Pointing/System checks during platform painting
30mar07
Sections:
Dates
26mar07 measurements
30mar07 measurements
31mar07 measurements
01apr07 measurements
02apr07 measurements
04apr07 measurements
05/06apr07 measurements
07apr07 measurements
09apr07 lbw measurements
10apr07 measurements
11apr07 measurements
12apr07 measurements
13apr07 measurements
17apr07 measurements
18apr07 measurements
19apr07 measurements
20apr07 measurements
21apr07 measurements
23apr07 measurements
24apr07 measurements
Tilt sensor measurements
Plots
26,27Mar07
before the painting (.ps) (.pdf)
30mar07
pointing checks (.ps) (.pdf)
31mar07
pointing checks (.ps) (.pdf)
01apr07
pointing checks (.ps) (.pdf)
02apr07
pointing checks (.ps) (.pdf)
04apr07
pointing checks (.ps) (.pdf)
05/06apr07
pointing checks (.ps) (.pdf):
07apr07
pointing checks (.ps) (.pdf)
09apr07
pointing checks (.ps) (.pdf)
10apr07
pointing checks (.ps) (.pdf)
11apr07
pointing checks (.ps) (.pdf)
12apr07
pointing checks (.ps) (.pdf)
13apr07
pointing checks (.ps) (.pdf)
17apr07
pointing checks (.ps) (.pdf)
18apr07
pointing checks (.ps) (.pdf)
19apr07
pointing checks (.ps) (.pdf)
20apr07
pointing checks (.ps) (.pdf)
21apr07
pointing checks (.ps) (.pdf)
23apr07
pointing checks (.ps) (.pdf)
24apr07
pointing checks (.ps) (.pdf)
The pointing was monitored during the preparation
for
the platform painting. The distribution of the weight on the platform
was
being changed. Each day the daily pointing errors, the cumulative
pointing
errors to that data, and the gain/tsys/sefd/beamwidth are plotted.
- 29mar07: installed cables t8 corner. Raised about 900 lbs
- 30mar07: rain.. not much work.
- 31mar07:
- installed cables t12,T4 corners.
- removed laser shack (about 2700 lbs from corner 4).
- 01apr07: about 500 lbs lifted to platform. standoffs for t12
corner
- 02apr07: half the lead from corner 4 removed?
- 03apr07: rest of lead removed from corner 4.
- 6900 lbs of lead was removed from corner 4 + 500 misc lbs.
- Total removed from corner 4 is: 2700(laser shack) + 6900 lbs
(lead) +
500
lbs (misc) = 10100 lbs.
- 04apr07:
- about half the lead from corner 12 removed.
- Tilt sensor az spins done then tiedowns were readjusted to
compensate
for
tilt (around 17:30).
- The tiedown reference was changed from:
- [14.8751 14.6161 13.2431] to
- [14.6808 15.4018 12.6517 ] prior to taking the pointing data.
- X102 data data taken starting around 17:30
- dome disable cable broken around 19:00.
- both azimuth encoders reset (after x102 data taken)
- 05apr07: working on az encoders. took x102 data in the
evening.
- 06apr07:Good Friday. No work on platform.
- Took x102 data
- After x102 data, computed az*sin(za) pointing error and updated
pointing
model to correct for az encoder offsets (caused by repositioning after
the reset)
- 07apr07:
- Rest of lead corner 12 removed 9000+ lbs in total removed.
- Az swings done with tilt sensors. Fit for 1az term and then
updated
tiedown
default positions to remove the tilt.\
- The new tiedown reference is: [14.9277,15.4312 12.3754]
- 31mar-07apr: Weight summary:
- 3300 lbs steel outriggers cables raised + 600 lbs wooden
blocks.
- 18932 lbs removed: laser shack,sband power supply calbe
splice tank and dielectric oil, lead.
- 08apr07:
- 09apr07:
- raised 9 brackets 150 lbs each. Placed in corners 8 and 12.
- checked lbw pointing after installation
- 17apr07: alfa lower from dome to electronics lab for maintenance.
- 18apr07: netting on bottom chord of each corner of triangle
installed.
- 19apr07: Vertical netting installed corner 12.
- 20apr07: Vertical netting installed corner 8.
- 21apr07: Vertical netting installed 1 side corner 4. distomat 3
not working.
- 22apr07: Distomat 3 now working. The vertical tarp had been
covering it.
