Of Topographic Visual View

Spatial analysis is the core content of geographic information system, including the overlay analysis, visibility analysis, spatial analysis, buffer spatial proximity analysis and spatial network analysis. The visibility analysis is an important part, which comprises a point-to-point intervisibility and viewpoint, point to point visibility analysis is the foundation of analyzing visibility.R3 algorithm is to reduce the computational difficulty of each point of the complexity of the algorithm and the reduction in required calculating points.Aiming at solving the disadvantage of R3 algorithm, this paper improved the algorithm, and the accuracy of the algorithm is evaluated. The main research contents are summarized as follows:(1)The analysis of topographic profiles, linear clusters and view the deformation problem and analyzes the advantages and disadvantages of R3 algorithm aim to give a direction for improvement. The main purpose of this paper is to reduce the computational visual field need points are pointed out.(2)According to the terrain feature,this part put forward the improvement of algorithm on R3, the feasibility of the algorithm is verified both theoretically and experimentally. From the results we can see that, the improved algorithm is significantly reduced the calculation points.(3)The key problem of the view is obtained when the viewpoint changes moving within the visual field—when the viewpoint moves from the perspective of changes tiny.Visual field improved algorithm has unique advantages in this field.(4)The precision of the result is the key to the success of the algorithm, this part analyzes the sources of error and eliminates the visual domain theory. The domain error sources are divided into the first class and the second class influence factor, and analyzes the corrections.(5)When rejecting the visual domain other factors, this part analyzes the accuracy of visual field of improved algorithm and R3 algorithm experimentally.Improved R3 view algorithm reduces the computational view needed points and improve the visual rate algorithm. The improved algorithm uses more terrain conditions, broadening the visual field analysis method;As a new assessment method of view accuracy analysis, visual rate provided the precondition for the empirical model.