What is DEM SRTM?
The Shuttle Radar Topography Mission (SRTM) provides for the first time a near-global high-resolution digital elevation model (DEM) with great advantages of homogeneous quality and free availability. The last 10 years or so have seen rapid advances in the data processing and applications of SRTM DEM.
What is the difference between SRTM and Aster DEM?
SRTM is considered more accurate as radar beam penetrates into the tree canopy to get accurate topographic measurement, while ASTER gets reflection of sun radiations from tree canopy, which later, photogrammetrically processed to derive DEM.
Which DEM data is best?
The choice of the DEM for elevation mapping is related with the characteristics of the area you have to study. If your study area is non vegetated, the ASTER-DEM is better, because of its original spatial resolution. In fact, ASTER produce a DSM which is affected by vegetation.
Is DEM the same as DTM?
The digital elevation model (DEM) represents the earth’s surface and includes all objects (plants, buildings,…) on it. The digital terrain model (DTM) represents the bare ground surface without any objects.
What is SRTM 90m?
SRTM 90m Digital Elevation Database v4.1. The SRTM digital elevation data, produced by NASA originally, is a major breakthrough in digital mapping of the world, and provides a major advance in the accessibility of high quality elevation data for large portions of the tropics and other areas of the developing world.
What is the resolution of the 90m dem?
The SRTM 90m DEM’s have a resolution of 90m at the equator, and are provided in mosaiced 5 deg x 5 deg tiles for easy download and use.
What is the resolution of the SRTM data?
The SRTM data is available as 3 arc second (approx. 90m resolution) DEMs. A 1 arc second data product was also produced but is not available for all countries. The vertical error of the DEM’s is reported to be less than 16m.
What is the SRTM30 DEM used for?
When no high-resolution auxiliary DEM is available, the 30 second SRTM30 DEM is used as an auxiliary for large voids. For areas with a high-resolution auxiliary DEM: The contours and points surrounding the hole and inside the hole are interpolated to produce a hydrologically sound DEM using the TOPOGRID algorithm in Arc/Info.