Demonstration of Time Delay Interferometry and Spacecraft Ranging in a Space-based Gravitational Wave Detector using the UF-LISA Interferometry Simulator

摘要

Space-based gravitational-wave observatories such as the Laser InterferometerSpace Antenna (LISA) use time-shifted and time-scaled linear combinations ofdifferential laser-phase beat signals to cancel the otherwise overwhelminglaser frequency noise. Nanosecond timing precision is needed to accurately formthese Time-Delay Interferometry (TDI) combinations which defines a ~1 meterrequirement on the inter-spacecraft ranging capability. The University ofFlorida Hardware-in-the-loop LISA Interferometry Simulator (UFLIS) has beenused to test Time-Delay Interferometry in a configuration which incorporatesvariable delays, realistic Doppler shifts, and simulated gravitational-wavesignals. The TDI 2.0 combinations are exploited to determine the time-changingdelays with nanosecond accuracy using a TDI-ranging reference tone. Thesevariable delays are used in forming the TDI combinations to achieve the LISAinterferometry sensitivity resulting from 10 orders of magnitude laserfrequency noise cancellation.