This data contains abundant topographic, geomorphic and hydrological information within the five Central Asian countries, which can intuitively show the topographic and geomorphic characteristics of the region. Through DEM, a large number of surface morphology information can be extracted, such as slope, aspect, water system, etc. SRTM The 90 meter resolution elevation data comes from CIAT, the data time is 2000, SRTM data adopts WGS84 ellipsoid projection, after the pretreatment and processing of the original download data by the staff of the unit, the 90 meter DEM data set (srtm90m_ca) of five Central Asian countries is obtained, the altitude value of the data is - 227-7050 meters, the spatial data is - 32768, the DEM data format is img grid image, and the horizontal accuracy is The data range is 45 ° - 108 ° E and 32 ° - 56 ° n.
The 90 meter resolution elevation data of SRTM (Shuttle Radar Topography Mission) are jointly measured by NASA and NIMA. The amount of radar image data acquired by SRTM system is about 9.8 trillion bytes. After more than two years of data processing, a digital terrain elevation model (DEM) is made, which is the current SRTM3 terrain product data.
Preprocessing: open DEM elevation data with arcmap10.2 software, and get DEM data of normal elevation value (- 227-7050m) through grid calculation and re classification calculation, and then get the data through cutting the border of five Central Asian countries. DEM rendering map processing: the DEM data after preprocessing is used to generate mountain shadow data (zfactor = 5), and the mountain shadow data and DEM data are superposed to generate DEM rendering map. The rendering image can be reprocessed by users according to their own needs.
All the processing procedures did not destroy the data, and completely retained the attribute information of the original data. The production of rendering diagram only lets users see the fineness of data without adding other elements. The resolution of this data is 90m, and it can be used with the digital elevation data products with the resolution of 30m.
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CSTR:11738.11.ncdc.nieer.2020.1462
10.12072/ncdc.nieer.db3139.2023