Debian Proj upstream source notes
---------------------------------

The Debian Proj package comes with both proj4 upstream and additional
datum grids (http://download.osgeo.org/proj/proj-datumgrid-1.4.zip at
the time of this file) in a single package. A note about datum grids you can
find in nad/ directory and datumshifts.shar archive is mandatory.
All those data are public domain, taken and collected from various
US/Canada, France, Switzerland and New Zealand public domain resources.

Most of them are available in ASCII form, and some use a NTv2 binary 
format. The NTv2 format is a documented format used by some tools freely
available by various sources: some of them are binary-only, other
are available in source form. As references about data origins consider
the following:

Australia: http://www.icsm.gov.au/icsm/gda/gdatm/index.html
France: http://www.stjohnspoint.co.uk/gis/france.htm
Canada: http://www.geod.nrcan.gc.ca/tools-outils/ntv2_e.php
Germany: http://crs.bkg.bund.de/crseu/crs/descrtrans/BeTA/de_dhdn2etrs_beta.php
UK: http://lists.maptools.org/pipermail/proj/2006-November/002658.html
New Zealand: http://www.linz.govt.nz/geodetic/software-downloads/index.aspx
Switzerland: http://www.swisstopo.admin.ch/internet/swisstopo/en/home/topics/survey/lv03-lv95/chenyx06/distortion_grids.html

-- Francesco Paolo Lovergine <frankie@debian.org>  Wed Nov 26 10:52:29 CET 2008
