Time domain implementation of DCPD cross correlation

Document #:

LIGO-T1700131-v1

Document type:

T - Technical notes

Abstract:

This document presents a time domain implementation of the cross correlated DCPD spectrum which suppresses sensing noises such as photon shot noise. The idea is to implement an additional signal stream in the front end digital system and produce a pair of artificial channels such that the cross correlated power spectrum of them then yields such sensing noise free spectrum. As opposed to the offline implementation based on a frequency domain consideration, this scheme offers two advantages: (1) calibration of the resulting spectrum is automatically achieved as it makes use of the existing calibration front end system and (2) it allows easy access to the cross correlated spectrum in the control room because it can be handled by DTT.

Files in Document:

• OnlineCrossCorr.pdf (171.3 kB)

Topics:

• Calibration
• Detector Characterization
• Data and Computing
• Commissioning

Authors:

• Kiwamu Izumi

Keywords:

aLIGO ISC OMC DCPD cross correlation sensing noise

Referenced by:

• LIGO-E1700107-v1: ECR: Time domain implementation of DCPD cross correlation