LRUD in Survex

Mike McCombe
Wed, 1 Aug 2001 22:35:41 +0100

----- Original Message -----
From: "David Doolin" <>
To: "Olly Betts" <>
Cc: <>
Sent: Wednesday, August 01, 2001 3:37 PM
Subject: Re: LRUD in Survex

> On Wed, 1 Aug 2001, Olly Betts wrote:
> > On Wed, Aug 01, 2001 at 07:01:35PM +1000, Mike Lake wrote:
> > > On Tue, Jul 31, 2001 at 03:25:23AM +0100, Olly Betts wrote:
> > > > On Thu, Jul 19, 2001 at 09:46:45PM +0100, Peter Wilton-Jones wrote:
> > > > > Is there any plans to implement [LRUD data] into survex? It may be
> > > > > you intend to try and put it into Spud?? Is this a thaught.
> > >
> > > One problem I see is that there seems to be no concensus on the format
> > > LRUD data. Some users have just one set of 4 LRUD data points per
> > > others have two sets; one set "looking into the station" and another
> > > "looking out of the station".
> > > Certainly makes it difficult for programmers.

I'm sure we had this same debate a few years ago, which seems to me to say
that (a) we haven't made much progress and (b) it's still important to

> >
> > There are various problems like this, but as Wookey pointed out to me -
> > an implementation which only accepted a subset of what people actually
> > record is better than simply declaring the problem to be too hard.  We
> > look at what other packages that allow LRUD can handle, and come up with
> > useful model.
To be complete, I guess one should measure LRUD dimensions at each end of a
survey leg perpendicular to the leg itself. I don't suppose anyone does this
though. Realistically, anything would be better than nothing.
> So I wrote an extensive comment on this last night, then did not
> send it because I did not want to become embroiled in yet another
> lrud dispute...
> Succinctly, I think the whole lrud format debate is Stupid because cave
> maps are not accurate enough that it matters.  Thus, when mapping,
> whatever format people want it in is Fine By Me.  Life is too
> short to argue about it.

It still helps to know passage size and makes it much quicker to get from a
line survey to a finished product.

> This is similar to long running disputes in geology about how to
> take orientation data, such as strikes, dips, dip directions, etc.
> Some people really care about this, and get really worked up about
> The Right Way To Do It (Yawn).
> In that case, it was faster to implement all three methods of
> recording data than to argue about relative merits of one form
> over another.
At this rate it'll take another five years to narrow it down to three
alternatives. Can't someone make a bold decisision and just do it?
All the best,
Mike McCombe