<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif;"><div>Matt,</div><div><br></div><div>Try the GDA Technical Manual [1] p7 for starters.</div><div><br></div><div>This contains a reference and some parameters for Clark 1858 ellipsoid and the Australian National Grid that was often used in conjunction.</div><div><br></div><div>This will give you an authoritative starting point.</div><div><br></div><div>Bruce</div><div><br></div><div>[1] <a href="http://www.icsm.gov.au/gda/gdav2.3.pdf">http://www.icsm.gov.au/gda/gdav2.3.pdf</a> </div><div><br></div><div><br></div><div><br></div><span id="OLK_SRC_BODY_SECTION"><div style="font-family:Calibri; font-size:11pt; text-align:left; color:black; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt"><span style="font-weight:bold">From: </span>Matt Boyd <<a href="mailto:mattslists@gmail.com">mattslists@gmail.com</a>><br><span style="font-weight:bold">Date: </span>Monday, 13 October 2014 11:14<br><span style="font-weight:bold">To: </span>qgis-user <<a href="mailto:qgis-user@lists.osgeo.org">qgis-user@lists.osgeo.org</a>><br><span style="font-weight:bold">Subject: </span>[Qgis-user] Clarke ellipsoid<br></div><div><br></div><blockquote id="MAC_OUTLOOK_ATTRIBUTION_BLOCKQUOTE" style="BORDER-LEFT: #b5c4df 5 solid; PADDING:0 0 0 5; MARGIN:0 0 0 5;"><div dir="ltr">Hi QGISer's
<div>I've some old (early 1960's) that was acquired with what appears to be a clarke ellipsoid. This predates AGD66. It's from Australia, with a central meridian of 141. I've got a scanned image but it's from the middle of a desert and there are no landmarks
to georeference. I've also got a series of lats/longs and XY text files that relate to that data and projection. </div><div>epsg 4008 looks to be about the closest however I'm not sure how accurate this is. Has anyone worked with data like this and how it compares to something like AGD66/GDA94.</div><div><br></div><div>TIA</div><div>Matt</div></div></blockquote></span></body></html>