Calculating the precision of tilt-to-length coupling estimation and noise subtraction in LISA using Fisher information

Abstract

Tilt-to-length (TTL) noise from angular jitter in LISA is projected to be the dominant noise source in the milli-Hertz band unless corrected in post-processing. The correction is only possible after removing the overwhelming laser phase noise using time-delay interferometry (TDI). We present here a frequency domain model that describes the effect of angular motion of all three spacecraft on the interferometric signals after propagating through TDI. We then apply a Fisher information matrix analysis to this model to calculate the minimum uncertainty with which TTL coupling coefficients may be estimated. Furthermore, we show the impact of these uncertainties on the residual TTL noise in the gravitational wave readout channel, and compare it to the impact of the angular witness sensors' readout noise. We show that the residual TTL noise post-subtraction in the TDI variables for a case using the LISA angular jitter requirement and integration time of one day is limited to the 8\,pm/$\sqrt{\mathrm{Hz}}$ level by angular sensing noise. However, using a more realistic model for the angular jitter we find that the TTL coupling uncertainties are 70 times larger, and the noise subtraction is limited by these uncertainties to the 14\,pm/$\sqrt{\mathrm{Hz}}$ level.

References in corpus (6)

• Use and Abuse of the Fisher Information Matrix in the Assessment of Gravitational-Wave Parameter-Estimation Prospects
• LISA Pathfinder Platform Stability and Drag-free Performance
• Report on the second Mock LISA Data Challenge
• Time Delay Interferometry combinations as instrument noise monitors for LISA
• Data series subtraction with unknown and unmodeled background noise
• Geometric tilt-to-length coupling in precision interferometry: mechanisms and analytical descriptions

Cited by in corpus (5)

• Tilt-to-length coupling in LISA Pathfinder: a data analysis
• Heavy-tailed likelihoods for robustness against data outliers: Applications to the analysis of gravitational wave data
• On point-ahead angle control strategies for TianQin
• Post-processing subtraction of tilt-to-length noise in LISA in the presence of gravitational wave signals
• Tilt-To-Length Coupling in LISA -- Uncertainty and Biases