GETECH World topography geotiffs
As part of GETECH’s global gravity and magnetic data compilation projects, the company has generated a Digital Elevation Model (DEM) of the world. The sources of the data for this model include station elevation data from compilation projects, additional digitised topography maps and gtopo30 data onshore with etopo5 data and SEASAT derived bathymetry offshore.
A 2 minute grid of the global DEM has been generated and converted into a Geotiff suitable for use as an image in your GIS project. a selection of geotiff images have been created using different colour tables. These images are available for download and are royalty-free although we would ask you to reference GETECH if they are to be used in commercial products or for advertising purposes. The digital grid that was used to generate these images can be purchased directly from GETECH.
The original geotiff images were 245Mbytes in size and have therefore been provided in compressed format.
Option 1: ECW format, which is Earth Resource Mapping’s Enhanced Compression Wavelet format. The extension needed to view these images in ArcView together with a range of other software filters/converters are available at no cost from the ERMapper website. http://www.ermapper.com
Option 2: MrSID format, which is LizardTech’s Multi Resolution Seamless Image Database wavelet based encoded image compression format. ArcView 3.2 and 8.1 versions are provided with an extension for viewing MrSID images. Additional free image viewers and browser plug-ins can be found at the LizardTech website. http://www.lizardtech.com. NOTE: There are two files associated with this format and both have been zipped into one file
 wtopo_atlas1 |
 wtopo_atlas2 |
 wtopo_colour1 |
 wtopo_colour2 |
 wtopo_colour3 |
 wtopo_colour4 |
 wtopo_colour5 |
 wtopo_col2_pastel |
 wtopo_mono1 |
 wtopo_mono2 |
GTOPO30 geotiffs
Data from GTOPO30 which is a 30 second grid of onshore topography only, has also been gridded and converted into a series of geotiff tiled images. These images have only been generated using the “atlas” colour table and can be downloaded by selecting the appropriate tile below. Each tile is available in either MrSID or ECW format.
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
|
 |
 |
All images available for download are provided in unprojected, linear lat-long format.
If you require the images in a specific projection please contact GETECH and we can provide you with a quote to generate a geotiff in your chosen projection.