This page contains links to the stereo-derived topography that we have produced from the Magellan stereo data.
Using a fully automated process, we have processed all of the left-left stereo data collected by Magellan to generate topography for ~20% of the planet. The details of the processing are described in the following reference, which we request that you cite if you use the data in your research:
Herrick, R. R., D. L. Stahlke, and V. L. Sharpton, Fine-scale Venusian topography from Magellan stereo data, EOS, Transaction, American Geophysical Union, 93, No. 12, 125-126, 2012. http://www.agu.org/journals/eo/v093/i012/2012EO120002/2012EO120002_brr.pdf#anchor (link only works for AGU members, requires login)
If you really want specifics on the details of the tie-point
generation procedure, Dan Stahlke describes in detail the algorithms in
The basic processing stream involved using an iterative, weighted, cross-correlation algorithm to determine match points in FMAP (75 m/pixel) mosaics to determine relative elevations. These data were combined with Magellan altimetry, in the form of the GTDR mosaics, with complementary high-pass/low-pass filters to produce absolute elevations. The final data product has a horizontal resolution of ~1-2 km and a vertical resolution of ~100 m. The data can be downloaded at the following link:
There is a README file in that directory that will explain all the file naming conventions. Included are printable PDF maps of the data and a number of intermediate processing products.
In addition to the global maps, there are also regional DEMs from previously processed data that were previously incorporated into research articles on Venusian impact craters. These data were processed using the old Magellan Stereo Toolkit that Vexcel corporation produced for the Magellan project. The DEMs were produced by first obtaining match points through an automated algorithm (a precursor algorithm to the one used in the fully automated process above), followed by manual editing (which was sometimes extensive). Details of the processing are given in the following reference:
Herrick, R. R., and V. L. Sharpton, Implications from stereo-derived topography of Venusian impact craters, J. Geophys. Res., 105, 20,245-20,262, 2000.
In my opinion, the manual editing gets the details of crater interiors just a bit better than the fully automated data, but the later-generation automated algorithm we used above does much better with everything exterior to the crater's ejecta blanket. The processing used for these earlier DEMs does not integrate the GTDR data into the solution, and you should not trust the absolute elevations, but only the relative elevations. The crater DEMs can be found here, along with a README file that I encourage you to read:
If you use the individual crater DEMs in your research, the appropriate reference to cite is the following:
Herrick, R. R., and M. E. Rumpf, The resurfacing histories of Venusian impact craters, J. Geophys. Res 116, E02004, doi:10.1029/2010JE003722, 2011.
If you have any questions about these data sets, please email me at firstname.lastname@example.org.
Page last updated on March 26, 2012.