  The datum of Digital Elevation Model of Venus, provided there, derived from raster
data of Global Topography Data Record of Magellan mission, which distributed by Planetary 
Data System (PDS) of NASA. Base resolution of the datum is 45/1024°.
  The datum presented here generally in form of .ZRS-files (stands Zipped Raster Set),
which is proprietary compressed format of author of the datum. Separated files of the datum
are in hierarchical and multi-resolution relation for optimization of speed and appearance 
upon using in Spatial Aspect Viewer and Spatial Aspect Explorer software products of author.
The datum was prepared by re-projecting original data in sinusoidal projection to cylindrical
projection, using linear interpolation along longitude direction.
  Also the datum contents set of spatial regions covered quadrangles of Venus.

See site of author: www.runspect.com for more details.
Copyright (c) 2011-2016 Yuri Feldman
