For in-cave surveying I use a Leica Disto D3 to measure distance and inclination, and a Sunto KB14 compass for azimuth. There have been, for some time now, certain ‘home-brew’ options to measure all three required dimensions using [i:6xauqkzh][b:6xauqkzh]just one[/b:6xauqkzh][/i:6xauqkzh] instrument: The Shetland Attack Pony (SAP) from UK is one, and it also automates the transfer of data to a Palm Pilot PDA so there is no need to take a notebook into the cave except for sketching; The ‘Disto X’ is a third-party add-in daughter board for a certain Leica Disto model (A5 I think), which does much the same. Being ‘home-brew’ solutions, these devices suffer from the usual problems of dodgy firmware, lack of technical support, unreliability, etc. Also, I understand that calibration is a pain, and required rather too often.
There [i:6xauqkzh][b:6xauqkzh]are[/b:6xauqkzh][/i:6xauqkzh] commercial units that seem to fit our requirements, though they are expensive. My reservation, apart from the expense, is whether they are rugged enough for the cave environment.
The TruPulse unit is here:
http://www.precisionlasers.com.au/image … lse360.pdf
The Laser Ace unit is here:
http://www.mdl.co.uk/resources/LaserAce … _06_06.pdf
The Laser Ace is perhaps the right choice for us: better accuracy at our usual shot lengths.
If you have 2.5 to 3.0 k$ to spare, I think these would be really good gadgets to try out.
(Thanks to Neil for first sending me the TruPulse links)