NASA Shuttle Radar Topography Mission (SRTM3) Global 30 arc-second - National Geospatial Data Asset (NGDA)

The first release of Shuttle Radar Topography Mission (SRTM) data was provided in 1-degree digital elevation model (DEM) tiles from the USGS 2003. The data was released continent by continent, as and when the data was processed by NASA and the USGS. For the United States, data was made available at 1-arc second resolution (approximately 30m at the equator), but for the rest of the world the 1-arc second product is degraded to 3-arc seconds (approximately 90m at the equator). SRTM elevation data has now been released for the entire terrestrial surface, and a Finished product has now been released.航天飞机雷达地形测绘任务（Shuttle Radar Topography Mission，SRTM）的首批数据于2003年由美国地质调查局（USGS）以1度分幅的数字高程模型（Digital Elevation Model，DEM）瓦片形式发布。该数据在由美国国家航空航天局（NASA）与美国地质调查局（USGS）完成处理后，按大洲逐一对外发布。其中美国地区的数据以1角秒分辨率（赤道处约30米）公开提供，而全球其余地区的1角秒产品则被降级为3角秒分辨率（赤道处约90米）。目前SRTM高程数据已覆盖全球全部陆地表面，其最终成品已正式发布。