<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;" class="">Hi Kevin,<div class=""><br class=""></div><div class="">I did that in a quite dirty way :</div><div class=""><ol class="MailOutline"><li class="">from the contour lines, build a DEM that you export in an ArcGIS ASCII format</li><li class="">Pass the ArcGIS format to the Therion format (header to change)</li><li class="">In QGis, drap the contour lines over the DEM</li><li class="">Export the result as an image</li><li class="">add the image in the DEM in the therion format with the bitmap command (see the thbook)</li></ol><div class=""><br class=""></div><div class="">Cheers,</div><div class=""><br class=""></div><div class="">Xav</div><div class=""><br class=""></div><div><blockquote type="cite" class=""><div class="">Le 14 août 2018 à 09:32, kevin dixon via Therion <<a href="mailto:therion@speleo.sk" class="">therion@speleo.sk</a>> a écrit :</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class=""><div class=""><div class=""><div class="">I have randomly distributed surface points from a Post Processed Kinematic GPS survey (accuracy ~10cm) and wish to calculate surface contours. The reason for doing this is to have detailed data for all the shakeholes. Would like to import the contours into Survex/Therion so these can be seen above the cave.<br class=""><br class=""></div>Has anyone else done this and how ?<br class=""><br class=""></div>My current thinking is to use the QGIS Contour tool to generate the contours and then import these into Survex/Therion as elevation strings using some intermediate data format yet to be decided.<br class=""><br class=""></div>Thanks,<br class=""><br class=""></div>Kevin <br class=""></div></div></blockquote></div><br class=""></div></body></html>