Gerald I. Evenden gevenden at capecod.net
Mon Apr 3 10:27:55 EDT 2000

In my reply I was not considering an interactive usage.  Mechanisms
in this case are infinitely varied as is the use of the PROJ library.
For example, an alternative is to display the global zone map and
require a click on the requested zone.  I might add that the irregular
zones of Scandinavia negate merely focusing the zone screen on
the region of interest unless the magnification was sufficiently

Jerry Evenden and the low riders: Katie and Daisy-Mae
gevenden at capecod.net  http://www.capecod.net/~gevenden
-----Original Message-----
From: Craig Bruce <csbruce at cubewerx.com>
To: osrs-proj at remotesensing.org <osrs-proj at remotesensing.org>
Date: Monday, April 03, 2000 9:27 AM
Subject: Re: [OSRS-PROJ] MGRS?

>"Gerald I. Evenden" <gevenden at capecod.net> wrote:
>> Regarding "automatic" UTM by only specifying longitude, there is
>> a technical problem: UTM zones allow a half degree overlap (actually
>> 3.5 degrees wide) so geographic coordinates laying in this region
>> are ambiguous as to which zone to apply.  Secondly, this ambiguity
>> always exists for those points on the even 6 degrees.
>I'm not sure what other applications might exist for a "automatic" UTM, but
>the main one that I can think of is an interactive browser situation where
>someone is viewing a rendered image on the screen.  In this situation,
>it makes perfect sense for the browser system to automatically select
>the UTM zone (and hemisphere) to use based on the center point of the
>display window.  Of course, the [a] calculation of the UTM zone of the
>center point of the image given its lat/lon is so simple that it doesn't
>really need to be part of the Proj library.

OSRS PRoject PROJ Discussion List
To Subscribe: send a message to majordomo at remotesensing.org with 'subscribe osrs-proj' in the body
To Unsubscribe: send a message to majordomo at remotesensing.org with 'unsubscribe osrs-proj' in the body
To Report Problems: send a message to owner-osrs-proj at remotesensing.org

More information about the Proj mailing list