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LIGO-G020051-00-Z

Isabel Leonor (w/ Robert Schofield) University of Oregon

LIGO Reduced Data Sets
E7 standard reduced data set RDS generation for future runs decimation examples


Standard RDS ­ Guidance from LSC White Paper

Data set levels outlined in LSC white paper: Level 0: Full IFO data stream (not archived) Level 1: Archived reduced data set
· all important IFO and PEM channels · used principally for detector diagnostics

Level 2: IFO strain and data quality channels
· basic IFO strain data, most important IFO and PEM channels · used for detailed science analysis

Level 3: Whitened GW strain data
· best estimate of GW strain
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LSC Meeting, Livingston March 20-23, 2002


E7 Run ­ 400 Hours in Winter
(and lots and lots of data)

3 Tbytes (w/o decimation) 11 Tbytes LLO: 401 hours LLO: 4.0 Tbytes 1.0 Tbyte 786 channels 75 channels LHO: 410 hours LHO: 7.2 Tbytes 2.0 Tbytes 4601 channels 106 channels
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LSC Meeting, Livingston March 20-23, 2002


What's in the Reduced Frames for E7? (located on LDAS disks)
all LSC error channels, plus DARM_CTRL some ASC channels
· wavefront sensors for LHO · optical levers for LLO · transmitted light in arms

a few IOO and PSL channels
· frequency monitors

many PEM channels
· seismometers, accelerometers, microphones, magnetometers, voltage monitors

several slow channels
· weather, pre-stabilized laser, optical levers

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LSC Meeting, Livingston

March 20-23, 2002


Important
need users from astrophysics groups to try E7 reduced frames need feedback about content of E7 RDS to help prepare future RDSs what important channels were not included? which channels were most used? Just follow the links from the E7 web page!
(channel list, RDS directories, file names and sizes, time gaps)
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LSC Meeting, Livingston March 20-23, 2002


Reduced Data Sets for Future Runs
RDS will be generated using LDAS use frameAPI and datacondAPI to strip channels and to perform decimation
user testing of functionalities for RDS generation is currently ongoing

RDS generation will be tested in a mock data challenge

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LSC Meeting, Livingston

March 20-23, 2002


Important
what channels should be included in future Level 2 reduced data sets? should decimation be done on some channels?
need to study effects of data decimation e.g. effects on output of astrophysics search codes, DMT trigger rates

7

LSC Meeting, Livingston

March 20-23, 2002


Decimation Example
(using injected signal of P. Shawhan, et. al.)
adc counts

60 40 20 0 -20 -40
8.48

(a) original data GPS 694493712 L1:LSC-AS_Q

DFT magnitude

10 7

10 6

blip injected signal

GPS 694493720.25 0.5 sec duration L1:LSC-AS_Q original data decimated data

10 5

10 4

10
8.49 8.5 8.51 8.52 8.53

3

blip injected signal

relative time (seconds)
adc counts

60 40 20

(b) decimated data

10 2

10

1
0 -20 -40
8.48 8.49 8.5 8.51 8.52 8.53

10

-1

10

-2

10

-1

1

10

10

2

10

3

relative time (seconds)

frequency (Hz)

8

LSC Meeting, Livingston

March 20-23, 2002


Decimation Examples ­ Time Series
adc counts
adc counts

300 200 100 0 -100 -200
0.475 0.48 0.485 0.49 0.495

800 600 400 200 0 -200 -400

(a) H2:LSC-AS_Q GPS 693591712 original data decimated data
0.5 0.505

-600 -800 -1000

(c) H2:LSC-AS_Q GPS 693591744 original data decimated data
0.3 0.35 0.4 0.45

adc counts

adc counts

0

relative time (seconds)
3500 3000 2500 2000

0.51

0.515

relative time (seconds)

0.5

0.55

-50

-100

-150
1500

-200

(b) H2:LSC-AS_Q GPS 693591728 original data decimated data
0.47 0.475 0.48 0.485 0.49 0.495 0.5

1000 500
0.44

(d) H2:IOO-MC_F GPS 693591728 original data decimated data
0.442 0.444 0.446 0.448

-250

relative time (seconds)

0.505

0.51

relative time (seconds)

0.45

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LSC Meeting, Livingston

March 20-23, 2002


Decimation Examples ­ Fourier Transform
10 5

(a) H2:LSC-AS_Q GPS 693591744 average over 16 seconds

DFT magnitude ratio (original/decimated)

DFT magnitude

10 6

12 10 8 6 4 2 0
10
12 10 8 6 4 2 0
10

(a) H2:LSC-AS_Q GPS 693591744

10 4

10 3

original data decimated data

10 2

10
DFT magnitude

-1

1

10

10

2

10

3

-1

1

10

10

2

10

3

frequency (Hz)
10 7

frequency (Hz)
(b) H2:IOO-MC_F GPS 693591728

(b) H2:IOO-MC_F GPS 693591728 average over 16 seconds

10 6

10 5

10 4

10 3

original data decimated data

10 2
-1
2
3

DFT magnitude ratio (original/decimated)

10

1

10

10

10

-1

1

10

10

2

10

3

frequency (Hz)

frequency (Hz)

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LSC Meeting, Livingston

March 20-23, 2002


Summary
E7 reduced data set now available ­ try it! need feedback from users of E7 RDS to help prepare for future RDSs LDAS to be used to generate future RDSs need to decide if decimation should be done on some channels for future RDSs
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LSC Meeting, Livingston March 20-23, 2002