1、abcdefghiArcGIS提取坡度坡向的算法(向下為y軸正方向，向右為x軸正方向)三階反距離平方權(quán)差分dz/dx = (c + 2f + i) - (a + 2d + g) / (8 * x_cell_size)dz/dy = (g + 2h + i) - (a + 2b + c) / (8 * y_cell_size)slope_radians = ATAN ( ( dz/dx2 + dz/dy2 ) )slope_degrees = ATAN ( ( dz/dx2 + dz/dy2 ) ) * 57.29578rise_run = ( dz/dx2 + dz/dy2 aspect =

2、57.29578 * atan2 (dz/dy, -dz/dx) 應(yīng)為aspect = 57.29578 * atan2 (-dz/dx,dz/dy) atan2（x_num,y_num）根據(jù)制定的X軸及Y軸坐標值，返回反正切值,(-pi,pi。if aspect 90.0 cell = 360.0 - aspect + 90.0else cell = 90.0 - aspect1.加載ArcTutorSpatial文件夾中的elevation；2.利用Spatial AnalystSurface AnalysisSlope計算elevation數(shù)據(jù)的坡度，為避免求反正切函數(shù)，可選擇Perce

3、nt；3.利用Spatial AnalystSurface AnalysisAspect計算elevation數(shù)據(jù)的坡向；4.利用繪圖工具在數(shù)據(jù)視圖中畫一包含3*3個像元的窗口，將其高程數(shù)據(jù)依次輸入Excel中；5.按照坡度坡向的求取公式求坡度坡向；6.驗證ArcGIS的坡度坡向求取算法。坡度（Percent）=rise_run*100；aspect = 57.29578 * atan2 (-dz/dx,dz/dy)Erdas提取坡度坡向的算法(向上為y軸正方向，向右為x軸正方向)三階不帶權(quán)差分坡度的計算slope (in degrees) = 坡度百分比所以坡度百分比為1200。坡向的提取If x=0 and y=0 then the aspect is flat (coded to 361 degrees).Aspect*180/pi 變?yōu)榛《?.將GRID數(shù)據(jù)轉(zhuǎn)換為elevation1.img；2.利用InterpreterTopographic AnalysisSlope計算elevation1數(shù)據(jù)的坡度，為避免求反正切函數(shù)，可選擇Percent；3.利用InterpreterTopographic AnalysisAspect計算elevation數(shù)據(jù)的坡向；4.利用繪圖工具在數(shù)據(jù)視圖中畫一包含3*3個