  The datum of Digital Elevation Model of South Pole of Mercury, provided there, derived from 
refactored data of Mercury Double Imaging System (MDIS) DEM, version 1 of MESSENGER mission, 
which was prepared by USGS, and distributed by Planetary Data System (PDS) of NASA. The 
refactoring was based on images from Narrow Angle Camera (NAC) and Wide Angle Camera (WAC) 
of the MDIS. Base resolution of the datum is about 665m, but accuracy is much less than for 
500m-resolution DEM of other Pole from Mercury Laser Altimeter (MLA) instrument, due principal 
physical constrains of the refactoring. The data uses Polar Stereographic Projection with true 
scale latitude of -90°.
  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.
  Also the datum contents sparse set of spatial regions covering main features of 
South Pole of Mercury.

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