Decimal Degrees would imply that your map was 'unprojected' or rather in the plate carree projection. MapInfo would call this Lat/Long and maybe WGS84.
 
However, it is very unlikely anyone would have ever published a map in this form, so I suspect that Transverse Mercator is more like it. In which case your co-ords would be metres in the projection counted from the projection origin. This would normally be the intersection of the central meridian and the equator, which would agree with your large y values. In most cases map makers would use a false origin (i.e. an x and y shift or offset) in order to make the co-ordinates on the map more user-friendly.
 
regards
 
Tim
 

Dr Tim Rideout
Director
 
Visit XYZ at the Cape Town International Book Fair, June 2006, Frankfurt Book Fair, Oct 2006, Intergeo Munich Oct 2006 or IMTA World in Singapore, Nov 2006.
 
The XYZ Digital Map Company
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From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ericson, Tim
Sent: 09 March 2006 17:35
To: [email protected]
Subject: [MI-L] Question on Projection of TOPO 7.5 min Maps

 

I’m trying to import TOPO maps (MRSid format) into MapInfo.

 

The sources FAQs  say that the projection is “Decimal Degrees” – I’m not sure what that is telling me – relative to the projection Options in MI…

 

The metadata mentions UTM Zone 13 (NAD 27)

 

When I use that projection I get locations such as

 

           X Cord     459,082.52

           Y Cord   3,913,385.49

 

 

Which really makes NO sense to me!

 

I open the MRSid into OpenEV and I get the same type of X Y Cordinates.

 

 

 

I’m sure that I’m making a mistake somewhere!!!!  Have you any suggestion?

 

 

Thanks!

 

Tim Ericson

Network Engineer

Qwest Communications

On loan to Harris Corp FAA Telecom Improvement Project

 

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