[sf-lug] geoprocessing help [Re: sf-lug Digest, Vol 42, Issue 10]

[Alex Kleider]

I have found use of UTM (Universal Transverse Mercator projection) rather than Latitude and Longitude to be much more user friendly. Any GPS worth its salt can be set to use either. Instead of dealing with degrees, minutes and seconds, one deals with a metric grid: Canadian topo maps have the grid lines printed on the maps, the USGS released some like this about 15 or more years ago but they didn't catch on; The current American maps have UTM tick marks in the margins so you can draw your own lines. Try it, you'll like it:-)
Steering this thread back to Linux and Open Source: I wish Garmin would release their Topo US and Topo Canada data and the software to interface this data with their GPSs to run under Linux.
cheers,
alex

a_kleider at yahoo.com


--- On Thu, 7/16/09, John Reilly <jr at inconspicuous.org> wrote:

> From: John Reilly <jr at inconspicuous.org>
> Subject: Re: [sf-lug] geoprocessing help [Re: sf-lug Digest, Vol 42, Issue 10]
> To: sf-lug at linuxmafia.com
> Date: Thursday, July 16, 2009, 1:07 PM
> John Reilly wrote:
> > A good place to start looking for geospatial data is
> the USGS and various agencies that use spatial data.
> Another thing that I probably should have mentioned is that
> you should probably look for WGS-84 based data, although I'd
> guess that most lat/long data out there is WGS-84. 
> That is the lat/long co-ordinate system used by GPS. 
> Believe it or not, there are several lat/long systems and
> the same point on earth may have a different lat/long
> depending on the co-ordinate system used.  More info at
> http://en.wikipedia.org/wiki/World_Geodetic_System
> 
> Cheers,
> John
> 
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