SRTM data are organized into individual rasterized cells, or tiles, each covering one degree by one degree in latitude and
longitude. Sample spacing for individual data points is either 1 arcsecond, 3 arc-seconds, or 30 arc-seconds, referred to
as SRTM1, SRTM3 and SRTM30, respectively. Since one arc-second at the equator corresponds to roughly 30 meters in horizontal
extent, the SRTM1 and SRTM3 are sometimes referred to as "30 meter" or "90 meter" data. SRTM data were
processed and delivered continent-by-continent and data for each continent are located in a separate directory on this server.
The definitions of the continents are displayed in the figure below and at higher resolution in the file Continent_def.gif.
Edited SRTM1 data for the United States and its territories and possessions are also being released and can be found in the
directory /United_States_1arcsec./ Cells that straddle the border with neighboring countries have been masked with quarter
degree quantization such that data outside the U.S. have the void value. <br /> <br />