Scanning the cables with P50 aug-sept 2020

sept 2020
Links
Intro
p50 laser scanner
datafiles
Table of measurements (by date) with plots
Table of measurements by location.

Related pages:
Cable tensions from aug-sep20 sag surveys
Computing the tension from a sag survey

Updates:

Intro

    Following the 10aug20 failure of tower 4 auxmain north, the 305meter suspension cables were surveyed aug-sept 2020 using the p50 laser scanner (this is also called a sag survey). The platform (tower to platform) and backstay (tower to anchor) were  scanned by  Felix and I. Each set of cables was scanned separately (a set would be T12platform, T4platform, T8backstay, etc..). We scanned  each set multiple times to  see if there was a bias that depended on the scanner location.

The P50 laser scanner

 Accuracy specs are:

 Scanner coordinate system


Datafiles:

       The files from the p50 scanner were input to windows using Leica cyclone software. They were then converted to .las (LASer) files and moved to the linux machines.

Table of measurements

    The table below has an entry for each set of p50 cable measurements.  It contains:

Notes on some of the measurements

sag survey measurements
date
cables
scanner location
Npnts
filesize
link to
file
scanner setup
filename
Notes
Tension plots
200814
t12 backstays
West of  cables by  sband
power supply building.
94,374,489
1.8GB
.las
maxRange:120m
sensitivity: normal
res:1.6mm@10m
t12b_200814.las

(.ps) (.pdf)
200828
t4 backstays
base of tower looking
up at backstays  a little to the
south of the centerline
20,870,664
399MB
.las
maxRange:120m
sensitivity:normal
res:.8mm@10m
t4b_200828_clipped.las


(.ps) (.pdf)
*200828
t4 mains
base of  tower looking
up at mains. a little to the
south of the centerline.
2,401,671
46MB
.las
maxRange:120m
sensitivity:high
res:1.6mm@120m
t4p_200828.las
note1:* did not reach the
platform since we
has 120m maxrange.
redid 200901,200902

(.ps) (.pdf)
200831
t12 mains
visitor center balcony
looking south , a little west
of centerline
15,314,540
293MB
.las
maxRange:270  m
sensitivity:normal
res:.8mm@10m
t12p_200831.las
did not get the end of
the aux cable on the
platform side.
redid 200902,04 from
east and west side.

(.ps) (.pdf)
200901
t4 mains
same location as 200828
12,075,977
231MB
.las maxRange:270m
sensitivity:normal
res:.8mm@10m
t4m_200901.las
did not get the end of
auxmain. redid 200902
from rimwall.

(.ps) (.pdf)
200901
t8 mains
rim wall sw-01. looking
north almost at e/w center
of platform.
18,397,989
351MB
.las maxRange:270m
sensitivity:high
res:.8mm@10m
t8m_200901.las
did not get platform
end of t8auxN (platform
hid). redid from north
side 200903.

(.ps) (.pdf)
200902
t4 mains
rim wall se-01. looking
north almost at e/w center
of platform.
13,009,051
249MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t4m_200902.las
got all cables (since
auxmain4N is gone).

(.ps) (.pdf)
200902
t12 mains
rim wall NW-04. looking
east almost at n/w center
of platform.
15,512,363
296MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t12m_200902.las
shot from west side of
dish to get all of
auxmain12-W.

(.ps) (.pdf)
200903
t8 backstays
below backstay cables
close to top of road.
255,660,850
4.8GB
.las maxRange:120m
sensitivity:high
res:.8mm@10m
t8b_200903.las
very large file because
we did 0-360 in az and
0-90 in elevation.

(.ps) (.pdf)
200904
t12 mains
east side of rim wall looking
west. az=85 at distomat 2.
9,946,295
190MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t12m_200904.las
shot from east side.
Tried to get all of
t12AuxMainE but az
arm blocked some of it.

(.ps) (.pdf)
200904
t12 catwalk
east side of rim wall looking
west. az=85 at distomat 2.
9,946,295 190MB .las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t12m_200904.las same file at t12mains
catwalk
plots

200904
t12 catwalk
mid cable
east side of rim wall looking
west. az=85 at distomat 2.
9,946,295 190MB .las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t12m_200904.las same at t12mains file
this is the cable to the
midpoint of catwalk
catwalk
plots

200915
t12 backstays
from the helipad
1,717,397
33MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t12b_200915_hpad.las
tried t12backstays
from helipad and
base of tower 4 .
.ps) (.pdf)
200915 t12 backstays from the base of tower 4
1,105,543
22MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t12b_200915_t4.las
both were a long shot.

(.ps) (.pdf)
200915 t4 backstays
from the helipad
4,856,766
93MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t4b_200915.las
check if 200828 shot
from under the cables is
biased. (not much)

(.ps) (.pdf)
200915 t8 mains
from nw-05 rim wall looking
south toward cables.
3,087,595
59MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t8m_200915.las
shot from the north side
to get auxmain8N better.

