Survey with laser instruments

[Graham Mullan]

Thank you to all who have answered. that was a very interesting read. A 
few points:

I did indeed mean instruments such as Wookey says, SAP and relatively 
cheap laser disto. It is interesting to see a description of the 
relative accuracy of all these instruments.

Andy, I have no idea what sort of instrument you used for your surface 
survey in Austria but I don't quite understand what you mean by the 
"angular accuracy being very small". Can you re-phrase?

Pat, there is a statistical problem about errors. Certainly the fewer 
readings you take, the fewer "blunders" that should be made, but, then 
again, they may be harder to detect. however, assuming that "errors" as 
opposed to "blunders" are truly random then the greater number of shots 
the greater the likelihood that the errors will cancel out. if the error 
is, however, systematic, that is they tend in one direction rather than 
another, then the accumulated error will be lower if there are fewer legs.

I agree that it is important that time is taken to use any instrument 
properly, to understand how to maximise accuracy.

I wholeheartedly agree that laser distos make the sketcher's job far 
easier and much more accurate. A great improvement.

Graham