ETOPO1/ETOPO2/ETOPO5/TerrainBase Data Sets
ETOPO1 is the current global topographic data set. You can Thin it to get equivalents to ETOPO2 (25% of the file size) or ETOPO5 (4% of the file size). Even ETOPO5 cannot be displayed on screen with full resolution , so you only need ETOPO1 when zooming in significantly.
ETOPO5/2/1, unlike GTOPO30/Globe/DTED0/SRTM30, has elevation data over both land and water. GTOPO30 covers only the continents. The marine data primarily comes from radar altimeters.
ETOPO5 was initially generated by the US Navy from a digital data base of land and sea-floor elevations on a 5-minute latitude/longitude grid. The resolution of the gridded data varied from true 5-minute for the ocean floors, the U.S.A., Europe, Japan, and Australia to 1 degree in data-deficient parts of Asia, South America, northern Canada, and Africa. Data sources are as follows: Ocean Areas: U.S. Naval Oceanographic Office; U.S.A., W. Europe, Japan/Korea: U.S. Defense Mapping Agency; Australia: Bureau of Mineral Resources, Australia; New Zealand: Department of Industrial and Scientific Research, New Zealand; balance of world land masses: U.S. Navy Fleet Numerical Oceanographic Center. ETOPO5 had 4320x2160 data values, one for each five minutes of latitude and longitude, for a total of 9,331,200 points or 18,662,400 bytes. Data values are in whole meters, representing the elevation of the CENTER of each cell.
Center ETOPO on Pacific
Comparison of 30" global DEMs which will have slightly better resolution on land.
Last revision 12/29/2017