Alfa compression by radars using pdev

23mar08
Links:
Data processing
Table of the data sets
06mar08: sitting az=340, za=18
11mar08 sitting at az 340, za=18
12mar08 sitting at az 340, za=17
13mar08 zastrips az=180, za=2->19.5->2. Radars: remy ,aerostat, no faa.
18mar08 sitting at az=340,za=18. rotate alfa.
18mar08 za strips at az=360 and 180. za 19.5->2->19.5. faa,remy, no Aerostat
Table of za locations for jumps when at the meridian.
Conclusions


INTRO:  (top)

        Jumps in Alfa's power levels with long recovery times (greater than seconds) has been seen for some time (see alfa pwr jumps). During the painting project alfa was brought down to the lab to be worked on.  After reinstalling alfa in the dome, test were done with the pdev spectrometer to measure the power jumps. The setup was:

Processing the data:


The datasets:  (top)

    Terminology:


Data Sets with links to daily descrption and plots
date
fileNumber
Link to plots
nchan
time
secs
Jumps
beams
radars
present
az/za
alfa
angle
Notes
06mar08
000
512
24
-
faa,ps
285/10

pshift 0x155,dshift=0, accum overflow
100
3,4
faa,ps,remy
340/18

overflow
200
0,2,3,4
faa,ps,remy

overflow
300
2,3,4
faa,ps,remy

dshift=5 no overflow
400
0,2,3,4,5
faa,ps,remy

dshift=5
11mar08
000
512
24
3
faa,ps,remy
340/18
19
pshift:0x1ff small jumps.
100
3
faa,ps,remy
19

200
3
faa,ps,remy
0

12mar08
000
512
24
-
faa,ps,remy,aero
340/17

This was not at 340,18, not jumps seen

100
-
faa,ps,remy

13mar08
zastrip.0..2
128
875
-
aero,remy
180/(2..19.5)
19
dshift=0 some accum overflows. 02deg/sec
zastrip.100..102
-
180/(19.5..2)
dshift=1, no overflows. -.02 deg/sec
18mar08
rotate alfa

sit.000
128
24
3,4
faa,ps,remy
340/18
19
see how saturation, radar strength changes with alfa rotation angle. filenames: sit340_18.20080318...

sit.100
0,1,2,3,4
faa,ps,remy
0
sit.200
1,3,4,5
faa,ps,remy
40
sit.300
0,1,3,4,5
faa,ps,remy
60
18mar08
zaStrips
zaN.000..002
128
875

faa,ps,remy
360/(19.5..2)
19
za strips move at .02 degs/sec. Filenames: zaswingN, zaswingS
zaN.100.102

faa,ps,remy
360/(2..19.5)
zaS.000.002

faa,ps,remy
180/(19.5..2)
zaS.100.102

faa,ps,remy
180/(2..19.5)











06mar08 sitting az=340, za=18   (top)

    5 scans were taken on 06mar08. There was overflow in the pdev device for the first 3 until dshift was set to 5.

Comments:

processing: 080306/rdrsat.pro

11mar08 sitting at az 340, za=18.   (top)

    Fixed the saturation levels in pdev. Took two  scans at alfa angle = 19 degrees and then 1 scan at alfa angle=0.
processing: 080311/rdrsat.pro

12mar08 sitting at az 340, za=17  (top)

    Sat at 340,17 rather than 340,18 and saw no jumps. Didn't record the alfa angle.
processing: 080312/rdrsat.pro

13mar08 zastrips az=180, za=2->19.5->2. Radars: remy ,aerostat, no faa.  (top)

   Two za strips were done at az=180. 2->19.5 degrees followed by 19.5->2 degrees. The dome moved at .02 degrees/second. The 1450 band data was smoothed and then decimated to .2 seconds. The radar bands had peak holds done over the same time step. The radars rotate at 12 seconds. In this time the za moved by .02*12 = .24 degrees. The repeatability will be limited by this value ( the za position of compression going up will be a little different than the za position of the compression going down.
    During the data taking the Remy and aerostat radars were running. The faa radar was off. No compression was seen in the
entire dataset.
The plots are:

Daily summary:


processing: x101/080313/rdrsatza.pro

18mar08 sitting at az=340,za=18. rotate alfa.  (top)

    Data was taken at 4 settings of the alfa rotation angle: 19,0,40 and 60 degrees to see how the jumps moved from beam to beam. When rotating from 0 to 60 degrees, beams N -> N-1 so you might expect to see the jumps move from beam to beam. A 60 degree rotation moves 1 beam to the next, but the waveguide probes are not at the same angle as the previous beam.
    The the rotation from 0 to 60 degrees mapped the strongest compressions 2,4 -> 3, 5 which was expected.
processing: x101/080318/rdrsatrot.pro

18mar08 za strips at az=360 and 180. za 19.5->2->19.5. faa,remy, no Aerostat  (top)

    Four: za strips were done:
    The dome moved at .02 degrees/second. The 1450 band data was smoothed and then decimated to .2 seconds. The radar bands had peak holds done over the same time step. The radars rotate at 12 seconds. In this time the za moved by .02*12 = .24 degrees. The repeatability will be limited by this value ( the za position of compression going up will be a little different than the za position of the compression going down.
    Jumps in the total power (with long recovery times > secs) were seen. The data is plotted vs za. When moving down in za, the jumps are from the right to left in the plots.When moving up the jumps go from  small to larger za.
    During the data taking the Remy , punta Salinas, and FAA radar were running. The Aerostat radar was off. Peaks in the aerostat plots are from the punta  Salinas radar (which shares the same frequencies).
The plots are:
Compression was seen in the up down directions when the azimuth was at 360. It was not seen when the za swings were at an azimuth of 180. All of the jumps lined up with just the FAA radar.


Za locations for saturation during za strips
za
Deg
az
Deg
direction
Beams with
Saturation
maximum
 strength
3.0
360
up
5
<1%
5.45
360
down
3,4
1%
5.55
360
up
3,4,5
1%
6.15
360
down
4
<1%
6.29
360
up
3,4
2%
6.4
360
down
3,4,5
2%
13.87
360
down
3,4
1%
13.97
360
up
3.45
2%
17.23
360
down
3,4
4%
17.35
360
up
2,3,4,5
1%

Daily Summary:

processing: x101/080318/rdrsatza.pro

Conclusions:  (top)


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