Loop Closures

[Olly Betts]

On Tue, Nov 11, 2014 at 09:00:46PM +0000, Andrew Atkinson wrote:
> My feeling is that the accuracy of both types of instruments is better
> than the methodology that we use to do the survey and that due to being
> able to take reading more easily the DistoX leads to better results, for
> the same speed of survey, without considering the massive improvement to
> diagrams that has been possible by real-time (nearly) plotting in the
> cave and then drawing round it, plus the ability to measure to anything
> with a single click of a button. This has really helped with the
> production of cross sections, that I now do far more regularly, and Andy
> Farrant has commented that they are more useful.

I'd definitely agree there are many additional benefits which are probably
more important than any difference in accuracy - the fixation on how
accurate the newer instruments are was really just because that was the
question raised.

I've not tried a pocket topo underground (I think either you or Becka
offered to lend us one to try in Austria, but the logistics of getting
hold of it defeated us), but certainly being able to measure to almost
anywhere you can hit with a laser beam makes a big difference, and not
having to pick stations you can sight from can simplify surveying in
some passages.

I'm also reminded I was going to sort out cavern to handle multiple
versions of the same leg better - currently it treats each version as a
separate leg, producing a very loopy network which takes a while to
solve.  I've opened a ticket so I don't forget again:

http://trac.survex.com/ticket/46

Cheers,
    Olly