How to deal with LRUD data?

[John Halleck]

On Tue, 15 Feb 2005, Martin Sluka wrote:

> Date: Tue, 15 Feb 2005 10:01:29 +0100
> From: Martin Sluka <martinsluka at mac.com>
> To: survex at survex.com
> Subject: Re: How to deal with LRUD data?
> 
> At 08:13 -0500 14.2.2005, Philip Balister wrote:
> *******************************************
> 
> >1) LRUD is a station attribute, not a shot attribute. So the LRUD data
> >is unique to the station.
> 
> There is very common situation in 3D modeling of cave one needs two 
> different LRUD sets on one station - typicaly if the point is just at 
> beginning of small passage going from large room. Which LRUD is 
> correct in such a case - the LRUD 0.5 0.0 0.6 0.0 or LRUD 8 15 22 1 

  In the LBCC data format we used "/" to mark transitions at points.

  For the case you give we would have had:

       LRUD 0.5/8 0.0/15 0.6/22 0.0/1

  Although it was more common to see just one /ed.
 
  Of course, that was 25 years ago...  amazing to see how much
  progress has been made in the mean time. :)

> ???
 
> One may solve this by several "dirty" tricks - "zero shots", dividing 
> of shots if 3D modeling, ... - bit this is not very correct from the 
> of view point of theory of surveying.
 
  I think you mean theory of modeling.
  
> So the LRUD should not be ONLY the station attribute, but the 
> attribute of shot too - in that case you may use two sets of LRUD for 
> one point, each one connected to different shot, or you may use LRUD 
> not only in the points but in any place on shot (the laser disto is 
> very helpfull in such situation).

  Here I think you've hit the nail on the head as to what the issue is.
  But that's my personal opinion.

> Martin Sluka
> -- 
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