RE: [OpenMap Users] UTM vs. LatLon

Hi Jason

        I'm no expert but i'll give it a go.

        Its due to your projection!.
        If you increase the lattitude the projected longitude will also change.
        
        regards

        Mark
        

-----Original Message-----
From: McIlvain Jason B Contr AFRL/IFSF [mailto:Jason.McIlvain@rl.af.mil]
Sent: 11 December 2003 14:13
To: 'openmap-users@bbn.com'
Subject: [OpenMap Users] UTM vs. LatLon

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All,

I have a value for a lat lon point.

I then convert this value to UTM.

If I convert back to lat lon I always get the original value.

However, If I add meters to the northing dimension of the UTM point and
convert back to lat lon, the latitude increases as it should but the
longitude changes as well.

So my question is: Why does longitude change if you add only northing meters
to a UTM point and convert to lat lon?

All calculations are done in WGS84.

I'm trying to build a UTM based grid layer for OpenMap but the lines appear
slightly rotated because of this delta in longitude. If anyone has a UTM
grid for OpenMap that would also solve my issues.

All help is greatly appreciated.

Jason McIlvain

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