Analysis of the residual force noise for the LISA Technology Package

TL;DR

This paper investigates the noise sources affecting test mass motion in the LISA Pathfinder mission, emphasizing the impact of statistical and parameter uncertainties on force noise estimation.

Contribution

It provides a detailed analysis of how statistical and systematic uncertainties influence force noise measurements in the LISA Technology Package.

Findings

Statistical properties dominate the uncertainty in force noise spectral density.

Parameter uncertainties have a smaller impact compared to statistical fluctuations.

Simulated data analysis highlights the importance of spectrum estimator properties.

Abstract

The analysis of the noise sources perturbing a test mass (TM) geodesic motion is the main scientific objective of the LISA Technology Package experiment (LTP) on board of the LISA Pathfinder space mission. Information on force noise acting on TMs are obtained with a data reduction procedure involving system parameters. Such parameters can be estimated from dedicated experimental runs. Therefore the final estimation of force noise is affected by two sources of uncertainty. One is statistical and connected to the random nature of noisy signals. The other is connected to the uncertainties on the system parameters. The analysis of simulated LTP data is indicating that the major contribution to the force noise power spectral density uncertainties is coming from the statistical properties of the spectrum estimator.