Global 30 Arc-Second Elevation (GTOPO30)

GTOPO30 is a global digital elevation model (DEM) with a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer). GTOPO30 was derived from several raster and vector sources of topographic information. For easier distribution, GTOPO30 has been divided into tiles which can be selected from the map shown above. Detailed information on the characteristics of GTOPO30 including the data distribution format, the data sources, production methods, accuracy, and hints for users, is found in the GTOPO30 README file.

GTOPO30 是一款全球数字高程模型（Digital Elevation Model，DEM），其水平网格间距为 30 角秒（约 1 千米）。GTOPO30 源自多套栅格与矢量地形数据源。为便于分发，GTOPO30 已被划分为若干瓦片，用户可通过上方展示的地图进行选择。关于 GTOPO30 的各项特征的详细信息——涵盖数据分发格式、数据源、制作方法、精度参数以及用户使用提示等，均可在 GTOPO30 自述文件（README file）中查阅。