How to Use Digital Terrain Models (DTMs)

The HiRISE DTM is a 32-bit .IMG format. It is not a disk image file. The .IMG is a PDS standard raster file format.

ArcGIS 10 will open the .IMG file directly, but the nodata value needs to be set manually using the Data Management > Raster toolbox. ArcScene and ArcGlobe may also work, but the resolution takes a hit. See the Planetary GIS support pages for more info.

GDAL (gdal_translate) will convert the .IMG into a geotiff, which may be opened by more types of software. ArcGIS 9.x will read the geotiff created this way. The caveat here is that different versions of GDAL read the mapping keywords in the label differently. See attached gdal_usage_notes.txt for more information about installing and using GDAL.

ENVI and Matlab can also open the files. The ENVI HiRISE Toolkit will read all HiRISE RDR products, including JP2s and the DTM IMG files.

In ISIS 3, the .IMG file can be converted into a cube using pds2isis. JP2 support might be available in ISIS now, but you will probably need to convert our JP2s to ISIS cube format in a two-step process. First run JP2_to_PDS (available here ), then the ISIS program pds2isis. This approach is more for the scientist looking to do analysis on the DTM and orthoimages.

NOTE TO USERS OF BLENDER 2.8
The HiRISE plug-in for Blender 2.8+ no longer works and currently, we do not have an ETA on when this will be updated. We recommend using the previous version of Blender to work with HiRISE DTMs. We apologize for the inconvenience.

FOR PREVIOUS VERSIONS OF BLENDER
Blender 2.7 and earlier has a HiRISE plugin available. (The plugin is already included in the public release of Blender since version 2.5.7.) Blender works on all platforms and is free. Here are some instructions to get you started:

1)Turn on the plugin by going to File > User Preferences > Add-ons. Check the box that says Import/Export: HiRISE DTM Importer.

2) Click the “Save User Settings” button and close the Preferences pane.

3) In Blender, under File, select Import > Import HiRISE Terrain Model.

4) Navigate to the directory where you saved the DTM. Click ONCE on it to select it. Then choose the import option in the left panel that sets the import compression. The options are 2x2 (really slow, not recommended), 6x6, 6x6 fast, 12x12 and 12x12 fast. For the first time, the 12x12 fast is recommended. It may still take a few minutes depending on the power of your computer.

5) You can “drape” any of the browse jpeg images over the DTM (except in some of the polar DTMs, where the scaling might be off), such as the colorized altimetry ..ca.jpg. This is done by setting the material property to be one of those images.


AREOBROWSER
All available HiRISE DTMs can also be explored in 3D, directly in your browser and on mobile, at AreoBrowser.com. The site allows you to easily search DTMs by product name and observation ID, and then sort the results by ID, title, date or vertical range. Color altimetry, anaglyph, and varying detail modes are also available.