Uploaded July 2022 | Updated September 2026, 1 hour ago
Laser frequency noise (LFN) due to unequal separations between spacecraft is the loudest source of noise expected in the LISA mission at 107 times greater magnitude than the typical strain expected for LISA GW signals. Time-delay interferometry (TDI) suppresses LFN to an acceptable level by linearly combining measurements from individual spacecraft delayed by durations that correspond to their relative separations. Knowledge of the delay durations is crucial for TDI effectiveness, and it’s been shown that they can be estimated from the raw phasemeter data using fractional delay interpolation (FDI), allowing for TDI implementation during the post-processing of data (time-delay interferometric ranging, TDIR) once data is telemetered to Earth. This work performs TDIR using a Markov Chain Monte Carlo algorithm. Including TDIR parameters in the LISA data model as part of a "global fit" analysis pipeline produces GW inferences that are marginalized over uncertainty in the spacecraft separations. Here we extend previous studies to now use data simulated by LISA Instrument, and to estimate the time-dependent delay durations for the "2nd-generation'' TDI combinations that account for the orbital motion of the spacecraft. The potential for an independent reconstruction of the spacecraft orbits is also explored.
Authors:
Jessica Page (Presenting)
University of Alabama Huntsville, Huntsville, AL, USA
Laser frequency noise (LFN) due to unequal separations between spacecraft is the loudest source of noise expected in the LISA mission at 107 times greater magnitude than the typical strain expected for LISA GW signals. Time-delay interferometry (TDI) suppresses LFN to an acceptable level by linearly combining measurements from individual spacecraft delayed by durations that correspond to their relative separations. Knowledge of the delay durations is crucial for TDI effectiveness, and it’s been shown that they can be estimated from the raw phasemeter data using fractional delay interpolation (FDI), allowing for TDI implementation during the post-processing of data (time-delay interferometric ranging, TDIR) once data is telemetered to Earth. This work performs TDIR using a Markov Chain Monte Carlo algorithm. Including TDIR parameters in the LISA data model as part of a "global fit" analysis pipeline produces GW inferences that are marginalized over uncertainty in the spacecraft separations. Here we extend previous studies to now use data simulated by LISA Instrument, and to estimate the time-dependent delay durations for the "2nd-generation'' TDI combinations that account for the orbital motion of the spacecraft. The potential for an independent reconstruction of the spacecraft orbits is also explored.
Authors:
Jessica Page (Presenting)
University of Alabama Huntsville, Huntsville, AL, USA
