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Newsgroups: info.grass.user
Path: zorro.cecer.army.mil!shapiro
From: shapiro at zorro.cecer.army.mil (Michael Shapiro)
Subject: Re: spheroids
Message-ID: <C255zB.8EL at news.cecer.army.mil>
Sender: news at news.cecer.army.mil (Net.Noise owner)
Organization: US Army Corps of Engineers Construction Engineering Research Labs
References: <9302012114.AA19672 at hardy.u.washington.edu>
Date: Mon, 8 Feb 1993 17:59:35 GMT
Lines: 42

In <9302012114.AA19672 at hardy.u.washington.edu> bac at u.washington.edu (Brian Connelly) writes:


>Hello,

>I was wondering if anyone could tell me which UTM spheroids
>were available with GRASS ver. 3.1.  Also, was there a default
>spheroid?

>Thank you,

>Brian

>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Brian Connelly
>College of Forest Resources                  phone:  (206) 543-5506
>University of Washington  AR-10                FAX:  (206) 685-3091
>Seattle, Washington  98195                  e-mail:  bac at hardy.u.washington.edu
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

There were only a handful of commands that used spheroids in GRASS3.1.
For example, the d.where command if run in a UTM database would also
report locations in lat/lon if one of these shperoids was present on the
command line:
   australian, bessel, clark66, clark80, everest, international,
   wgs72, wgs84

Please note that GRASS3.1 and GRASS4.0, as a whole, knew nothing about
projections or spheroids.  All GRASS assumes is that the data is
registerd to a common coordinate system so that overlay operations
work. GRASS did not (and probably won't for the forseeable future)
project "on the fly" - ie it won't allow/expect maps under a location
to be in multiple projections.

GRASS4.1 will have the ability to define a projection for a location
(beside UTM) and copy vector maps to/from one location to another
performing the necessary projections.
-- 


Michael Shapiro U.S. Army CERL
Environmental Division