Showing papers by "Michele Armano published in 2015"
European Space Agency1, Max Planck Society2, Paris Diderot University3, Imperial College London4, University of Trento5, Airbus Defence and Space6, University of Birmingham7, Jet Propulsion Laboratory8, ETH Zurich9, Institut de Ciències de l'Espai10, European Space Operations Centre11, University of Zurich12, University of Glasgow13, Goddard Space Flight Center14, Polytechnic University of Catalonia15
TL;DR: The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors as discussed by the authors, and the Pathfinder spacecraft will perform drag free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass.
Abstract: The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this 'suspension noise'. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.
8 citations
Institut de Ciències de l'Espai1, Max Planck Society2, European Space Agency3, Paris Diderot University4, Imperial College London5, University of Trento6, Airbus Defence and Space7, University of Birmingham8, ETH Zurich9, European Space Operations Centre10, University of Zurich11, University of Glasgow12, Goddard Space Flight Center13, Polytechnic University of Catalonia14
TL;DR: In this paper, the authors report on how these kind of thermal diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft.
Abstract: Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations.
7 citations
European Space Agency1, Max Planck Society2, Paris Diderot University3, Imperial College London4, University of Trento5, Airbus Defence and Space6, University of Birmingham7, ETH Zurich8, Institut de Ciències de l'Espai9, European Space Operations Centre10, University of Zurich11, University of Glasgow12, Polytechnic University of Catalonia13, Goddard Space Flight Center14
TL;DR: In this paper, the authors show the first results on the magnetic experiments during an end-to-end LISA Pathfinder simulation, and describe the methods under development to map the magnetic field on-board.
Abstract: Magnetically-induced forces on the inertial masses on-board LISA Pathfinder are expected to be one of the dominant contributions to the mission noise budget, accounting for up to 40%. The origin of this disturbance is the coupling of the residual magnetization and susceptibility of the test masses with the environmental magnetic field. In order to fully understand this important part of the noise model, a set of coils and magnetometers are integrated as a part of the diagnostics subsystem. During operations a sequence of magnetic excitations will be applied to precisely determine the coupling of the magnetic environment to the test mass displacement using the on-board magnetometers. Since no direct measurement of the magnetic field in the test mass position will be available, an extrapolation of the magnetic measurements to the test mass position will be carried out as a part of the data analysis activities. In this paper we show the first results on the magnetic experiments during an end- to-end LISA Pathfinder simulation, and we describe the methods under development to map the magnetic field on-board.
7 citations
European Space Agency1, Max Planck Society2, Paris Diderot University3, Imperial College London4, University of Trento5, Airbus Defence and Space6, University of Birmingham7, ETH Zurich8, Institut de Ciències de l'Espai9, European Space Operations Centre10, University of Zurich11, University of Glasgow12, Polytechnic University of Catalonia13, Goddard Space Flight Center14
TL;DR: In this paper, the effective direction and amplitude gain of each of the 6 thrusters of the cold gas micro-propulsion system used during the LISA-Pathfinder mission is characterized.
Abstract: The cold gas micro-propulsion system that will be used during the LISA-Pathfinder mission will be one of the most important component used to ensure the "free-fall" of the enclosed test masses. In this paper we present a possible strategy to characterize the effective direction and amplitude gain of each of the 6 thrusters of this system.
5 citations
European Space Agency1, Max Planck Society2, Paris Diderot University3, University of Trento4, Airbus Defence and Space5, University of Birmingham6, ETH Zurich7, Spanish National Research Council8, European Space Operations Centre9, Imperial College London10, University of Zurich11, University of Glasgow12, Polytechnic University of Catalonia13, Goddard Space Flight Center14
TL;DR: The Bayesian analysis framework is presented to process the planned system identification experiments designed for that purpose and focuses on the analysis strategies to predict the accuracy of the parameters that describe the system in all degrees of freedom.
Abstract: The main goal of LISA Pathfinder (LPF) mission is to estimate the acceleration noise models of the overall LISA Technology Package (LTP) experiment on-board. This will be of crucial importance for the future space-based Gravitational-Wave (GW) detectors, like eLISA. Here, we present the Bayesian analysis framework to process the planned system identification experiments designed for that purpose. In particular, we focus on the analysis strategies to predict the accuracy of the parameters that describe the system in all degrees of freedom. The data sets were generated during the latest operational simulations organised by the data analysis team and this work is part of the LTPDA Matlab toolbox.
3 citations
TL;DR: In this article, a statistical procedure for the analysis of time-frequency noise maps is presented and applied to LISA Pathfinder mission synthetic data, which is based on the Kolmogorov-Smirnov like test that is applied to the analysis for detecting non-stationary features in a noise time series produced with the spectrogram technique.
Abstract: A statistical procedure for the analysis of time-frequency noise maps is presented and applied to LISA Pathfinder mission synthetic data. The procedure is based on the Kolmogorov-Smirnov like test that is applied to the analysis of time-frequency noise maps produced with the spectrogram technique. The influence of the finite size windowing on the statistic of the test is calculated with a Monte Carlo simulation for 4 different windows type. Such calculation demonstrate that the test statistic is modified by the correlations introduced in the spectrum by the finite size of the window and by the correlations between different time bins originated by overlapping between windowed segments. The application of the test procedure to LISA Pathfinder data demonstrates the test capability of detecting non-stationary features in a noise time series that is simulating low frequency non-stationary noise in the system.
1 citations
European Space Agency1, Max Planck Society2, Paris Diderot University3, Imperial College London4, University of Trento5, Airbus Defence and Space6, University of Birmingham7, ETH Zurich8, Institut de Ciències de l'Espai9, European Space Operations Centre10, University of Zurich11, University of Glasgow12, Polytechnic University of Catalonia13, Goddard Space Flight Center14
TL;DR: In this paper, a new technical simulator for the eLISA mission, based on state space modeling techniques and developed in MATLAB, is presented, which computes the coordinate and velocity over time of each body involved in the constellation, taking into account the different disturbances and actuations.
Abstract: We present a new technical simulator for the eLISA mission, based on state space modeling techniques and developed in MATLAB. This simulator computes the coordinate and velocity over time of each body involved in the constellation, i.e. the spacecraft and its test masses, taking into account the different disturbances and actuations. This allows studying the contribution of instrumental noises and system imperfections on the residual acceleration applied on the TMs, the latter reflecting the performance of the achieved free-fall along the sensitive axis. A preliminary version of the results is presented.