Three Counties Survey data and relationship to the surface Topography
Several members have been asking about access to the survey data now that we have a PC in the Library area so here goes with an article of a number of ways of looking at the Three Counties surveys and also in relation to the surface topography.
I will try to keep this article as non techy as possible as it is aimed at the not so computer literate of us.
Firstly you need to understand that the survey data has all been processed using "Survex", a computer program developed by Wookey. Survex is an open source cave-surveying software package.
It is designed to be portable and can be run on a variety of platforms, including Linux/Unix, Mac OS X, and Microsoft Windows. It has been installed on the PC upstairs in the Reading Room at the Farm.
The latest version of the Easegill survey is also loaded onto the same PC.
Survex is very powerful cave survey software, and is actively developing into a complete cave visualisation package. It has a sophisticated but easy to use front end.
You can download your version for the type of computer you have from the website.
Once you have the program you will be able to view the survey files of the Three Counties System. All sorts of files are located in the depository maintained by Becka Lawson at:- .
Aven displays processed cave surveys in a window and allows you to manipulate the view. The file needed is the Easegill-Pippikin.3d file from the depository above.
Download this and save it somewhere you can find it again. The .3d files will run in Aven.
The best way to move the cave is with the mouse. I suggest you try each of these out after reading this section to get a feel for how they work.
If you hold down the right button then the cave is dragged when you move the mouse.
If you hold down the left button, then the cave is rotated if you move left or right, and zoomed if you move up and down.
If you hold down Ctrl while dragging with the left mouse button, then the cave rotates and tilts at the same time instead.
If your mouse has a middle button then holding it down and moving the mouse up and down tilts the cave. Moving the mouse left and right has no effect.
What about Google Earth
The cave survey can also be viewed in Goggle Earth using a kml file. KML is a file format used to display geographic data in an Earth browser such as Google Earth.
The Survex data has been converted into .kml or .kmz files that can be run in Google Earth so that you can see where the caves fit in with the surface topography.
I have put the latest .kml files on the Red Rose website at this link along with the latest easegill.3d file that we have. I will try to keep this updated.
1 Install the free Google Earth tool on your computer
2 Double-click on any .kmz file to open it in Google Earth.
3 Right-click (or control-click) on the .kmz layer and select Save As.
4 Use the Save As drop down menu to select .kml format.
It will look like this once you run it in Aven
Part of Lancaster Hole, Gale Garth and Cow Pot area imported into Google Earth