<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><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;}
@font-face
{font-family:Papyrus;
panose-1:3 7 5 2 6 5 2 3 2 5;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
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]--></head><body lang=EN-AU link="#0563C1" vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal> “and this places it off the west coast of Ethiopia.?” A familiar issue for many of us with the wrong CRS or reversing the easting and northing. I wasn’t quite sure what the solution for the problem was though. Could you georeference the raster?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>With GPS heights the rule of thumb, handed to me by an old and crusty land surveyor, for GPS’s is vertical error = 2x Horizontal error. The first question is what GPS you are using. In am not sure but Garmin64 is not a precise GPs so you might have an inherent 1-2m error horizontally on a good day which would translates to 2-4m vertically.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The second one is trees. As Nicolas Cadieux noted STRMs are affected by trees but equally so are GPS’s. I think we have converging error factors that would explain the elevation differences.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I am not sure carrying a barometer about is the solution. In practical terms I usually carry GPS, Camera, notebook, Phablet plus a spare power source all of which are getting a bit heavy a barometer might just be too much. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Cheers <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b><span style='font-size:12.0pt;font-family:Papyrus;mso-fareast-language:EN-AU'>Dr Iain Stuart<o:p></o:p></span></b></p><p class=MsoNormal><b><i><span style='font-size:12.0pt;font-family:Papyrus;mso-fareast-language:EN-AU'>JCIS Consultants <o:p></o:p></span></i></b></p><p class=MsoNormal><span style='mso-fareast-language:EN-AU'>P.O. Box 2397<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-AU'>Burwood North<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-AU'>NSW, 2134<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-AU'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-AU'>(02) 9701 0191<br>(0413) 380116 (m)<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>