HiRISE

[Michele]

hi guys, first of all , sorry for my pathetic english and (hope not) question 

well, I have read some  threads on this forum how to transport HiRISE DTM on Terragen  but no one seems to work to me.

the new (i think) JP2 .img expecially can be converted ?

thx to all to help an older man

[jo]

Hi Michele,

I don't know how technically inclined you are but you could use the GDAL tools (www.gdal.org) to convert the DTM files into a GeoTIFF. There are some instructions here:

https://isis.astrogeology.usgs.gov/IsisSupport/index.php?action=printpage;topic=2345.0

Look at the the "HiRISE import examples" section.

The JP2 images look like they're colour images, like photos, rather than containing elevations like the DTMs, so they probably won't give the results you're expecting.

All things going to plan you should be able to open the HiRISE DTMs directly in an upcoming version of TG2.

Regards,

Jo

[Michele]

thx jo

When try to convert with GDAL have an error msg

"DTEEC xxxxx_xxxxxx_xxxxx_" does not exist in file system 

[Michele]

GDAL work  now

But have some little problem   

[jo]

Hi Michele,

I was playing with HiRISE DTMs yesterday and you get all sorts of variations of this :-). Do this:

- Go back to the page where you got the DTM. If you can't remember which one it was try a Google search for the DTM file name.
- On the DTM page in the "Image Products" section you'll find a link called "Extras Read me". Click on that.
- There will be something that looks a little like this:

Products are tied to MOLA elevations.
Elevation range for this project:
  VALID_MINIMUM    = -1818.91 m
  VALID_MAXIMUM    = -1150.33 m

These values will change depending on the DTM. The number you're looking for is the VALID_MINIMUM one.
- Load your converted DTM into TG2. Select the Heightfield load node.
- Click the "Add Operator" button and choose "Heightfield adjust vertical".
- In the "Heightfield adjust vertical" settings make sure "Add height" is checked and then enter the VALID_MINIMUM from above into the text field.

That should boost the DTM up to the planet surface. Hopefully that does the trick.

Regards,

Jo