Test file hawaii-c.tar.gz is originally from the U. S. Geologic Survey
1:250,000-scale Digital Elevation Models (DEM) archive.
Original URI: http://dds.cr.usgs.gov/pub/data/DEM/250/H/hawaii-c.gz

Retrieved January 13, 2012

Background from http://dds.cr.usgs.gov/pub/data/DEM/250/250DEMREADME1.txt

A digital elevation model (DEM) consists of an array of elevations for
ground positions that are usually at regularly spaced intervals.

The 1-degree DEM provides coverage in 1- by 1-degree blocks and is
available for all of the contiguous United States, Hawaii, and most of Alaska.

The 1-degree DEM consists of a regular array of elevations referenced
horizontally on the geographic coordinate (latitude/longitude) system
of the World Geodetic System 1984 Datum.  Elevation data located on the
degree lines (all four sides) correspond with the same profiles on
adjoining DEM blocks.

Elevations are in meters relative to mean sea level.  Spacing of the
elevations along and between each profile is 3 arc-seconds with 1,201
elevations per profile.  The only exceptions are DEMs in Alaska, where
the spacing and number of elevations per profile varies depending on the
latitudinal location of the DEM.  Latitudes between 50 and 70 degrees
north have spacings at 6 arc-seconds with 601 elevations per profile
and latitudes greater than 70 degrees north have spacings at 9
arc-seconds with 401 elevations per profile.

Local files:

hawaii-c.tar.bz2 - hawaii-c.gz re-compressed using the tar/bzip2 compression method.

hawaii-c-control.tar.bz2 is the dsp primitive produced by a working run of dem-g,
used as control with which to test the result.  The .g file is not compared because
it is almost guaranteed to be different due to the inclusion of the dsp file path
embedded in the .g database.  Compressed with tar/bzip2
