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Archiver > TX-CEMETERIES > 2001-09 > 1000332929


From: "Eldon Sanders" <>
Subject: Re: [TX-Cem] Re: GPS Info
Date: Wed, 12 Sep 2001 17:15:29 -0500
References: <200109120901.f8C91H109223@lists5.rootsweb.com> <3B9F5B69.502D1FAE@summit.net>


Donna, in responding to "the other Donna", I assumed that she wanted an aid
in locating cemeteries that are off the beaten path, or perhaps considered
to be lost. While I use my handheld unit for other purposes, those purposes
have nothing to do with cemeteries, but with my other hobby of amateur
radio.

When I am looking for the location of a cemetery, I go to the GNIS system,
locate the cemetery on a map and record the location in degrees, minutes and
seconds of longitude and latitude. I then embark on my search. Those
cemeteries that are on, or can easily be sighted from the roadway are not a
problem. Those that are off the beaten path and that are unknown to local
residents can be approximated as to their location and I have been
successful in locating a few cemeteries which could be classified in the
"lost category". I have also been unsuccessful in some instances for there
were no landmarks.

The Global Positioning System is a system developed in the Department of
Defense at a cost of some 12 billion dollars. Its use, as designed, could
be used by nations enemical to the United States, therefore, until May 2000
it had an error introduced which degraded its accuracy to +/- 100 meters
horizontally. That meant that if you attended a football game you couldn't
determine if you were in the stadium, or not. On May 2, 2000, the selective
availability (SA-the introduced error) was turned off and the accuracy then
became something on the order of +/- 6 meters horizontally (approximately
20 feet). I have seen recent graphics which indicate an accuracy of
abouit 2.6 meters horizontally.

I have recently had some surveying done on my property which was done
with a surveying system using "Differential GPS". That system is capable of
measurements with an accuracy of 2 centimeters/mile. That is not a
handheld. It is a very sophisticated system with a price tag in excess of
$25,000, not including the truck in which the transmitters and receivers are
mounted. I followed the surveyor and at six corners of my property took a
reading with my ColorTrak. I averaged "errors" of about one second
(approximatley 30 feet). The ColorTrak has a capability of entering 500
user-
entered locations.

For your purposes, there is no economical GPS equipment that will do what
you would like to do. You could spend $1500 on a laptop, $1200 on a Garmin
Street Mapping Unit and still not have anything that would overcome the
accuracy
inherent to the system. There is a tutorial at
http://www.trimble.com/gps/index.html
that I recommend to anyone interested in GPS.

E. Sanders, College Station, TX

----- Original Message -----
From: Donna S. Boyd <>
To: <>
Sent: Wednesday, September 12, 2001 7:56 AM
Subject: [TX-Cem] Re: GPS Info


> Sonny,
>
> Thank you for your response to Donna re: GPS receivers. You said it
> "satisfies my requirements." How complicated are your requirements? I
> don't know if Donna wants them for the same purpose I do, but I want to
> be able to survey a cemetery and give the GPS location for each grave.
> I have gotten varying responses about the accuracy of the less expensive
> devices. If they are only accurate to 25-50 ft., that would be helpful
> but not accomplishing exactly what I want. How accurate is your
> ColorTrak? Would you recommend it for this purpose? How many way
> points does it record? Can the information be downloaded to a PC?
>
> Thanks for your help.
> The other Donna, in Virginia
>
>
> ==== TX-CEMETERIES Mailing List ====
> Locate TX County Records at:
> http://www.tsl.state.tx.us/arc/local/index.html
>



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