Gale Crater Stereo CTX DTMs + Orthoimages

CTX Stereo Digital Terrain Models (DTMS) and Orthorectified Images

See Readme for full details.

These data products were produced by Peter Grindrod and Joel Davis at the Natural History Museum, London.

They are shared here in an "as is" format. Please read the following information carefully.

Data Structure

The file "Index_ DTMs.xlsx" gives the image numbers and DTM filenames.

Data Sets

The exact products for each image pair include:

- 20 m/px DTM

- 20 m/px FOM (Figure of Merit - see below)

- 6 m/px orthoimage

Each image has been orthorectified using the relevant DTM. No data have been georeferenced to either another data set in this release, nor another Mars data set. Therefore care should be taken in the first instance in georeferencing as required. Although each DTM is tied to MOLA, there are likely to be some small elevation steps across DTM boundaries as a result of no bundle adjustment across DTMs. Finally, the quality of the DTMs is on the whole good, but noise levels vary – check the FOM and create a hillshade to ensure that each DTM is adequate for required use.

DTM Vertical Precision

The vertical precision of the DTMs can be estimated by using the method outlined in:

- Kirk, R. L., E. Howington-Kraus, B. Redding, D. Galuszka, T. M. Hare, B. A. Archinal, L. A. Soderblom, and J. M. Barrett, (2003), High-resolution topomapping of candidate MER landing sites with Mars Orbiter Camera narrow-angle images, J. Geophys. Res., 108(E12), 8088, doi:10.1029/2003JE002131.

- Kirk, R. L., et al. (2008), Ultrahigh resolution topographic mapping of Mars with MRO HiRISE stereo images: Meter-scale slopes of candidate Phoenix landing sites, J. Geophys. Res., 113, E00A24, doi:10.1029/2007JE003000.

File Format

Each file is available in geotiff format.

Credit

CTX images should be credited "Image: NASA/JPL-Caltech/MSSS”

Derived DTMs should be credited as "DTM: NASA/JPL-Caltech/MSSS/NHM”, and as follows, if possible

"The stereo DTM processing was carried out at the Natural History Museum, London"

Figure of Merit (FOM) explanation

If present, the FOM is a data product produced by the BAE Systems SOCET SET software, which is essentially a measure of the quality of the DTM.

The numerical value of each pixel corresponds to either how the pixel was generated or the confidence in the value.