Neil,
Neither one is a projection. Both are Datums - national systems of
Latitude and Longitude. Both Datums use the GRS80 ellipsoid of reference,
so in that case they are the same to a novice. However, they are quite
different in use.
A projection is a coordinate system "projected" on a developable surface,
either geometrically or on the complex plane. It is expressed as cartesian
coordinates (X,Y).
A Datum is expressed in Latitude and Longitude such as OSGB36, as used in
the UK.
Clifford J. Mugnier
Chief of Geodesy and
Associate Director,
CENTER FOR GEOINFORMATICS
Department of Civil Engineering
CEBA 3223A
LOUISIANA STATE UNIVERSITY
Baton Rouge, LA 70803
Voice and Facsimile: (225) 578-8536 [Academic]
Voice and Facsimile: (225) 578-4474 [Research]
======================================================
http://www.asprs.org/resources/GRIDS/
http://www.cee.lsu.edu/facultyStaff/mugnier/index.html
======================================================
Hi All
I have imported a .mif file of Australia, which is set by default to a
NAD83 projection. When I try to save it out as its correct GDA94
projection, it just remains in NAD83. Has anyone come across this before?
Are these two projections the same?
Cheers
Neil
---------------------------------------------------------------------
List hosting provided by Directions Magazine | www.directionsmag.com |
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Message number: 17938
