A Global DEM of Rhea: Almost Complete, My most recent 'monster project' Options

[Bjorn Jonsson]

I'm now getting very close to finishing a near-global DEM of Rhea using stereo images. This has been a true 'monster project' involving 71 image pairs, a significant amount of software improvements and some impatience .

This has been an extremely interesting project but the results are fairly interesting. I have 'discovered' a highly degraded impact basin similar in size to Tirawa - it's not obvious in the source images. There are some interesting features near Tirawa's antipode that I think are real but I'm not completely convinced - if real they may or may not be associated with Tirawa's formation. I will post more details plus some crater depth measurements once I finish the DEM sometime in April.

There are a few frustrating gaps in the DEM, the biggest one in the north polar region for obvious reasons and another one near longitude 0. The latter may get filled following a nontargeted flyby in June 2010 (assuming Rhea gets imaged the way I want ).

I will probably be posting a flyover movie before mid-April and possibly a rotation movie as well. Meanwhile I'm posting two test renders:





The first one is from 3100 km from Rhea's center and has a FOV of 30°. The other one is from an altitude of 340 km and has a 45° FOV. I didn't drape a texture map over the DEM. The DEM is global so this wouldn't look realistic. The first one looks fairly realistic even though it is very obvious that it is computer generated. The second one reveals that the resolution of the DEM is several times lower than the resolution of the source images - they typically have a resolution of ~1 km/pixel.

And as previously noted: There's more to come in the not too distant future. And an interesting decision: Which satellite to do next.