Terrain
# 简介
地形(Terrain)提供描述地形坡度、坡向、山体阴影等特征的算法集合。
# aspect
根据DEM数据进行坡向计算,获取坡向影像。
函数 | 返回值 |
---|---|
aspect(self) | Image |
# 示例
geometry = pie.Geometry.Polygon([[
[
120.14843750000063,
41.78937765652833
],
[
120.78564453125199,
41.97750297114209
],
[
120.77465820312324,
41.53494144776468
],
[
120.33520507812159,
41.56782841155561
],
[
120.14843750000063,
41.78937765652833
]
]], None)
# 计算地形坡向
id1 = "LC08/01/T1/LC08_121031_20170117"
imageB = pie.Image(id1).select('B1')
ter = pie.Terrain(imageB)
print('aspect:',ter.aspect().getInfo())
# hillShade
通过数字高程模型计算山体阴影。
函数 | 返回值 |
---|---|
hillShade(input,altitude,azimuth,zScaleFactor) | Image |
参数 | 类型 | 说明 |
---|---|---|
input | Image | 输入高程影像,单位为米 |
altitude | Float, default: 45 | 太阳高度角,单位为度 |
azimuth | Float, default: 315 | 太阳方位角,单位为度 |
zScaleFactor | Z因子, default: 1 | 垂直方向因子,当垂直(或高程)方向与水平方向坐标单位不同时,可以使用z因子调整垂直(或高程)方向的测量单位 |
# 示例
Map = pie.Map()
image_dem = pie.ImageCollection('DEM/ASTGTM_003').first().select("dem")
imageShade = pie.Terrain.hillShade(image_dem,45,315,8)
visParam = {
'opacity':0.5,
'classify':'-11000,-8000,-7000,-6000,-5000,-4000,-3000,-2000,-1000,-500,-200,-100,-50,0,50,100,250,500,750,1000,1250,1500,1750,2000,2500,3000,3500,4000,4500,5000,5500,6000,8800',
'palette':'145999,1b76cc,1f86e6,26aaea,36b6eb,4dc0eb,60cfeb,77daef,b0dfef,d1e5ee,dce6f0,e1e7f2,dee6f1,43c370,44b772,52c88e,' +'6fc993,7ecb97,acd2ad,d4c97a,d0bc59,d3b146,c78f3c,c3812d,c5762b,b95322,ae4621,ba6e78,bc8fa9,c7aac6,dbcdde,fffcff'}
image_out = pie.Image(255).subtract(imageShade).abs()
Map.addLayer(image_dem,visParam,'dem')
Map
# slope
根据DEM数据进行坡度计算,获取以度为单位的坡度影像。
函数 | 返回值 |
---|---|
split(self) | Image |
# 示例
geometry = pie.Geometry.Polygon([[
[
120.14843750000063,
41.78937765652833
],
[
120.78564453125199,
41.97750297114209
],
[
120.77465820312324,
41.53494144776468
],
[
120.33520507812159,
41.56782841155561
],
[
120.14843750000063,
41.78937765652833
]
]], None)
# 计算地形坡度
id1 = "LC08/01/T1/LC08_121031_20170117"
imageB = pie.Image(id1).select('B1')
ter = pie.Terrain(imageB)
print('slope:',ter.slope().getInfo())
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上次更新: 2022/05/25, 07:37:39