Message ID: 2439
Entry time: Tue Oct 1 13:46:49 2019
In reply to: 2438

Author:

anchal

Type:

DailyProgress

Category:

NoiseBudget

Subject:

Using bayesian inference to estimate loss Angles

I used the method described in Section V of https://arxiv.org/abs/1406.4467, to do a bayesian inference using mechanical ring-down measurements of coating loss angles by Steve Penn (recently reported in https://dcc.ligo.org/LIGO-G1901676) as a prior. I assumed all probability distributions to be gaussian. We are clearly not close to measuring the Brownian noise as with present uncertainty limits reported by Penn et al, the prior distribution and the likelihood distribution do not overlap with each other at all, giving us no meaningful result. Note the different limits in x-axis on first and second plot.

This was a quick run of this though, just to set up the method. Ideally, I should use integrated noise in some frequency range around 300 Hz to use as the measurement. Also, Steve Penn actually did not report any uncertainty value with his measurements, so I assumed the uncertainty the same as his previous measurement. Looking forward to the more formal release of his data.