[Therion] Surface profile in elevation maps

[Steve Clark]

Martin,

Picking points from GoogleEarth works very well. Thank you for the 
suggestion. I found a very useful tool here :

http://www.gpsvisualizer.com/elevation

By simply importing the .kml file of the cave centreline data 
(lat-long), this online tool will create a list of coordinates including 
the ground altitude at each point from one of it's datasets. Very easy 
to use and copy-paste the data back into therion as fixed stations. I 
imagine it would be easy to extract a full DTM surface grid using this tool.

Bruce,

Your suggestion worked great. It is a little odd when used in extended 
projection, but seems correct in elevation projection.

I do have a bit of a problem in exporting to pdf, and this may be me 
missing something more fundamental in how survey/maps are structured and 
therion builds up the plot :

When I just plot centreline data, I can see cave centreline and the new 
ground surface centreline for the complete cave length. When I include a 
single cave scrap, I no longer see any centreline data outside this 
single scrap. Is there a way to over-ride this behaviour or 
alternatively how should I structure my survey/map objects to avoid this?

Thanks to all for your help,

Steve