Thanks for the response I got..here is a summary...

The question
===========


Hi Everybody,

I have a file of GPS coordinates with lat/long in decimal degrees. I would like to 
convert these to UTM xy coordinates. I have used the projection button but what 
happens is all my points map to one location on top of each other. Is there something 
I am not doing right? I would like to go to UTM Zone 12, CM -111 s.f 0.9996, false e = 
500000, false n =0

Thanks for your help,

Juliana


Replies:
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Hi Juliana

If you open the lat long table first and check the map projection for MAP menu 
then settings this should show LAT LONG.( WGS 84 - see below)

Now use SAVE COPY AS. When the dialog comes up set the projection for the saved 
table to your desired UTM value. Now close all tables and open up the saved 
table. Check the Map Projection again and this should be in your desired values.

I an new to GPS and am keen to learn a lot about it. I think your first file 
should be LAT LONG WGS 84! I hope if this information is wrong someone will 
correct me. The difference will be the spheroid that gets used and I think the 
WGS 84 is the correct one for the values GPS computes. If you do not have the 
correct spheroid for your GPS coordinates you will build in errors when you 
convert to your preferred projection.

Certainly taking this approach in the UK and then further shifting the 
coordinates using the tables from Ordnance Survey I am within 5 metres of their 
MasterMap data with both the �100 Pretec GPS and the �200 Socket bluetooth GPS. 



Cheers,

Bob

---------------------------------
Juliana,

In converting from lat/long to decimal degrees, it sounds as if you need to
reproject the map layer.

You do this not by changing the projection with the button (since the
original map layer maintains the base projection), but by using the "Save
Copy As" feature and then assigning a projection using the "Projection"
button in the "Save As" dialog box.

Call me if you need any more help!

-Ross E. Bagwell
GIS Manager
Universal Access Inc
312-881-4083


--------------------------
Juliana,
 
Have you tried the attached MapInfo tool?

It converts between DMS and decimal degrees (and vice versa)...
 
Maybe if you use this to convert BEFORE you reproject to UTM...
 
:)
 
Ross



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