%0 Dataset
%T The SRTM DEM dataset in the Black River Basin
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/902c7afe-5fcf-4b29-b435-0b9c890c388c
%W NCDC
%R 10.12072/ncdc.westdc.db3672.2023
%A Heihe project data management center
%K Digital elevation model;Mosaic;SRTM;DEM
%X SRTM (Shuttle Radar topology mission) is a global 3D graphics data project jointly established by NASA and National Geospatial Intelligence Agency (NGA). In February 2000, the SRTM system of the U.S. space shuttle Endeavour collected radar image data between 60 ° N and 57 ° s, and obtained radar image data covering more than 80% of the world's land surface. After more than two years of processing, a digital terrain elevation model is made. This data set includes two kinds of data: SRTM sub map and mosaic map of Heihe River Basin, in which the sub map is the data of SRTM version 4, which is compiled by cgiar-csi (International Tropical Agriculture Center, Http://srtm.csi.cgiar.org/) processing, compared with the previous versions, has greatly improved: 1) a large number of interpolation algorithms are used, 2) more auxiliary DEM data are used to fill in the white spots and blank areas, 3) compared with the data of the third version, the image element is offset by one-half. Mosaic is obtained by splicing on the basis of sub graphs. The sub maps include srtm～04, SRTM ᦉ 05, SRTM ᦉ 04, SRTM ᦉ 57 ᦉ 054 maps. The data are 16 digit values representing the elevation value (- / + / 32767 m), the maximum positive elevation is 9000 m, and the negative elevation is 12000 m below sea level. Empty data is identified with - 32767. A file is divided into 24 lines (- 60 to 60 degrees) and 72 columns (- 180 to 180 degrees) every 5 degrees of longitude and latitude.