- 23apr07: Floor on T12 corner.. (full of water). 2 sides corner 4
- 24apr07: Floor on corners full of water
- 25apr07:Stopped observing. Painting shutdown has started. All 3
corners have the 3 sides of the tarps up. No roof yet.
The Measurements: top
26,27Mar07
before the painting (.ps) (.pdf):
Tracked 3 sources using sbn. Pointing was ok.
- Page 1: pointing errors
- Page 1: gain,Tsys,Sefd,Beamwidths.
processing:
x101/070326/mmdoit.pro
30mar07
pointing checks (.ps) (.pdf):
top
Data taken with sbn from 18 to 20 hrs AST.
The plots show the 30mar07 data plotted with a srcname suffix
of
_m30.
The 26mar07 data is also plotted with a srcname suffix of
_m26.
Page 1: pointing errors fro 30mar07.
Page 2: pointing errors for 26,27,30 mar07 overplotted.
I don't see any obvious changes in the pointing. The drift to positive
errors around az=80 was there previously (but it had been centered
closer
to azerr=0).
Page 2: gain,Tsys,Sefd,Beamwidths.
processing: x101/070330/chkpnt.pro
31mar07
pointing checks (.ps) (.pdf):
top
Data taken with sbn from 17 to 18 hrs AST. The laser shack
had been
removed earlier in the day.
The plots show the 31mar07 data plotted with a srcname suffix
of
_m31.
The 30 and 26mar07 data is plotted with suffixes of _m30 and _m26.
Page 1: the pointing errors for 31mar07 by themselves.
Page 2: Cumulative pointing errors since 26mar07. The
source
B0534+342
was tracked on 31mar07 and on 26mar07. The za errors have moved up a
few
arc seconds from the 26mar07 data. The az errors are consistent with
the
big dip around 160 degrees.
Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070331/chkpnt.pro
01apr07
pointing checks (.ps) (.pdf):
top
Data taken with sbn from 16 to 18 hrs AST. About 500 lbs of
metal
had been lifted today.
The plots show the 01apr07 data plotted with a srcname suffix
of
_a01.
The 21,30 and 26mar07 data is plotted with suffixes of _m31,_m30,
and
_m26.
Page 1: the pointing errors for 01apr07 by themselves.
Page 2: Cumulative pointing errors since 26mar07. The
source
B0618+145
was tracked on 01apr,26mar, and 30mar. There is a definite shift of the
za errors around az=-80. This is probably the 1az term from the
platform
tilt.
Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070401/chkpnt.pro
02apr07
pointing checks (.ps) (.pdf):
top
Data taken with sbn from 16 to 19 hrs AST. Half the lead
from corner
4 was removed earlier today (800 lbs?)
The plots show the 02apr07 data plotted with a srcname suffix
of
_a02.
Page 1: the pointing errors for 02apr07 by themselves. You can
clearly
see the 1 azimuth term in the za errors. It is peaking at az=120 deg
(corner
4). The az errors peak 90 degrees away (around 210 deg) The amplitude
is
aound 20 arcseconds.
Page 2: Cumulative pointing errors since 26mar07. The data
is
starting
to get mixed up since each day something caused a change in the
pointing.
Page 3: gain,Tsys,Sefd,Beamwidths. Looks like the flux for
0453+227
is a little low at 2380Mhz.
processing: x101/070402/chkpnt.pro
04apr07
pointing checks (.ps) (.pdf):
top
Data taken with sbn from 17:30 to 19 hrs AST. All the lead
from corner
4 and half the lead from corner 12 was removed. Az spins were done with
the tilt sensors from 16:30 to 17:30. The 1 azimuth term was fit to the
data and the tiedown reference positions were moved from
[14.165,13.905,12.522]
to [13.9707,14.6907,11.9306] [td12,4,8]. The major difference was the
extra
pulldown on td4 (13.905 to 14.691) to compensate for the 10000 lbs
removed
from corner 4.
The plots show the 04apr07 data plotted with a srcname suffix
of
_a04.
Page 1: the pointing errors for 04apr07 by themselves. The 1 az
term is
no longer as prominent as 02apr07.
Page 2: Cumulative pointing errors since 26mar07.
Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070404/chkpnt.pro
05/06apr07
pointing checks (.ps) (.pdf):
top
- Data was taken on 05apr07 16:30 to 21:30 and on
06apr07 from
16:30 to 18:00 using sbn. This data was taken after the azimuth
encoders were repositioned and reset on 05apr07 .
- Page 1. The pointing errors for 05,06apr07. The
3rd
plot
"az errors vs za" shows the az encoder offset. The plots are in great
circle
arc seconds. An az encoder offset would show up az an azEncErr*sin(za).
Two of the sources show the ramp in za. B0518+165 doesn't. This may be
because it does not cover a very large azimuth range and the za slope
is
being offset by a 1az or 3 az term.
- Page 2:
- The top plot shows azErr versus za (on the
sky).
- The bottom plot is azErr*sin(za). This is the
az
encoder
offset. The average value for the 3 sources is -35.9 arc seconds (at
the
encoder).
- A -35.9 Asecs encoder error at the 60 foot
radius
is a positioning
error of -.123 inches. You need to subtract this value to get the
correct
encoder value. The pointer should have been positioned +.123 inches
(clockwise)
from where it was (on the scribe mark). We centered the index on
the scribe mark. As I recall, the previous positioning of the
encoder
index was to the right of the mark (back in november). That was when
the
pointing model azerr*sin(za) was computed. We also had the dome at 8
degrees
za when we did this. It may have been at za=10 the last time the index
was set.
- The pointing models were updated. The
az*sin(za)
term was
incremented by +35.9 asecs.
- Page 3: pointing errors for data taken in apr04
- Page 4: gain,tsys,sefd, beamwidth for data
taking
in apr04.
processing: x101/070406/chkpnt.pro
07apr07
pointing checks (.ps) (.pdf):
top
- The rest of the lead from corner 12 was removed earlier in the
day. The
total removed was about 9600 lbs.
- 16:45 to 17:15 azimuth swings done with tilt sensors to measure
the
platform
tilt. The tiedown positions were then updated to remove the tilt. he
tiedown
reference position are now:
- [td12 ,
td4
,td8]
- [14.6807,15.4107,12.6516] tdRef set 04apr07 after td4 weight
removed.
- [14.9276,15.4311,12.3753] tdRef set 07apr07 after td12 weight
removed.
- There is now a 3 inch difference in the stroke of td8 and td4
- Data taken with sbn from 17:30 to 21:30 hrs AST.
- The plots show the 07apr07 data plotted with a srcname suffix
of
_a07.
- Page 1: the pointing errors for 07apr07 by themselves. The az
errors
versus
za are now drifting up to about +10 asecs. It may be that the -35.9
encoder
offset put in 06apr07 was not necessary.
- Page 2: Cumulative pointing errors since 01apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070407/chkpnt.pro
09apr07
pointing checks (.ps) (.pdf):
top
- Data taken with lbw from 16:30 to 20:00 hrs AST. This was
to
check the pointing with lbw after it had been reinstalled in the dome o
the pprevious week.
- The plots show the 09apr07 lbw data plotted with a srcname suffix
of
_a09.
- Page 1: the pointing errors lbw from 09apr07 . The errors look
similar
to the sbn errors of the previous days.
- Page 2: gain,Tsys,Sefd,Beamwidths for the lbw data.
processing: x101/070409/chkpnt.pro
10apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:00 to 19:00 hrs AST.
- The plots show the 10apr07 data plotted with a srcname suffix
of
_a10.
- Page 1: the pointing errors for 10apr07 by themselves. It rained
while
this data was
taken but the distomats/tiedowns continued to run. The one or two
outliers may be because of the
rain.
- Page 2: Cumulative pointing errors since 02apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070410/chkpnt.pro
11apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:30 to 21:30 hrs AST.
- The plots show the 11apr07 data plotted with a srcname suffix
of
_a11.
- Page 1: the pointing errors for 11apr07 by themselves.
- Page 2: Cumulative pointing errors since 05apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths. The red -- and black
triangles
are the 09apr07 lbw data.
processing: x101/070411/chkpnt.pro
12apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 18:00 to 18:46 hrs AST. The time
was
shortened because of an oil leak
in azimuth motor 82 transmission that had to be repaired prior to
observing.
- The plots show the 12apr07 data plotted with a srcname suffix
of
_a12.
- Page 1: the pointing errors for 12apr07 by themselves.
