<HTML><HEAD>
<META content="text/html; charset=utf-8" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 11.00.9600.17239"></HEAD>
<BODY style="FONT: 10pt Segoe UI; MARGIN: 4px 4px 1px" bgColor=#ffffff text=#000000>
<DIV>HI All</DIV>
<DIV> </DIV>
<DIV>Universal Transverse Mercator is a coordinate system (just as with Gauss Conform) and is a special case of the Transverse Mercator Projection. It was designed to stretch the TM projection to the longitudinal limit and spreads the distortion across the 6 degree design extent. </DIV>
<DIV> </DIV>
<DIV>The cylinder wraps around the earth in the Transverse aspect and therefore do not have latitudinal bands (besides the equator which is the natural nortings origin)</DIV>
<DIV> </DIV>
<DIV>I have uploaded a document describing the UTM projection as well as a discussion on distortions. </DIV>
<DIV><A href="https://sites.google.com/site/mapprojections/downloads">https://sites.google.com/site/mapprojections/downloads</A> .The document is called "The UTM projection.doc". </DIV>
<DIV> </DIV>
<DIV>I hope this assists</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>
<DIV><FONT size=1 face=Monospaced></FONT><IMG border=0 src="cid:QWOHEZPYRTYD.IMAGE_2.jpg"><FONT size=1><BR></FONT><FONT size=1 face=Monospaced>=== Email Disclaimer =================================================== “The information contained in this email is confidential and may contain proprietary information. It is meant solely for the intended recipient. Access to this email by anyone else is unauthorised. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted in reliance on this, is prohibited and may be unlawful. No liability or responsibility is accepted if information or data is, for whatever reason corrupted or does not reach its intended recipient. No warranty is given that this email is free of viruses. The views expressed in this email are, unless otherwise stated, those of the author not those of Department of Rural Development and Land Reform or its management. Department of Rural Development and Land Reform reserves the right to monitor, intercept and block email addresses to its users or take any action in accordance with its email use policy”. ==================================================================== </FONT></DIV>>>> Peter Newmarch <newmarch@land-surveyors.com> 2014/08/25 02:08 PM >>><BR>
<DIV class=moz-cite-prefix><FONT face="Times New Roman">Hanlie,<BR><BR>UTM only has Longitudinal bands. Their are no, and have never been, any Latitude bands.<BR><BR>There is distortion on the central meridian of 4cm per 100m, and the same at the 3 degree edges on either side. At 1 1/2 degrees from the central meridian - the scale is 1.<BR><BR>Regards<BR><BR>Peter<BR><BR></FONT><PRE class=moz-signature cols="72">Peter Newmarch
Professional Land Surveyor
4Y GeoInformatics Pty Ltd
Tel : +27 31 5642856
Fax : +27 31 5643074
Mobile : +27 82 5705859
eMail : <A class=moz-txt-link-abbreviated href="mailto:newmarch@land-surveyors.com">newmarch@land-surveyors.com</A> </PRE>On 2014/08/25 12:05 AM, Tim Sutton wrote:<BR></DIV>
<BLOCKQUOTE cite=mid:53FA61BD.1080605@kartoza.com type="cite"><PRE wrap="">-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Hi Hanlie
On 13/08/2014 08:26, Hanlie Pretorius wrote:
</PRE>
<BLOCKQUOTE type="cite"><PRE wrap="">Hi,
I've noticed that GIS packages such as QGIS and libraries such as
PROJ4 (which QGIS uses, I think) don't use the latitude bands in
the UTM grid.
Does anyone know why the full UTM grid with latitude bands is not
implemented? Does it result in any additional distortions as one
moves away from the equator?
I have Googled about this and have not been able to find the
answer.
</PRE></BLOCKQUOTE><PRE wrap="">I guess this is an upstream question for the epsg, gdal and proj4
projects (which we rely on for most of the projection work in QGIS). I
am not aware if it results in additional distortions as you move away
from the equator or if the bands simply provide false northings for
convenience. My limited understanding is that their distortion will
increase as you extend away in the longitudinal direction but not in
the latitudinal.
Regards
Tim
</PRE>
<BLOCKQUOTE type="cite"><PRE wrap="">Thanks Hanlie _______________________________________________
Africa mailing list <A class=moz-txt-link-abbreviated href="mailto:Africa@lists.osgeo.org">Africa@lists.osgeo.org</A> You can UNSUBSCRIBE at
<A class=moz-txt-link-freetext href="http://lists.osgeo.org/mailman/listinfo/africa">http://lists.osgeo.org/mailman/listinfo/africa</A>
</PRE></BLOCKQUOTE><PRE wrap="">- --
-
------------------------------------------------------------------------------------------
Tim Sutton
Visit <A class=moz-txt-link-freetext href="http://kartoza.com/">http://kartoza.com</A> <A class=moz-txt-link-rfc2396E href="http://kartoza.com/"><http://kartoza.com/></A>to find out about open
source:
* Desktop GIS programming services
* Geospatial web development
* GIS Training
* Consulting Services
Skype: timlinux
-
-------------------------------------------------------------------------------------------
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iEYEARECAAYFAlP6Yb0ACgkQqk07qZdiYjfZWgCcCLIPcxPngCuiaSB5q7eB6CIQ
CB0AoLylzPAFLkPuV2v7zwwGy6WzjbNU
=iSaj
-----END PGP SIGNATURE-----
_______________________________________________
Africa mailing list
<A class=moz-txt-link-abbreviated href="mailto:Africa@lists.osgeo.org">Africa@lists.osgeo.org</A>
You can UNSUBSCRIBE at <A class=moz-txt-link-freetext href="http://lists.osgeo.org/mailman/listinfo/africa">http://lists.osgeo.org/mailman/listinfo/africa</A>
</PRE></BLOCKQUOTE><BR></DIV><BR>
<div>
<img border="0" src="cid:ICIOCBHAWOEC.53d6419e.jpg">
<br>
<font size="1">=== Email Disclaimer
===================================================<br>The information
contained in this email is confidential and may contain proprietary
information. It is meant solely for the intended recipient. Access to
this email by anyone else is unauthorised. If you are not the intended
recipient, any disclosure, copying, distribution or any action taken or
omitted in reliance on this, is prohibited and may be unlawful. No
liability or responsibility is accepted if information or data is, for
whatever reason corrupted or does not reach its intended recipient. No
warranty is given that this email is free of viruses. The views
expressed in this email are, unless otherwise stated, those of the
author not those of Department of Rural Development and Land Reform or
its management. Department of Rural Development and Land Reform reserves
the right to monitor, intercept and block email addresses to its users
or take any action in accordance with its email use policy”.
==================================================================<br></font>
</div>
</BODY></HTML>