Subject: Re: Visit to BCIDWA (and 49N 117W)<br/>
Date: Aug 01, 2004 @ 19:58<br/>
Author: aletheiak (&quot;aletheiak&quot; &lt;aletheiak@...&gt;)<br/>
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<div id="ygrps-yiv-1832905294">dave <br/>
<br/>
just to sum up now as much as possible<br/>
& then suspend the try until we can do better<br/>
<br/>
<blockquote><span title="ireply"> &gt; &gt;i was able to copy these nad83 coords for the 1909 disk<br/>
&gt; &gt;as presented on the 1998 tablet<br/>
&gt; &gt;nlat 48d59m57s110<br/>
&gt; &gt;wlong 117d01m56s715<br/>
<br/>
&gt; &gt;& tho the bcidwa monument does appear to be situated near <br/>
 </span></blockquote>the<br/>
<blockquote><span title="ireply"> &gt; &gt;middle of the clearcut & therefore nearly smack dab on caus<br/>
&gt; &gt;these coords dont compare well to the nad83 coords for the<br/>
&gt; &gt;neighboring markers published by the ibc<br/>
&gt; <br/>
&gt; The International Boundary Commission(IBC) website has<br/>
&gt; both NAD83 and NAD27 coordinates for the boundary markers.<br/>
&gt; Note that the NAD27 ones are listed as being official, while<br/>
&gt; the NAD83 coordinates have been derived by software.<br/>
&gt; I have sent an email to the IBC asking what version of NAD27<br/>
&gt; they have used, but haven&#39;t yet received an answer.<br/>
&gt; I assumed NAD27 CONUS.<br/>
<br/>
 </span></blockquote>right<br/>
& since no news is good news<br/>
i am even more prepared now than i already was to assume this <br/>
with you too<br/>
<br/>
therefore<br/>
best available ibc coords are as follows<br/>
in nad27 presumably conus<br/>
monument 195<br/>
nlat 48d59m57s42<br/>
wlong 117d01m39s71<br/>
&<br/>
monument 194<br/>
nlat 48d59m56s85<br/>
wlong 117d04m17s79<br/>
<br/>
& <br/>
the coords for the 1909 idwa marker given above<br/>
when converted to nad27 conus <br/>
are <br/>
in fully & equally significant digits<br/>
nlat 48d59m57s36<br/>
wlong 117d01m52s85<br/>
<br/>
<br/>
& so by computation<br/>
the sight line between monuments 194 & 195<br/>
crosses the meridian of the idwa marker at<br/>
nlat 48d59m57s37<br/>
wlong 117d01m52s85 <br/>
also in equally significant nad27 conus<br/>
<br/>
<br/>
& thus happily<br/>
we can forget my earlier rough guesses in the 2 to 3 meter range<br/>
which were problematic anyway in not matching the clearcut well<br/>
as indicated in your pix 6 & 7 <br/>
because <br/>
we can now <br/>
more accurately <br/>
compute <br/>
indeed to the nearest hundredth of a second or whole foot<br/>
that the 1909 idwa disk center stands <br/>
1 foot due south of true bcidwa<br/>
<br/>
that is<br/>
as opposed to 2 feet or no feet due south of it<br/>
<br/>
<br/>
so true bcidwa might fall anywhere from 6 inches to 18 inches <br/>
north of this marker<br/>
<br/>
therefore<br/>
in this case<br/>
if you circled the monument at close range<br/>
as i believe you indicated you actually did<br/>
& specifically passed by just behind it here in your pic<br/>
<a rel="nofollow" target="_blank" href="http://www.confluence.org/photo.php?visitid=8945&pic=2">http://www.confluence.org/photo.php?visitid=8945&pic=2</a><br/>
you couldnt have failed to have made your point class b<br/>
<br/>
so extra congrats are in order effective immediately<br/>
<br/>
but we still wont know more exactly where along these 12 inches <br/>
the tripoint actually lies until the ibc either improves their coords <br/>
to thousandths of a second to match those on the tablet <br/>
or else cleans up the clearcut enough to actually make all 3 <br/>
monuments intervisible<br/>
as i believe they theoretically should be<br/>
<br/>
but it seems we are as complete & accurate as possible for now <br/>
anyway</div>