- Page 2: Cumulative pointing errors since 06apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths. The offset Tsys,sefd
data is
from the 09apr07 lbw data.
processing: x101/070412/chkpnt.pro
13apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:00 to 19:00 hrs AST.
- The plots show the 13apr07 data plotted with a srcname suffix
of
_a13.
- Page 1: the pointing errors for 13apr07 by themselves.
- Page 2: Cumulative pointing errors since 07apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths. The offset Tsys,sefd
data is
from the 09apr07 lbw data.
processing: x101/070413/chkpnt.pro
17apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:00 to 20:45 hrs AST. Alfa was
removed earlier in the day. There was rain during the observations but
the distomats continued running.
- The plots show the 17apr07 data plotted with a srcname suffix
of
_a17.
- Page 1: the pointing errors for 17apr07 by themselves. Removing
alfa did not make a large change in the pointing.
- Page 2: Cumulative pointing errors since 09apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths. The offset Tsys,sefd
data is
from the 09apr07 lbw data.
processing: x101/070417/chkpnt.pro
18apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:00 to 20:45 hrs AST. There was
overcast/drizzle during the observations but the distomats continued
running.
- The plots show the 18apr07 data plotted with a srcname suffix
of
_a18.
- Page 1: the pointing errors for 18apr07 by themselves.
- Page 2: Cumulative pointing errors since 10apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070418/chkpnt.pro
19apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:00 to 19:00 hrs AST.
- The plots show the 19apr07 data plotted with a srcname suffix
of
_a19.
- Page 1: the pointing errors for 19apr07 by themselves.
- Page 2: Cumulative pointing errors since 11apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070419/chkpnt.pro
20apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 18:24 to 19:00 hrs AST. There had
be a power outage earlier in the day. Most of the observing time was
lost.
- The plots show the 20apr07 data plotted with a srcname suffix
of
_a20.
- Page 1: the pointing errors for 20apr07 by themselves.
- Page 2: Cumulative pointing errors since 12apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070420/chkpnt.pro
21apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:00 to 18:00 hrs AST. Distomat 3
was not working. Looks like that covered or bumped the retroreflector
when they covered that side today.
- The plots show the 21apr07 data plotted with a srcname suffix
of
_a21.
- Page 1: the pointing errors for 21apr07 by themselves.
- Page 2: Cumulative pointing errors since 13apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070421/chkpnt.pro
23apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 16:00 to 19:00 hrs AST. Heavy
rain,
distomats not working. Flooring in corners of platform full of water.
- The plots show the 23apr07 data plotted with a srcname suffix
of
_a23.
- Page 1: the pointing errors for 23apr07 by themselves. Both the
az and za errors have larger than normal negative offsets. This is
either from the tiedowns not working (rain) or the water in the floor
of corner 12 and 8 tilting the platform.
- Page 2: Cumulative pointing errors since 17apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070423/chkpnt.pro
24apr07
pointing checks (.ps) (.pdf):
top
- Data taken with sbn from 13:45 to 19:00 hrs AST.
Rain with distomats not working.
- The plots show the 24apr07 data plotted with a srcname suffix
of
_a24. This is the last day of observing.
- Page 1: the pointing errors for 24apr07 by themselves.
- Page 2: Cumulative pointing errors since 17apr07.
- Page 3: gain,Tsys,Sefd,Beamwidths.
processing: x101/070424/chkpnt.pro
Tilt sensor measurements top
Tile sensor measurements were done to look for a
change
in the 1az term in the platform tilt.
- 27mar07
az swings:
- 31mar07
az swings:
- The 1az term has increased from about .006 to .010 after the
laser
shack
was removed.
- 04apr07
az swings:
- The lead had been removed from corner 4 and some from 12. Az
swings were done, the tiedowns were moved, and then another set of az
swings were done.
- The original tiedown reference position was: [14.8751 14.6161
13.2431]
- The new tiedown reference position is : [14.6808 15.4018
12.6517 ]
- Tiedown 4 is pulling more because of the lead removed from
corner 4.
- 07apr07
az swings, updated tiedown positions.
- The tiedowns were returned to the 27mar07 reference position
and then two az swings were done with the tilt sensors. The 1 az term
was fit and then the tiedowns were moved to give the same platform tilt
as 27mar07.
- The new tiedown reference position is: [14.9277,15.4312 12.3754]
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home ~phil