[GeoStL] Re: Map Datum Question

-
John,

If the coords from the Dept of Interior are in NAD27 format, then YES, you
should change the GPS to that map datum. After they are entered, you can
switch back to WGS84 and the coords will be converted  and displayed in
WGS84 and still lead you to the exact same location.

I think here in the St. Louis area, the differences between NAD27 and WGS 84
are not as great as say, the West coast. I compared the numbers at 270 and
Dorsett and the North difference is about 18' and the West is about 30'.
I've read that in some areas it can be more that a 1000' feet off.


----- Original Message -----
From: "John & Lois Roberts" <goshhawk@xxxxxxxxxxx>
To: "SLAGA" <geocaching@xxxxxxxxxxxxx>
Sent: Friday, February 14, 2003 5:03 PM
Subject: [GeoStL] Map Datum Question


> -
> When I download coordinates from geocaching.com into my GPSr, they are
> entered in WGS84 format. Frequently, I then transfer the coords to a US
Dept
> of Interior Geodetic Survey map in NAD 27 Conus format. Should I change
the
> settings in my GPSr to NAD 27 before the transfer, or does it matter? I
have
> tried it both ways but am not sure if there is any significant difference.
> But,  technically there must be a correct way to do this. Can someone be
of
> help?
>
****************************************************************************
>  Our WebPage!  Http://WWW.GeoStL.com
>  Mail List Info.
>  http://www.freelists.org/cgi-bin/list?list_id=geocaching
>  The SLAGA E-store is closed for image repairs but this is what is there.
> The SLAGA E-store  http://www.cafeshops.com/cp/store.aspx?s=SLAGA
>
****************************************************************************
>
>
>
>

 ****************************************************************************
 Our WebPage!  Http://WWW.GeoStL.com  
 Mail List Info. 
 http://www.freelists.org/cgi-bin/list?list_id=geocaching 
 The SLAGA E-store is closed for image repairs but this is what is there.
The SLAGA E-store  http://www.cafeshops.com/cp/store.aspx?s=SLAGA   
****************************************************************************




Other related posts: