SRTM DEM data processing

DEM (Digital Elevation Model) is a digital terrain model memperesentasi elevation of the earth's surface. DEM broadly divided into two DSM (Digital Surface Model) and DTM (Digital Terrain Model) if in view of the data acquisition process. There are many sources of data that can produce diantaran DEM SRTM, JERS, and IFSAR.
SRTM image of an image can be obtained for free by downloading. However, keep in perhatiakan bawasannya SRTM image of the right is on the mainland alone. In the sea area of ​​more than zero value encountered that which menjadikann SRTM data on marine areas can not be used for data input. Ideal conditions in the ocean of Regional elevation or height value is TNOL, that comfort is a reference sea level height in the earth's surface.
Excess free SRTM data can be used for various analyzes. However, sometimes the SRTM data are met Patch Missing Data. It was necessary for the correction or removal of the patch of missing data for SRTM data is feasible to use. Selian's original format SRTM data. HGT in which the format is not all GIS software including ArcGIS 9.x can be opened to the need for format conversion of data into geotif.
Application of DEM data is pretty much his DEM data which can be used as input for the creation of digital maps of slope. Selian the DEM data can also be used for field analysis of a region. DEM data are mempersentasikan height field can also be used to create contour maps with notes reolusi vertical DEM must consider that in use.

A. STEP WORK
A. Enable 3dem program by clicking on the desktop of your computer if you do not have please download free at http://www.freedownloadscenter.com/Multimedia_and_Graphics/Video_and_Animation_Tools/3DEM.html "
2. Click on File> Load Terrain> select 'SRTM data'> select the file that you want if / remove paths

3. Click F7 or click the tool 'operation'> Patch Missing Data

4. Then drag the data will be removed patch missing data

5. Box selected areas that would in the patch by using the mouse and press enter


6. So that data can be opened in ArcGIS 9.3, the SRTM data. HGT need to change to the format. Geotif by selecting File> Save GeoTIFF DEM> specify the name of his GeoTiff file (eg: Latihan.tif)

SRTM data processing ON ArcGIS 9.3

7. Activate the ArcGIS program, and then open the exercise files that look just a black box. 2x click on the layer Bali.tif> symbology> select 'classified'> apply

Note: In the SRTM data is only just the right land, land that is not improper

8. Enable extensions "3D Analyst" and "Spatial Analyst" and then click Spatial Analyst> Raster Calculator> Int ([Bali.tif])> evaluate to remove the minus in this case the value of minus -57




9. Once the minimum value of 0 then the DEM data can be used for analysis