Details
| Original language | English |
|---|---|
| Article number | 045004 |
| Journal | Classical and quantum gravity |
| Volume | 42 |
| Issue number | 4 |
| Publication status | Published - 24 Jan 2025 |
Abstract
The coupling of the angular jitter of the spacecraft and their sub-assemblies with the optical bench and the telescope into the interferometric length readout will be a major noise source in the LISA mission. We refer to this noise as tilt-to-length (TTL) coupling. It will be reduced directly by realignments, and the residual noise will then be subtracted in post-processing. The success of these mitigation strategies depends on an accurate computation of the TTL coupling coefficients. We present here a thorough analysis of the accuracy of the coefficient estimation under different jitter characteristics, angular readout noise levels, and gravitational wave sources. We analyze in which cases the estimates degrade using two estimators, the common least squares estimator and the instrumental variables estimator. Our investigations show that angular readout noise leads to a systematic bias of the least squares estimator, depending on the TTL coupling coefficients, jitter and readout noise level, while the instrumental variable estimator converges to an unbiased result as the data set length increases. We present an equation that predicts the estimation bias of the least squares method due to angular readout noise.
Keywords
- gravitational waves, instrument noise, laser interferometer space antenna, performance analysis, tilt-to-length coupling
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physics and Astronomy (miscellaneous)
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In: Classical and quantum gravity, Vol. 42, No. 4, 045004, 24.01.2025.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Tilt-to-length coupling in LISA—uncertainty and biases
AU - Hartig, M. S.
AU - Marmor, J.
AU - George, D.
AU - Paczkowski, S.
AU - Sanjuan, J.
N1 - Publisher Copyright: © 2025 The Author(s). Published by IOP Publishing Ltd.
PY - 2025/1/24
Y1 - 2025/1/24
N2 - The coupling of the angular jitter of the spacecraft and their sub-assemblies with the optical bench and the telescope into the interferometric length readout will be a major noise source in the LISA mission. We refer to this noise as tilt-to-length (TTL) coupling. It will be reduced directly by realignments, and the residual noise will then be subtracted in post-processing. The success of these mitigation strategies depends on an accurate computation of the TTL coupling coefficients. We present here a thorough analysis of the accuracy of the coefficient estimation under different jitter characteristics, angular readout noise levels, and gravitational wave sources. We analyze in which cases the estimates degrade using two estimators, the common least squares estimator and the instrumental variables estimator. Our investigations show that angular readout noise leads to a systematic bias of the least squares estimator, depending on the TTL coupling coefficients, jitter and readout noise level, while the instrumental variable estimator converges to an unbiased result as the data set length increases. We present an equation that predicts the estimation bias of the least squares method due to angular readout noise.
AB - The coupling of the angular jitter of the spacecraft and their sub-assemblies with the optical bench and the telescope into the interferometric length readout will be a major noise source in the LISA mission. We refer to this noise as tilt-to-length (TTL) coupling. It will be reduced directly by realignments, and the residual noise will then be subtracted in post-processing. The success of these mitigation strategies depends on an accurate computation of the TTL coupling coefficients. We present here a thorough analysis of the accuracy of the coefficient estimation under different jitter characteristics, angular readout noise levels, and gravitational wave sources. We analyze in which cases the estimates degrade using two estimators, the common least squares estimator and the instrumental variables estimator. Our investigations show that angular readout noise leads to a systematic bias of the least squares estimator, depending on the TTL coupling coefficients, jitter and readout noise level, while the instrumental variable estimator converges to an unbiased result as the data set length increases. We present an equation that predicts the estimation bias of the least squares method due to angular readout noise.
KW - gravitational waves
KW - instrument noise
KW - laser interferometer space antenna
KW - performance analysis
KW - tilt-to-length coupling
UR - http://www.scopus.com/inward/record.url?scp=85216344232&partnerID=8YFLogxK
U2 - 10.1088/1361-6382/ada866
DO - 10.1088/1361-6382/ada866
M3 - Article
AN - SCOPUS:85216344232
VL - 42
JO - Classical and quantum gravity
JF - Classical and quantum gravity
SN - 0264-9381
IS - 4
M1 - 045004
ER -