S1 LLO Calibration
Documents:
- Calibration of the LIGO detectors for
the First LIGO Scientific Run (LIGO Technical Document T030097-00-D),
Rana Adhikari, Peter Fritschel (LIGO-MIT), Gabriela Gonzalez, (Louisiana
State University), Mike Landry, Hugh Radkins (LIGO-LHO), Brian
O'Reilly (LIGO-LLO). May 2003. A comprehensive description of theory, procedures,
and errors.
- Notes on LIGO Detectors' Calibration,
GG, September 8 2002. A general note on notation, differences between conventions,
etc.
- Using Calibration Lines in S1/LLO
GG, October 12, 2002. An example on how we can use calibration lines.
- LLO Calibration for S1 data , Rana Adhikari,
GG, Brian O'Reilly, October 5 2002. A description of an LLO model, a measurement
of loop gain.
- LLO S1 Calibration, Rana Adhikari,
GG, Brian O'Reilly, October 23 2002. The complete story on calibration information
for S1 at LLO. Essentially an updated version of the previous document, propagating
the point calibration to all other times in S1.
- LLO Calibration for S1 segments
without calibration lines, GG, Novemeber 30. How we devised a calibration
for the times when the calibration lines were not turned on.
Data Files
- L1segments.txt Science segments in LLO.
- CalibrationData.txt Parameters alpha,
and alpha*beta to propagate 09/06 calibration in time.
- RepairedSegmentsWithLines.txt
Parameters alpha, and alpha*beta to propagate 09/06 calibration in time,
for segments that had a calibration line only part of the time.
- RepairedSegmentsWithoutLines.txt
Parameters alpha, and alpha*beta to propagate 09/06 calibration in time,
for segments that did not have a calibration line.
Reference Calibration done on Sept 6, 23:02 UTC:
- OpenLoopGain.txt 09/06 Open loop gain
(freq, amp, phase)
- ASQSensing.txt 09/06 Sensing function
C(f) for ASQ/(X/4km) in counts/strain (freq, amp, phase)
- ASQcalibration.txt 09/06 Calibration
function for AS_Q (in strain/counts).
Calibration for the times when inspirals were injected
These are "best guesses" translating alignment into missing calibration
information. Data: Frequency (Hz), Real part, Imaginary part (strain/counts)
These are all possible calibration functions at the times of injections.
For the given beta coefficient (obtained from DARM gain), use possible alpha*beta
coefficients: 0.4-1.4, in 0.1 steps to obtain all possible alpha coefficients.
From the reference open loop gain H(f) and sensing function C(f) of Sept6,
calculate the calibration function as (1+alpha*beta*H)/(alpha*C). The zipped
files contain 11 text files, each containing three columns: freq(Hz), real
and imaginary parts of Cal function in strain/counts. The names of the files
are of the form "ResponsePre(Post)RunABXX.txt" where XX=0.4-1.4 is the value
of alpha*beta used for that calibration function.
Measurements of Open Loop Gain function
Exported as ascii from XML files with DTT measurements.
Noise spectra
These are noise spectra at times enar the calibration swept sines. Exported
from DTT, contain frequency in Hertz, DARM_CTRL ands AS_Q in counts/rtHz.
Matlab programs
- S1darm.m: File with parameter and filter definitions
for the Simulin model. It has the actual filters used in S1, converted from
the coefficient file using Daniel Sigg's FOTON utility.
- S1darm_08.mdl, Open S1darm_08.mdl. Simulink models for
DARM loop used in S1, adpated from Rana's darm_08 model.
- CompareMeasGain.m: Compare modelled
and measured open loop gains on Sept 06.
- LoadModel.m: Load selected measurements of
open loop gains, compare with Simulink model.
- np.m: Rana's noise plotter, loads 09/06 input files,
plots residual noise (from AS_Q) and control displacement (from DARM_CTRL),
and compares with calibrated AS_Q using Simulink model.
- FinalCalib.m: produce the standard
calibration, sensing and open loop fucntions for Sept 06.
PAW programs
By Brian O'Reilly, to fit calibration lines.
Gabriela Gonzalez