<html>
<head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<div class="moz-cite-prefix">OK, that sounds like the solution I'm
looking for.<br>
<br>
It sounds like the answer is to draw the lines in one projection
and then transform it to the other, depending upon which
orientation is desired for those lines.<br>
<br>
I hope I have this correct…<br>
<br>
<div class="moz-signature">Cheers . . . . . Springfield Harrison<br>
</div>
<br>
<br>
On 03-Apr-2018 02:46, Kristian Evers wrote:<br>
</div>
<blockquote
cite="mid:2E885BB293AF0448A0181138489E9A0EAECB2551@S000014.PROD.SITAD.DK"
type="cite">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta name="Generator" content="Microsoft Word 15 (filtered
medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:"Times New Roman",serif;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:3.0cm 2.0cm 3.0cm 2.0cm;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"
lang="EN-US">You can use the Mercator projection to digitize
true north lines. It is conformal and thus preserves angles.
The meridian convergence is 0 (that is, true north == grid
north) all over the map. If you then transform those lines
to your chosen CRS you should have a set of lines pointing
towards true north instead of grid north.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"
lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"
lang="EN-US">/Kristian<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"
lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif"
lang="EN-US">Fra:</span></b><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif"
lang="EN-US"> Qgis-user
[<a class="moz-txt-link-freetext" href="mailto:qgis-user-bounces@lists.osgeo.org">mailto:qgis-user-bounces@lists.osgeo.org</a>]
<b>På vegne af </b>Alexandre Ne</span><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif">to<br>
<b>Sendt:</b> 3. april 2018 11:15<br>
<b>Til:</b> Springfield Harrison
<a class="moz-txt-link-rfc2396E" href="mailto:stellargps@gmail.com"><stellargps@gmail.com></a><br>
<b>Cc:</b> qgis-user <a class="moz-txt-link-rfc2396E" href="mailto:qgis-user@lists.osgeo.org"><qgis-user@lists.osgeo.org></a><br>
<b>Emne:</b> Re: [Qgis-user] True North<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Maybe something like this :<o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><a moz-do-not-send="true"
href="https://gis.stackexchange.com/q/115531/6191">https://gis.stackexchange.com/q/115531/6191</a><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt">Alexandre<o:p></o:p></p>
<div>
<div>
<p class="MsoNormal">A ter, 3/04/2018, 10:11, Alexandre
Neto <<a moz-do-not-send="true"
href="mailto:senhor.neto@gmail.com">senhor.neto@gmail.com</a>>
escreveu:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC
1.0pt;padding:0cm 0cm 0cm
6.0pt;margin-left:4.8pt;margin-right:0cm">
<p class="MsoNormal">Ah sorry, <o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">I got lost in translation. You are
right, I was talking about the magnetic north, not the
geodetic one.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Meanwhile, remembering that all
UTM are Transverse Mercator, I don't think there's a
CRS that will solve you question.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">I think you need to use some
formula to convert the grid north measures to true
north according to the CRS, and the latitude and
longitude of the place. <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Alexandre <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><o:p> </o:p></p>
<div>
<div>
<p class="MsoNormal">A ter, 3/04/2018, 09:25,
Springfield Harrison <<a moz-do-not-send="true"
href="mailto:stellargps@gmail.com"
target="_blank">stellargps@gmail.com</a>>
escreveu:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid
#CCCCCC 1.0pt;padding:0cm 0cm 0cm
6.0pt;margin-left:4.8pt;margin-right:0cm">
<p>Alexandre,<o:p></o:p></p>
<p>I believe that true north is actually a constant
oriented towards the North Pole, i e 90 degrees
north latitude. Also where all meridians converge
in the northern hemisphere.<o:p></o:p></p>
<p>The other North orientations are magnetic north
and grid North and these do vary as you suggested.<o:p></o:p></p>
<p>I do need to use a UTM projection but need
bearings to be in degrees true north.<o:p></o:p></p>
<p>Thanks Alexandre...<o:p></o:p></p>
<p>Cheers . . . . . Spring<o:p></o:p></p>
<p>Samsung Tab 4<o:p></o:p></p>
<div>
<p class="MsoNormal">On Apr 2, 2018 4:27 PM,
"Alexandre Neto" <<a moz-do-not-send="true"
href="mailto:senhor.neto@gmail.com"
target="_blank">senhor.neto@gmail.com</a>>
wrote:<o:p></o:p></p>
<blockquote style="border:none;border-left:solid
#CCCCCC 1.0pt;padding:0cm 0cm 0cm
6.0pt;margin-left:4.8pt;margin-right:0cm">
<p class="MsoNormal">AFAIK, true bearing differs
in time and location because of magnetic
declination. So I don't think there is a such
thing as a CRS with true bearings. <o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Assuming you are working
at regional level, find the magnetic
declination for that region and remove it
from your observations. Then draw the
azimuth using the chosen CRS. I think 26910
