  The vector map layers data, provided there, originated from HYDRO1k database published 
by U.S. Geological Survey's (USGS) EROS Data Center in form of E00-files. The content of 
the database was developed from raster data of GTOPO30 project by a sophisticated analyze, 
after remapping the original data to Lambert Asimuthal Equal Area projection.
  Only stream-lines layer presented here, remapped back to Cylindrical (i.e. Longitude/Latitude) 
projection. The datum presented here generally in form of .VML-files (stands Vector Map Layer), 
which is proprietary compressed format of author of the datum. Layers of the datum additionally 
augmented with Level Of Details (LOD) attribute "_LOD" for optimized appearance through using 
in LOD-policy feature of Spatial Aspect Explorer software product of author. Also the data 
was undergoing vector quantization filtering with following representation to set of 
respective VML-files of different resolutions for additional optimization of speed and appearance.
 

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