Dan,
I don't like to carry extra gear (i.e. gps) with me when I record (as
you know Dan, I carry enough weight with my standard system). So I
log the GPS coordinates when I get home with Topo USA.
I purchased the USGS overlay for the program (for northern cal) that
shows the actual USGS 7.5 quad at certain levels of zoom. When I am
recording somewhere I have a map for (like a national park) I will
mark the disc and track number on the paper map to remind myself where
I was, then I find the DMS coordinates (hours, min, sec) and altitude
when I get home. If possible I usually also describe the area and
direction I was recording in.
All this is dropped into my database. It's close enough for my
purposes. Presumably if I want to convert the location to a different
format (imperial to decimal) it just a matter of a new formula in my
database.
--greg
--- In Dan Dugan <> wrote:
> Bill Rainey, thanks for your reply:
>
> >The other parameter you want to report to the park is the map
> >datum you used. U.S. Topo maps are still commonly NAD 27
> >CONUS (North American Datum ...Continental United States). My
> >impression is at least GPS units sold in the US default to
> >another datum (WGS 84), altho you can set them to convert
> >screen output to NAD27 CONUS or many others.
>
> Huh. A different reference point? They've moved Greenwich, or
> something? How far off are you in the wrong system?
>
> >Consumer GPS units can sometimes produce startlingly bad
> >short term fixes, so a reality check via map software (e.g.,
> >National Geographic's Topo or several others) at the position
> >you are about to report is usually educational.
>
> I have TOPO, and plan to hook up a GPS to it. I'm looking for one
> that's compatible with the Mac (USB) so I don't have to use a
serial
> port dongle thing.
>
> >The dominant GIS software parks use to map location data
> >'expects' decimal degrees as input, though conversion is not a
> >big deal (assuming the datum is known).
>
> Thanks!
>
> -Dan
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