Hmmm..... Maybe I am not using the splay flag correctly? Is there
another flag that might be more appropriate?
The reason those stations are flagged as splay is because they do not
contribute to the length of the cave. They are just connecting a side
passage into the rest of the survey. Marking the shots as splay means
they get left out of the total length calculation.
That part of the cave is a big challenge to survey. The main feature
there is a stairwell with steel hand rails on either side. The rails
really mess with the compass measurements. We tried every which way but
could not get a good match between forward and backward compass. I just
have to trust that averaging the shots will get somewhere reasonably
close to correct.
It also is a place where a lower level stream passage (the E series), a
mid-level side passage (the BU series) and the main passage (plain
numbers going up the stairs) all come together.
The survey trips in this part of the cave happened over three years. We
did not know the BU passage existed until someone was just fooling
around climbing over a rail and along a rock shelf full of electric
lights. From the stairs it looks like a shallow alcove. Even the tour
guides who go past there multiple times every day had no idea. Had we
known, we would have left a good tie-in station. As it is - we had to
make due.
An extract from the centerline data file looks like this:
==========================
data normal from to tape compass clino backcompass backclino left
right up down
# Side passage behind the overlook
flags splay
# The next line is the data we actually shot. Getting it to fit right
on the map
# required juggling the numbers a bit, and that is the second line.
# 3 BU1 4.8 345.5 5.3 180.5 -6.3 - - - -
3 BU1 4.0 315.5 5.3 135.5 -6.3 - - - -
BU1 BU2 11.6 53.1 84.4 228.4 -84.9 16.8 2.2 1.1 11.6
flags not splay
BU2 BU3 18.6 152.8 0.5 332.1 -0.7 4.6 0 0.5 5.1
BU3 BU4 20.5 137.1 -1.1 318.1 1.4 10.7 6.8 1.0 2.2
BU4 BU5 18.5 68.6 2.5 248.7 -2.3 4.9 1.9 1.0 0.8
BU5 BU6 11.3 141.7 10.0 323.1 -11.1 0.5 10.6 7.2 2.3
BU6 BU7 7.8 207.0 18.6 27.9 -19.6 12.9 4.4 18.2 2.8
BU7 BU8 6.9 130.3 -48.0 312.4 47.8 3.8 3.7 5.9 0.5
BU8 BU9 8.6 184.0 10.4 3.2 -9.8 6.4 2.6 3.4 3.0
===============
Bill Gee
On 8/15/23 17:10, Tarquin Wilton-Jones via Therion wrote:
On 15/08/2023 22:52, Bill Gee wrote:
Looking at the .lox file for Stark Caverns, I see a spike that does not
make any sense. I suspect it might be a blunder in the LRUD data,
perhaps a misplaced decimal point - but I have searched all over the
data and cannot find anything that looks out of line. Besides, the
spike is not horizontal, which you would expect from an LRUD blunder. It
goes up at about a 20 degree angle.
Take a look at the file at
https://campercaver.net/MiscFiles/StarkCaverns.lox
Possibly unrelated to the problem, but ...
Several legs are created with a splay, when it looks like they should
have been a leg or a duplicate.
BU1 to BU2 (where the problem is)
G13 to Z1
B1 to B1a
AB1 and AB2
A5 to R1
12 and 14
These can cause issues, because splays are legs are different things,
and you could confuse Therion when it tries to generate walls. It is
supposed to use actual splays for that, but not duplicates. Because you
are calling them splays, Therion tries to use them to work out where the
walls are, and generates a wall where the LRUD data conflicts with what
you have called a splay. So it tries to join the wall it drew at a
station, with the wall you told it is somewhere else in the LRUD data. I
can understand if it does so with a crazy spike, though it is usually
better at handling inconsistent data.
I would need to see the source data to debug further, since I cannot see
what any of the LRUD data looks like.
Cheers
Tarquin
_______________________________________________
Therion mailing list
Therion@speleo.sk
https://mailman.speleo.sk/listinfo/therion
_______________________________________________
Therion mailing list
Therion@speleo.sk
https://mailman.speleo.sk/listinfo/therion
