LIGO Document G1500823-v4
- These are calibrated strain and displacement spectra from the best lock stretch of ER7 Jun 9 2015, when the inspiral range was 65 Mpc.
The uncertainty in calibration is 50% and 20 [deg], valid between 10 and 5000 [Hz] (the uncertainty is larger and unquantified outside this band). For details see LHO aLOG 18769,
Further, these spectra are in the process of being reviewed and should be considered preliminary and are subject to change in future versions.
For details on how the time for this ASD was selected, see LHO aLOG 19275,
- Changes from v3 to v4:
Included mean removal and linear detrending of the time seried before pwelching, which had been left out after the switch from asd2.m which does it automatically.
Changes from v2 to v3:
No change to content, merely renaming files to reflect the date that the data was taken as opposed to the date on which the data was analyzed.
Changes from v1 to v2 :
Changes in analysis of data result of review.
- Changed inspiral range calculation to use
- Changed the asd calculation from averaging frequency bins of an FFT of the entire time series (i.e. using asd2.m) to using Welch's method, where the time series is divided up into chunks, and then the FFT of each chunk is used to compute the average.
- New ASD / FFT parameters such that the bin width is 0.125 [Hz], with 100 averages (i.e. a ~400 [sec] time series).
- Tweaked the method for determining the best part of the lock stretch to combine points via the sum of squares of the residual at each point instead of the median of all residual points.
DCC Version 3.4.2, contact