will work just fine. <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">If you are at a larger
scale, then you may need to use different
magnetic declination values for each
observation. <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">This may help:<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"><a moz-do-not-send="true"
href="https://www.ngdc.noaa.gov/geomag/declination.shtml"
target="_blank">https://www.ngdc.noaa.gov/geomag/declination.shtml</a><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Best Regards, <o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal"
style="margin-bottom:12.0pt">Alexandre Neto <o:p></o:p></p>
<div>
<div>
<p class="MsoNormal">A seg, 2/04/2018,
23:54, Springfield Harrison <<a
moz-do-not-send="true"
href="mailto:stellargps@gmail.com"
target="_blank">stellargps@gmail.com</a>>
escreveu:<o:p></o:p></p>
</div>
<blockquote
style="border:none;border-left:solid
#CCCCCC 1.0pt;padding:0cm 0cm 0cm
6.0pt;margin-left:4.8pt;margin-right:0cm">
<p class="MsoNormal">Hello,<br>
<br>
I am using CRS 26910, NAD83 / UTM zone
10N, and need to draw lines at<br>
exact true bearings. The Advanced
Digitizing Tool seems to do this but<br>
which CRS would I use to ensure that the
bearing is True?<br>
<br>
Thanks very much . . .<br>
<br>
<br>
Cheers . . . . . Springfield Harrison<br>
<br>
<br>
_______________________________________________<br>
Qgis-user mailing list<br>
<a moz-do-not-send="true"
href="mailto:Qgis-user@lists.osgeo.org"
target="_blank">Qgis-user@lists.osgeo.org</a><br>
List info: <a moz-do-not-send="true"
href="https://lists.osgeo.org/mailman/listinfo/qgis-user"
target="_blank">
https://lists.osgeo.org/mailman/listinfo/qgis-user</a><br>
Unsubscribe: <a moz-do-not-send="true"
href="https://lists.osgeo.org/mailman/listinfo/qgis-user"
target="_blank">
https://lists.osgeo.org/mailman/listinfo/qgis-user</a><o:p></o:p></p>
</blockquote>
</div>
</div>
<p class="MsoNormal">-- <o:p></o:p></p>
<div>
<div>
<div>
<p class="MsoNormal">Alexandre Neto<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">---------------------<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">@AlexNetoGeo<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><a
moz-do-not-send="true"
href="http://sigsemgrilhetas.wordpress.com"
target="_blank">http://sigsemgrilhetas.wordpress.com</a><o:p></o:p></p>
</div>
<p class="MsoNormal"><a
moz-do-not-send="true"
href="http://gisunchained.wordpress.com"
target="_blank">http://gisunchained.wordpress.com</a><o:p></o:p></p>
</div>
</div>
</blockquote>
</div>
</blockquote>
</div>
</div>
<p class="MsoNormal">-- <o:p></o:p></p>
<div>
<div>
<div>
<p class="MsoNormal">Alexandre Neto<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">---------------------<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">@AlexNetoGeo<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><a moz-do-not-send="true"
href="http://sigsemgrilhetas.wordpress.com"
target="_blank">http://sigsemgrilhetas.wordpress.com</a><o:p></o:p></p>
</div>
<p class="MsoNormal"><a moz-do-not-send="true"
href="http://gisunchained.wordpress.com"
target="_blank">http://gisunchained.wordpress.com</a><o:p></o:p></p>
</div>
</div>
</blockquote>
</div>
</div>
<p class="MsoNormal">-- <o:p></o:p></p>
<div>
<div>
<div>
<p class="MsoNormal">Alexandre Neto<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">---------------------<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">@AlexNetoGeo<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><a moz-do-not-send="true"
href="http://sigsemgrilhetas.wordpress.com">http://sigsemgrilhetas.wordpress.com</a><o:p></o:p></p>
</div>
<p class="MsoNormal"><a moz-do-not-send="true"
href="http://gisunchained.wordpress.com">http://gisunchained.wordpress.com</a><o:p></o:p></p>
</div>
</div>
</div>
<div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br>
<table style="border-top: 1px solid #D3D4DE;">
<tbody>
<tr>
<td style="width: 55px; padding-top: 13px;"><a
moz-do-not-send="true"
href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient"
target="_blank"><img moz-do-not-send="true"
src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-green-avg-v1.png"
alt="" style="width: 46px; height: 29px;"
height="29" width="46"></a></td>
<td style="width: 470px; padding-top: 12px; color:
#41424e; font-size: 13px; font-family: Arial, Helvetica,
sans-serif; line-height: 18px;">Virus-free. <a
moz-do-not-send="true"
href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient"
target="_blank" style="color: #4453ea;">www.avg.com</a>
</td>
</tr>
</tbody>
</table>
<a moz-do-not-send="true"
href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1"
height="1"> </a></div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
Qgis-user mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Qgis-user@lists.osgeo.org">Qgis-user@lists.osgeo.org</a>
List info: <a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/qgis-user">https://lists.osgeo.org/mailman/listinfo/qgis-user</a>
Unsubscribe: <a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/qgis-user">https://lists.osgeo.org/mailman/listinfo/qgis-user</a></pre>
</blockquote>
<br>
</body>
</html>