Google Earth Engine（GEE）——ASTER全球数字高程模型（GDEM）v3-CFANZ编程社区

ASTER全球数字高程模型（GDEM）v3
ASTER GDEM的第一个版本于2009年6月发布，是利用Terra上的ASTER仪器收集的立体对射图像生成的。ASTER GDEM的覆盖范围从北纬83度到南纬83度，包括了地球上99%的陆地。

改进后的GDEM V3增加了更多的立体对，提高了覆盖率，减少了伪影的出现。完善的生产算法提供了更好的空间分辨率，提高了水平和垂直精度。ASTER GDEM V3保持了GeoTIFF格式，以及与V1和V2相同的网格和瓦片结构，具有30米的张贴和1×1度的瓦片。你可以在这里阅读更多关于该产品的用户指南:

https://lpdaac.usgs.gov/documents/434/ASTGTM_User_Guide_V3.pdf

免责声明：该数据集的部分或全部描述借用了作者提供的现有描述。

源数据结构
数据为Geotiff格式，每个文件被分为1x1度的瓦片。为了允许添加单个图像而不是集合输出，将压缩文件解压并生成单个复合tif文件。

NASA/METI/AIST/Japan Spacesystems, and U.S./Japan ASTER Science Team. ASTER Global
Digital Elevation Model V003. 2018, distributed by NASA EOSDIS Land Processes DAAC,
https://doi.org/10.5067/ASTER/ASTGTM.003

Google Earth Engine（GEE）——ASTER全球数字高程模型（GDEM）v3_DEM

代码：

var countries = ee.FeatureCollection("FAO/GAUL/2015/level0"),
    GDEM = ee.Image("projects/sat-io/open-datasets/ASTER/GDEM");

var palettes = require('users/samapriya/utils:palettes');


// Add the elevation to the map.  Play with the visualization tools
// to get a better visualization.
Map.addLayer(GDEM, {}, 'elev', false);

// Use the terrain algorithms to compute a hillshade with 8-bit values.
var shade = ee.Terrain.hillshade(GDEM);
Map.addLayer(shade, {}, 'hillshade', false);

// Create an "ocean" variable to be used for cartographic purposes
var ocean = GDEM.lte(0);
Map.addLayer(ocean.mask(ocean), {palette:'000022'}, 'ocean', false);

// Use these visualization parameters, customized by location.
var visParams = {min: 1, max: 3000, palette: palettes.extra.blkred};

// Create a mosaic of the ocean and the elevation data
var visualized = ee.ImageCollection([
  // Mask the elevation to get only land
  GDEM.mask(ocean.not()).visualize(visParams), 
  // Use the ocean mask directly to display ocean.
  ocean.mask(ocean).visualize({palette:'000022'})
]).mosaic();

// Note that the visualization image doesn't require visualization parameters.
Map.addLayer(visualized.clip(countries), {}, 'ASTER GDEM');

Sample Code: https://code.earthengine.google.com/?scriptPath=users/sat-io/awesome-gee-catalog-examples:elevation-bathymetry/ASTER-GDEM

License¶

All LP DAAC current data and products acquired through the LP DAAC have no restrictions on reuse, sale, or redistribution. This license can thus be treated similar to a public domain CC0 license. ASTER GDEM Version 3 (ASTGTM V003) was released on August, 5, 2019 and contains no redistribution requirements. The LP DAAC kindly requests that you properly cite the data in your research.

Created by: NASA, METI, AIST, Japan Spacesystems and U.S./Japan ASTER Science Team

Curated in GEE by: Samapriya Roy

Keywords: ASTER, DEM, elevation, remote sensing