Non-linear parameter estimation for the LTP experiment: analysis of an operational exercise

TL;DR

This paper discusses a non-linear parameter estimation approach for the LISA-Pathfinder mission's experiments, aiming to identify and optimize system parameters to reduce disturbances on test masses for gravitational wave detection.

Contribution

It introduces a non-linear analysis method using the LTPDA Toolbox to improve parameter estimation and reduce degeneracies in the LTP experiment setup.

Findings

Progress in non-linear analysis techniques for LTP

Identification of critical parameters for disturbance reduction

Enhanced parameter estimation accuracy

Abstract

The precursor ESA mission LISA-Pathfinder, to be flown in 2013, aims at demonstrating the feasibility of the free-fall, necessary for LISA, the upcoming space-born gravitational wave observatory. LISA Technology Package (LTP) is planned to carry out a number of experiments, whose main targets are to identify and measure the disturbances on each test-mass, in order to reach an unprecedented low-level residual force noise. To fulfill this plan, it is then necessary to correctly design, set-up and optimize the experiments to be performed on-flight and do a full system parameter estimation. Here we describe the progress on the non-linear analysis using the methods developed in the framework of the \textit{LTPDA Toolbox}, an object-oriented MATLAB Data Analysis environment: the effort is to identify the critical parameters and remove the degeneracy by properly combining the results of different experiments coming from a closed-loop system like LTP.