Subject: Re: [BoundaryPoint] Re: Visit to BCIDWA (and 49N 117W)<br/>
Date: Jul 28, 2004 @ 02:05<br/>
Author: Dave Patton [DCP] (&quot;Dave Patton [DCP]&quot; &lt;dpatton@...&gt;)<br/>
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<div id="ygrps-yiv-2132004940">At 09:27 AM 2004/07/27, aletheiak wrote:<br/>
<blockquote><span title="ireply"> &gt;--- In <a rel="nofollow" target="_blank" href="mailto:BoundaryPoint@yahoogroups.com">BoundaryPoint@yahoogroups.com</a>, &quot;Dave Patton [DCP]&quot;<br/>
&gt;&lt;dpatton@c...&gt; wrote:<br/>
&gt; &gt; &gt; &gt; I&#39;ve posted the narrative and photos detailing my<br/>
&gt; &gt; &gt; &gt; recent visit to the British Columbia/Idaho/Washington<br/>
&gt; &gt; &gt; &gt; (BCIDWA) tripoint and 49N 117W degree confluence on<br/>
&gt; &gt; &gt; &gt; the Degree Confluence Project website:<br/>
&gt; &gt; &gt; &gt;<br/>
&gt; &gt;<br/>
&gt; &gt;<a rel="nofollow" target="_blank" href="http://www.confluence.org/confluence.php?lat=49&lon=-117&visit=4">http://www.confluence.org/confluence.php?lat=49&lon=-117&visit=4</a><br/>
<br/>
&gt;& this double check only substantiates further the hypothetical 2<br/>
&gt;or 3 meter offset<br/>
<br/>
 </span></blockquote>What method/software are you using for your calculations?<br/>
<br/>
<blockquote><span title="ireply"> &gt; &gt; I have sent an email to the IBC asking what version of NAD27<br/>
&gt; &gt; they have used, but haven&#39;t yet received an answer.<br/>
&gt; &gt; I assumed NAD27 CONUS.<br/>
&gt;<br/>
&gt;hm<br/>
&gt;please explain if & how this might affect the accuracy range<br/>
<br/>
 </span></blockquote>Because unless you know the datum used to express<br/>
coordinates, you don&#39;t really know the &quot;exact&quot; location.<br/>
<br/>
There is, for example, a difference in the 3-parameter<br/>
transformation parameters for NAD27 Canada(Alberta/BC)<br/>
and NAD27 CONUS. Whether this has a measurable effect<br/>
on the possible distance between the line connecting<br/>
boundary markers 194 and 195, and BCIDWA, I don&#39;t know.<br/>
<br/>
<br/>
-- <br/>
Dave Patton<br/>
Canadian Coordinator, Degree Confluence Project<br/>
<a rel="nofollow" target="_blank" href="http://www.confluence.org/">http://www.confluence.org/</a><br/>
My website: <a rel="nofollow" target="_blank" href="http://members.shaw.ca/davepatton/">http://members.shaw.ca/davepatton/</a></div>