--- In
BoundaryPoint@yahoogroups.com, "Ron McConnell"
<rcmcc@e...> wrote:
>
> I mentioned that I was checking out transformations
> between latitude & longitude in NAD-27 and NAD-83, etc..
> Below is a quote that came up with a google search
> for something like
> "datum transformation nad27 nad83 latitude longitude"
> if I recall correctly.
>
> "Background:
> Downloading GPS data stored in WGS84/NAD83 datum
> and displaying them with GIS data in NAD27 datum
> can result in a 100's of meters in error!"
>
> <www.nps.gov/gis/gps/gps4gis/how2s_byCatagories/>
>
> "Corpscon is one of our favorites...
> US Army Corp of Engineers - Corpscon for Windows...
> uses the US NGS NADCON algorithm"
>
> Free download (9.8MB) from
>
>
>
<
http://www.gisuser.com/index.php?option=com_remository&Ite
mid=105&func=
> fileinfo&parent=category&filecatid=225>
>
> or <http://tinyurl.com/5mfc2>
>
> See also the AKSO (Alaska US National Parks Servive)
> cheatsheet called "CorpsconUse.doc" for instructions (MS
Word)
>
>
<
http://www.nps.gov/gis/gps/aksogps/GenGPSToolKit03/Cheats
heets/Corpscon
> Use.doc>
>
> or <http://tinyurl.com/65lf9>
>
> I've added and tested "Datum Transformations" bookmarks
> for CORPSCON and the cheatsheet to BP.
>
> The letter from Gary Jeffress on legal aspects of maps
> and suggesting lat & long to 3 decimal digits of seconds
> was _very_ interesting. That gives us some indication
> of how well a pro can do using pro gear
> and how to judge some of the web sites and programs
> that spit out many, many digits. Such results
> may (or often may not) be mathematically correct,
> but are meaningless in the real world of measurements.
>
> Starting this week and continuing to the end of the year,
> we will be away from home for 3 days a week many weeks
> and out of internet access. Usually I end up getting
> _way_ behind in email and end up having to delete
> unread most of the many email digests to which I subscribe. :(
> So if anyone has a direct question or comment for me,
> send a direct personal email to my address.
>
> "aletheiak" says,
> "...happily our mathematical needs & challenges
> are ever changing as well as never ending..."
> Wouldn't have it any other way. :)
>
> Have fun.
>
> Cheers, 73,
>
> Ron McC.
> w2iol@a...
>
> Ronald C. McConnell, PhD
>
> WGS-84: N 40º 46' 57.6" +/-0.1" W 74º 41' 22.1" +/-0.1"
> NAD-27: N 40º 46' 57.2" +/-0.1" W 74º 41' 23.5" +/-0.1"
> FN20ps.77GU31 +/-
> V +5058.3438 H +1504.2531 +/-
>
> http://home.earthlink.net/~rcmcc
>
> "Not everything that counts can be measured
> and not everything that can be measured counts"
> - Albert Einstein
>
> Go Hokies!!
okayyy doc
all beautiful
& before you vibrate out of normal range of us
& indeed just to emphasize how much we do appreciate all this
& even assuming you will be too busy
except for a rainy night when you too might really appreciate the
entertainment
we do just happen to have available a recent case study
which could definitely stand
& might actually be improved by
your scrutiny & tech
it is presented more or less in full in
http://groups.yahoo.com/group/BoundaryPoint/message/14915
but first please see
http://www.confluence.org/confluence.php?visitid=8945
& if you need more help sorting all this out
i am sure dave or i will be glad to answer any specifics
&or for the full context
if ever wanted
try a bc search on bcidwa
back to 14817
or perhaps even all the way back to 14557
if you find you cant get enough
& your task in a nutshell
should you decide to accept it
would be to bust the perhaps overconfident prediction i made in
http://groups.yahoo.com/group/BoundaryPoint/message/15002
by somehow improving on my now admittedly naive guess
namely
that the truest available bcidwa is
18 inches due north of the 1909 marker center
plus or minus 6 inches
but in any case
& until we meet again
many thanxxx & vis tecum