Adapting time-delay interferometry for LISA data in frequency

Bayle, Jean-Baptiste; Hartwig, Olaf; Staab, Martin

doi:10.1103/physrevd.104.023006

“…The most basic configuration can be thought of as a TDI-Michelson-Morley interferometer, where one constructs a response such as that in Equation (58). However, the great advantage of TDI is that it is possible to construct channels that suppress detector noise and enhance the signal [138]; this is a very active area of study [139][140][141][142][143][144]. For the purposes of this review, let us cite the TDI {X, Y, Z} set of channels, which are based on the Michelson-Morley style measurement in Equation (58), where nominally X is centered around spacecraft 1, referred to hereafter as S 1 ; Y around spacecraft 2, S 2 ; and Z around spacecraft 3, S 3 .…”

Section: Interdetector and Spatial Correlationsmentioning

confidence: 99%

Stochastic Gravitational-Wave Backgrounds: Current Detection Efforts and Future Prospects

Renzini

¹

,

Goncharov

²

,

Jenkins

³

et al. 2022

View full text Add to dashboard Cite

The collection of individually resolvable gravitational wave (GW) events makes up a tiny fraction of all GW signals that reach our detectors, while most lie below the confusion limit and are undetected. Similarly to voices in a crowded room, the collection of unresolved signals gives rise to a background that is well-described via stochastic variables and, hence, referred to as the stochastic GW background (SGWB). In this review, we provide an overview of stochastic GW signals and characterise them based on features of interest such as generation processes and observational properties. We then review the current detection strategies for stochastic backgrounds, offering a ready-to-use manual for stochastic GW searches in real data. In the process, we distinguish between interferometric measurements of GWs, either by ground-based or space-based laser interferometers, and timing-residuals analyses with pulsar timing arrays (PTAs). These detection methods have been applied to real data both by large GW collaborations and smaller research groups, and the most recent and instructive results are reported here. We close this review with an outlook on future observations with third generation detectors, space-based interferometers, and potential noninterferometric detection methods proposed in the literature.

show abstract

“…Here, the indices i, j, k are to be chosen from the set {1, 2, 3}, with i = j = k. The N isi ij (τ ), N rfi ij (τ ) and N tmi ij (τ ) terms denote an uncorrelated readout noise in each interferometer, while N δ ij (τ ) is the frequency shift due to test-mass displacement. We define the Dopplerdelay [26] Ḋτi ij as…”

Section: Simulation Model and Tdi Variable Construction A Interferome...mentioning

confidence: 99%

“…We perform TDI processing using frequency data following the prescriptions of [26], using only Doppler delay operators.…”

Section: B Tdi Combinationsmentioning

confidence: 99%

Time delay interferometry without clock synchronisation

Hartwig,

Bayle,

Staab

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Time-delay interferometry (TDI) is a data processing technique for LISA designed to suppress the otherwise overwhelming laser noise by several orders of magnitude. It is widely believed that TDI can only be applied once all phase or frequency measurements from each spacecraft have been synchronized to a common time frame. We demonstrate analytically, using as an example the commonly-used Michelson combination X, that TDI can be computed using the raw, unsynchronized data, thereby avoiding the need for an initial synchronization processing step and significantly simplifying the initial noise reduction pipeline. Furthermore, the raw data is free of any potential artifacts introduced by clock synchronization and reference frame transformation algorithms, which allows to operate directly on the MHz beatnotes. As a consequence, in-band clock noise is directly suppressed as part of TDI, in contrast to the approach previously proposed in the literature (in which large trends in the beatnotes are removed before the main laser-noise reduction step, and clock noise is suppressed in an extra processing step). We validate our algorithm with full-scale numerical simulations that use LISA Instrument and PyTDI and show that we reach the same performance levels as the previously proposed methods, ultimately limited by the clock sideband stability.

show abstract

“…The most basic configuration can be thought of as a TDI-Michelson-Morley interferometer, where one constructs a response such as that in Equation (58). However, the great advantage of TDI is that it is possible to construct channels that suppress detector noise and enhance the signal [139]; this is a very active area of study [140][141][142][143][144][145]. For the purposes of this review, let us cite the TDI {X, Y, Z} set of channels, which are based on the Michelson-Morley style measurement in Equation (58), where nominally X is centered around spacecraft 1, referred to hereafter as S 1 ; Y around spacecraft 2, S 2 ; and Z around spacecraft 3, S 3 .…”

Section: Interdetector and Spatial Correlationsmentioning

confidence: 99%

“…The links are then combined to form TDI channels, as detailed in Section 4.1. Basic LISA studies start from considering sets of three channels, where each channel is centered around one spacecraft; however, more sophisticated studies are already under way [139,141,357]. These channels produce a set of observations, which we can treat as timestreams for the purposes of this discussion (although these are effectively combined in post-processing and are not the read-out of the detector), X(t), Y(t), Z(t), as introduced in Section 4.1.…”

Section: Stochastic Searches With the Laser Interferometer Space Antennamentioning

confidence: 99%

Stochastic Gravitational-Wave Backgrounds: Current Detection Efforts and Future Prospects

Renzini¹,

Goncharov²,

Jenkins³

et al. 2022

Preprint

0

View full text Add to dashboard Cite

The collection of individually resolvable gravitational wave (GW) events makes up a tiny fraction of all GW signals that reach our detectors, while most lie below the confusion limit and are undetected. Similarly to voices in a crowded room, the collection of unresolved signals gives rise to a background that is well-described via stochastic variables and, hence, referred to as the stochastic GW background (SGWB). In this review, we provide an overview of stochastic GW signals and characterise them based on features of interest such as generation processes and observational properties. We then review the current detection strategies for stochastic backgrounds, offering a ready-to-use manual for stochastic GW searches in real data. In the process, we distinguish between interferometric measurements of GWs, either by ground-based or space-based laser interferometers, and timing-residuals analyses with pulsar timing arrays (PTAs). These detection methods have been applied to real data both by large GW collaborations and smaller research groups, and the most recent and instructive results are reported here. We close this review with an outlook on future observations with third generation detectors, space-based interferometers, and potential noninterferometric detection methods proposed in the literature.

show abstract

Adapting time-delay interferometry for LISA data in frequency

Cited by 25 publications

References 24 publications

Stochastic Gravitational-Wave Backgrounds: Current Detection Efforts and Future Prospects

Stochastic Gravitational-Wave Backgrounds: Current Detection Efforts and Future Prospects

Time delay interferometry without clock synchronisation

Stochastic Gravitational-Wave Backgrounds: Current Detection Efforts and Future Prospects

Contact Info

Product

Resources

About