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<p>Hi Calvin:</p>
<p>An interesting question. Another consideration is the coordinate
system for your project. If it is a projected system, then you
should consider convergence which is the angle between true north
and grid north. In a common example, UTM zone meridians are the
center of each zone which are given an arbitrary easting of
500,000m. If you are converting from magnetic to true north close
to the meridian, then true north will be very close to grid
north. If you are east of the meridian, perhaps close to the
adjacent zone boundary, then grid north and true north will vary
noticeably.</p>
<p>We developed a script for calculating convergence in UTM as I am
unaware of a plugin provides that level of functionality.
Ultimately, it will depend on the coordinate system you are
working in. If you reach out to me privately, I can share the
script with you.</p>
<p>Kirk Schmidt</p>
<p><a class="moz-txt-link-abbreviated" href="mailto:kirk@nortekresources.com">kirk@nortekresources.com</a> <br>
</p>
<div class="moz-cite-prefix">On 5/17/2024 9:15 AM, Jeremy Jackson
via QGIS-User wrote:<br>
</div>
<blockquote type="cite"
cite="mid:6a424880-073d-466c-97ce-88d6654cbdbc@coplanar.net">
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<p><br>
</p>
<div class="moz-cite-prefix">On 2024-05-17 07:00, C Hamilton via
QGIS-User wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CABPxTTrrdJaVENxF+WRBfW23-rvVq4Ktbr-iGz+rJ6juCM-1kA@mail.gmail.com">
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content="text/html; charset=UTF-8">
<div dir="ltr">Phil,
<div><br>
</div>
<div>The Shape Tools plugin has an "Azimuth distance
digitizer" and for what you are talking about an "Azimuth
distance sequence digitizer". With the latter function you
click on a starting location and then give a list of
azimuth, distance sequences. I have used this for old
surveys like this. There is also an declination offset just
in case your surveys were using magnetic north and not true
north. In that case you have to look up what the </div>
</div>
</blockquote>
A related question, what about grid to ground conversions and
vice-versa, are there plugins which support this? Surveys here in
Canada always specify a "combined scale factor", which is tedious
to apply manually to each vertex when digitizing.<br>
<blockquote type="cite"
cite="mid:CABPxTTrrdJaVENxF+WRBfW23-rvVq4Ktbr-iGz+rJ6juCM-1kA@mail.gmail.com">
<div dir="ltr">
<div>declination offset was for your 1880s date.<br>
</div>
<div><br>
</div>
<div>Regards,</div>
<div>Calvin</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Thu, May 16, 2024 at
9:50 PM Philip Ryan via QGIS-User <<a
href="mailto:qgis-user@lists.osgeo.org"
moz-do-not-send="true" class="moz-txt-link-freetext">qgis-user@lists.osgeo.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div class="msg-1476221510151755154">
<div dir="ltr">
<div
style="direction:ltr;text-align:left;text-indent:0px;background-color:rgb(255,255,255);margin:0px;font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Hello,</div>
<div
style="direction:ltr;text-align:left;text-indent:0px;background-color:rgb(255,255,255);margin:0px;font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
I am trying to digitise a series of old gold lease
"portion plans" produced in the 1880s in Australia by
a mining surveyor using a compass and chain. The data
for each gold lease includes a table of 1) compass
bearings in degrees and 2) distance measurements in
links (0.2 m) for each vertex of the lease polygon
(mostly a rectangle or trapezoid but sometimes more
complex). </div>
<div
style="direction:ltr;text-align:left;text-indent:0px;background-color:rgb(255,255,255);margin:0px;font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
The Advance Digitizing Tools would seem to be ideal
for this data except for the angle measure (a) which I
can't input as a compass bearing (0-360 deg). The
current settings with 90 deg E as the zero makes
conversion of compass bearings very tedious.</div>
<div
style="direction:ltr;text-align:left;text-indent:0px;background-color:rgb(255,255,255);margin:0px;font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Is it possible to change the angle variable (a) to a
compass bearing?</div>
<div
style="direction:ltr;text-align:left;text-indent:0px;background-color:rgb(255,255,255);margin:0px;font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Regards,</div>
<div
style="direction:ltr;text-align:left;text-indent:0px;background-color:rgb(255,255,255);margin:0px;font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Phil Ryan</div>
</div>
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<pre class="moz-signature" cols="72">--
Kirk Schmidt, MScF, BScF, RPF
General Manager
Nortek Resource Solutions Inc.
26 Church Road
Sutherlands River, NS
B0K 1W0
Tel (902) 922.3607
Email: <a class="moz-txt-link-abbreviated" href="mailto:kirk@nortekresources.com">kirk@nortekresources.com</a>
Web: <a class="moz-txt-link-abbreviated" href="http://www.nortekresources.com">www.nortekresources.com</a></pre>
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