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Date: Thu, 25 Mar 1999 21:36:51 -0500 (Eastern Standard Time)
From: Mark Thomas <[log in to unmask]>
Subject: Re: How to obtain Coordinates from a topographical map <fwd>
Sender: Mark Thomas <[log in to unmask]>
> --- Begin Forwarded Message ---
> Date: Wed, 24 Mar 1999 16:45:20 -0500
> From: "William A. Davis" <[log in to unmask]>
> Subject: How to obtain Coordinates from a topographical map
>
> Maybe I can get some advice on this list. I am not a map professional by
> any means. I am interested in preserving the location of the many little
> family cemeteries that are found throughout Carroll County, KY and other
> locations.
>
> I was thinking that one way to do this was to record the latitude and
> longitude coordinates for each cemetery. I don't know much about latitude
> and longitude except that it tells you where a particular location is.
>
> I may someday obtain a GPS device and get the readings at each cemetery,
> but for the moment I am wondering how I can obtain a credible approximate
> reading by cross-referencing the numbers along the borders of a USGS
> topographical map?
>
> I have a topographical map upon which I have marked many of these locations
> and would like to convert them into latitude and longitude numbers.
There are some templates that make this easier. You should look
in catalogs from Forestry Suppliers in Jackson, MS
(www.forestry-suppliers.com), or Ben Meadows in Atlanta (
www.benmeadows.com ). There are templates for Lat/Long, for
determining UTM coordinates, and I suppose they have them for
State Plane coordinates (the three types of tick marks on the
margins of many USGS quads. One that we have, which is marketed
for finding the location of radio towers (but obviously works
for any point on a map), is a little ruler-like device that does
involve drawing lines across your topo, connecting the tick
marks along the edges every 2-1/2 min. You get a grid of nine
2-1/2 by 2-1/2 min rectangles. (library patrons can use a long
straight edge instead of drawing on our maps, or make a
photocopy).
I once worked on some archaeology surveys where the state
required us to fill out a site form where we identified the site
by UTM coordinates (meters). We had a little square clear
plastic overlay template for quad maps that we used somehow to
interpolate the Northing/Easting UTM values. I mention this
because it was actually mandated by a Texas state agency, and
would have covered historic sites such as cemeteries. The
coordinates/projection you use would depend if you want to use
it with other data in that projection in a desktop mapping
program. If that's not your intention, probably
latitude/longitude is easiest for everyone to understand
--probably UTM or State Plane coordinates aren't :)
> I can't tell how to do this just by looking at the map itself. Could
> someone give me some direction?
Just be aware of the different tick marks for different
coordinate systems. A book like "Maps for America" by
the USGS, probably found at most larger libraries, would
probably help. Or "MapUse : reading, analysis, and
interpretation" by Phillip C. Muehrcke. Both good books:
thorough but useful for novices, too.
> The topographical map does have some cemeteries indicated already, but you
> couldn't find them in a web server, I guess because they are not named.
> Have I missed a way to get the server to give the coordinates for these
> unnamed cemeteries?
You probably know that the named cemeteries should be in the
Geographic Names Information Service, at
http://www-nmd.usgs.gov/www/gnis/
The database contains Latitude and Longitude coordinates.
> And a third question: Is the USGS still taking information to update their
> maps? And are they incorporating them into new maps or servers? I thought
> I had heard budget cuts were shutting down the production of further maps.
They're still producing paper maps and I'm sure welcome
corrections. That's not to say they'll update the quads of your
interest any time soon or ever.
> If I still can I'd like to name this maps and get them into the system.
> Would they still take the information on a cemetery that's no longer visable?
I don't think they're interested in something that isn't visible
*at all* anymore. But if there's any evidence at all, I would
think they would be. I believe the names have to be locally
used (e.g., you can't just name them yourself). Most of the
small cemeteries, like family plots or graveyards near old
churches, I don't think are usually named on topo quads, are
they? So, they may have a policy about the size or significance
of a landmark before identifying it with a name, even if it does
go by one locally. Anyone know?
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Mark Thomas / Public Documents & Maps / Perkins Library
Duke University / Durham, NC 27708-0177
[log in to unmask] / voice: 919-660-5853 / FAX: 919-684-2855
The train ...
traditional, yet environmentally sound. --Lisa Simpson
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