[GeoStL] Re: Benchmarks
- From: Dan Henke <thunder_monk@xxxxxxxxx>
- To: geocaching@xxxxxxxxxxxxx
- Date: Fri, 13 Sep 2002 10:16:43 -0700 (PDT)
Rudy,
I used to work for and as a land surveyor many years
ago and coincidentally work at the USGS now. My old
boss at the survey company would not turn in any
reports on BM or Section Crs. found because the
government would not pay him for the work....We
recovered usually both types on each and every job
that we did so in his files their was a tremendous
amount of information that never was passed on. (The
reasoning was stupid because the USGS or NGS or CGS or
whomever did all the work to set out these marks) but
that never phased him......and a lot of private land
surveyors hold the same attitude.
However in most survey offices the position of these
marks is known to within .10 of a inch (at least the
ones that have been found ) and if they go out looking
for them generally they will use the description and
GPS just as we do now.....once it is found however
they will tie it into there control loop for the
survey which ties the location down so close.
So I think that is what was meant by "exact location"
in the last post.
The reason the coords are off so far on most
benchmarks is that they are there solely for elevation
and not position.....there are a few were the position
is much better (such as triangulation stations) in
those both the elevation and horizontal position were
down at the time they were set.
Sorry for the lecture ...Have a great day
Dan (Thunder)
--- Rudy Johnston <rudyjhnstn@xxxxxxxxx> wrote:
> (i.e. surveyors and others who
> > want/need to know exact
> > locations). This is an intersting statement, in
> that, in every instance where I have been successful
> locating a benchmark, only my skills developed
> through
> geocaching have allowed me to find these. Not one
> has
> been within 50ft (some as far away as 125ft) from
> the
> coordinats listed on the benchmark pages. The only
> other time I've experienced this type of error was
> when my GPSR somehow converted to the Irish datum
> rather than the...... oh oh Since the benchmark
> datum is NAD-83 rather that WGS-84 and my trusty
> GPSR
> is set on WGS-84.... No wonder I can't find these
> things! If the two settings are off enough, I get
> to
> retry all those unfound benchmarks. correct?
> txsyank
>
> --- Roger Barnes <rogbarn@xxxxxx> wrote:
> >
> > Paul Konopacki wrote:
> > >
> > > Is the groundspeak benchmark database tied in
> with
> > the
> > > official government database in any way? For
> > instance, if
> > > you find a benchmark and log it at
> geocaching.com,
> > does
> > > that get registered automatically as a
> 'recovery'
> > in some
> > > other database?
> > >
> >
> > No. Two separate things to do. Many only log
> their
> > finds on
> > geocaching. Some take the time and effort to go
> to
> > the NGS site and
> > submit recovery reports. There is no need to do
> > that, but it lets
> > everyone know what is still there. Keep in mind
> > that the NGS doesn't
> > use these markers, they only maintain the database
> > for the commerce of
> > the United States (i.e. surveyors and others who
> > want/need to know exact
> > locations). They are the ones you ultimately help
> > when submitting
> > reports to the NGS.
> >
> > John Kinder wrote:
> > >
> > > I've run across a number of Army Corps of
> > Engineers benchmarks, but I was
> > > never able to find those in a benchmark
> database.
> > Anyone every seen these
> > > cataloged somewhere?
> > >
> >
> > USACE is the most mentioned group of benchmarks by
> > people wanting to
> > know where to find them so they can log them. No
> > one has found an
> > online database. Some suggest that you should
> keep
> > a manual log with
> > pictures if you have them and post it somewhere.
> > Personally, I don't
> > see the benefit of spending the time and effort.
> On
> > the other hand, I
> > haven't found any like that yet.
> >
> > Keep it up!
> >
> > Roger
> >
>
*****************************************************************************
> > Our NEW WebPage! WWW.GeoStL.com
> > Mail List & Archive Info.
> >
>
//www.freelists.org/cgi-bin/list?list_id=geocaching
> > Msg. of the day, "The peacemaking meeting
> scheduled
> > for today has been cancelled due to a conflict."
>
******************************************************************************
>
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! News - Today's headlines
> http://news.yahoo.com
>
*****************************************************************************
> Our NEW WebPage! WWW.GeoStL.com
> Mail List & Archive Info.
>
//www.freelists.org/cgi-bin/list?list_id=geocaching
> Msg. of the day, "The peacemaking meeting scheduled
> for today has been cancelled due to a conflict."
******************************************************************************
__________________________________________________
Do you Yahoo!?
Yahoo! News - Today's headlines
http://news.yahoo.com
*****************************************************************************
Our NEW WebPage! WWW.GeoStL.com
Mail List & Archive Info.
//www.freelists.org/cgi-bin/list?list_id=geocaching
Msg. of the day, "The peacemaking meeting scheduled for today has been
cancelled due to a conflict."
******************************************************************************
Other related posts:
