Research And Realization On Key Technologies Of Radar Defilade Angles Calculation On Large Field And Multi Scales

To calculate the defilade angles of radar is a typical kind of using of visibility analysis in military field. To research on the key technologies in radar defilade angle calculation, especially when the data covers a large battle field and are organized by several data measurements, which means the data number is great, not only can help the military troops to increase its effectiveness in information situation, but also can help to deeper and wider the basic research of GIS on visibility analysis. So, the research on key technologies is of great value in theory and practice.In this paper, technologies on two different scales of data and algorithms had been researched and realized.On data scale, the algorithm to generate regular DEM data with contour line was introduced, regarding the important characteristic lines of terrains. Considering that the data will be highly frequently scheduled, and the data size would be large, the Pyramid Model was introduced in this paper. DEM data was organized and managed with Quad-Tree structure. Moreover, the way, or the algorithm to change DEM data of traditional partition mode to Quad-Tree structure mode was given.On algorithm scale, the calculation of radar defilade angle in battle field was divided into three modes, which are result-first model, precision-first model and balance model, in all the three ones the data could be scheduled automatically with the multi-scale data. LOS algorithm, as one common visibility analysis algorithm, suffers the disadvantage because of its great amount of calculating, during which quite a part working is redundancy. In this paper, the calculation characteristics of LOS algorithm in discrete computing circumstance were discovered. Considering that two nearby detection directions share some common DEM grid points if they form a little angle, the matrix called"Advanced Matrix"was introduced, thus the LOS algorithm was improved efficiently. As a result, the redundant calculation was avoided remarkably, and the calculation efficiency was highly improved.Based on those above, taking the contour lines on serial scales of 1:1,000,000, 1:250,000, 1:50,000 and so on as basic data, the DEM data were generated and re-organized with the way of Quad-Tree Model. The advanced LOS algorithm was used to do the calculation of radar defilade angles in battle field automatically.