(.ps) (.pdf)
200915
t8 catwalk
from nw-05 rim wall looking
south
3,087,595 59MB .las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t8m_200915.las same file at t8mains
catwalk
plots

200915 t8 backstays
from the base of tower 4
708,129
14MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t8b_200915.las
This was another long
shot

(.ps) (.pdf)
200916
t4 mains
from helipad
4,990,131
96MB
.las maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t4cw_200916.las
got t4mains and t4
catwalk cable in 1 file
(.ps) (.pdf)
200916
t4 catwalk
from helipad
4,990,131
96MB
(see t4m)
maxRange:>1km
sensitivity:normal
res:1.6mm@10m
t4cw_200916.las got t4mains and t4
catwalk cable in 1 file
catwalk
plots

201021
t8 platform
from road at base of tower 8
35,619,092
172MB
.las
maxRange>1km
sensitiviey:normal
res:1.6mm@10m
t8p1km_201021.las
discontinuity at x=0
(el=90deg:overhead)
(.ps) (.pdf)
201021 t8 platform from road at base of tower 8 76,816,381

.las
maxRange>270m
sensitivity:high
res:1.6mm@10m
t8p270m_201021nh.las
discontinuity at x=0
(el=90deg:overhead
(.ps) (.pdf)
201106

T4 Main Cable south Breaks







201111
T4 platform
from west edge of helipad
21539287
(preclipping)
47MB
.las
maxRange>1km
res:1.6mm@10m
t4p_201111.las
i clipped out the bushes
has T4 platform
t12 plat:mainsshadowed
t12 backstays
(.ps) (.pdf)
201111
T4 platform
from east edge of helipad
22241431
(preclipping)
41MB
.las
maxRange>1im
res:1.6mm@10m
t4b_201111.las
clipped out bushes
has:
t4Backstays
t4platform
t12platform(shadowed)
t12backstays
(.ps) (.pdf)
201111
T4 backstays
from east edge of helipad
22241431
(preclipping)
41MB
maxRange>1im
res:1.6mm@10m
t4b_201111.las same file as T4platform
from helipad east
(.ps) (.pdf)
201111 t12backstays
from west edge of helipad 21539287
(preclipping)
47MB
maxRange>1km
res:1.6mm@10m
t4p_201111.las same file as 201111
t4 platform west
(.ps) (.pdf)
201111 t12backstays from east edge of helipad 21539287
(preclipping
47MB
maxRange>1km
res:1.6mm@10m
t4b_201111.las same file as 201111
t4 platform east
(.ps) (.pdf)
201124
t12backstays
road before vc looking
south

13Gb
.las

t12b_201124.las
to see where backstays
would fall

201201

platform collapses







201203
platform in dish
from helipad

370MB
.las
maxRange 570m
res:.8mm @10m
pltlow_201203.las


201209
T12 south face
from VC balcony

2.2GB
.las
maxRange 120m
res:.8mm@10m
t12_201209.las
check if tower is tilted

201223
T12 North face
from road next to VC

166MB
.las
maxRange
t12_201223_clipped.las
check if tower tilted. Removed road.

201228
T4 NorthFace
From SE edge of helipad

66MB
63MB
.las
.las
maxRange:270m
res:.8mm@10m
t4_201228.las
t4_201228_clipped.las
all data
try to remove ladder


Processing: /share/megs/phil/x101/p50/20mmdd/location/proccableall.pro, for processing each days data.

Measurement sets by location

    This shows the measurements done at each location:\


location
filename
notes
T12 mains
t12p_200831.las
didn't get to end of aux cables on platform

t12m_200902.las
got all of auxmain12W

t12m_200904.las
got most of auxmain12E
T12 backstays
t12backstay_1.6mm.las
from the sband power supply building. close to cables

t12b_200915_hpad.las from the helipad. long shot

t12b_200915_t4.las from the base of tower 4 (longer shot:)

t4p_201111.las
from west edge of helipad

t4b _201111.las
from east edge of helipad



T4 mains
t4p_200828.las
shot in 120 m max range. didn't make it all the way to the platform

t4m_200901.las
reshot from 200828 location in 270 m max range.

t4m_200902.las
from south rim wall. got all of t4auxmainS.

t4p_201111.las
from west edge of helipad

t4b_201111.las
from east edge of helipad
T4 backstays
t4b_200828_clipped.las
under the cables from the base of tower 4.

t4b_200915.las from the helipad

t4b_201111.las
from helipad east side.



T8 mains
t8m_200901.las
from sw-01 rim wall. got all of t8auxmainS.  

t8m_200915.las from nw--05 rim wall looking south. got a good shot of t8auxmainN

t8p1km_201021.las
from road in front of T8 base. 1km max range

t8p270m_201021.las
from road in front of T8 base. 270m max range.
T8 backstays
t8b_200903.las
from under the cables. really big file.

t8b_200915.las from the base of tower 4. long shot.




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