[Therion] example data-georeferencing

[Bruce]

Dan
Similarly to Martin
I do all my image overlays (topo image, aerial photo, geology, contours,
property boundaries, map gridlines etc) in a standalone GIS package, then
use the result as jpg surface overlay in Therion.  

Therion can then regurgitate it all with the cave included as a stand alone
image, or you can produce geo-referenced cave shapefiles from Therion that
will snap straight into your GIS project without ever having to load the
image into Therion in the first place.  Which is the best way depends on
what you want to do ultimately, and which application you feel most
comfortable using.

If you need a more detailed example than Martin has provided I can pull
together a cut down example in due course.  I appreciate that the hardest
bit is knowing how to organise the Therion data.  After 3 years I am still
having new insights and have no idea if I am doing it well.

Bruce