Experimental verification of intersatellite clock synchronization at LISA performance levels

TL;DR

This paper experimentally verifies a clock synchronization scheme for LISA's space-based gravitational wave observatory, demonstrating it can achieve the required precision for accurate interferometry.

Contribution

It presents an experimental validation of a clock synchronization method suitable for LISA, including data processing techniques applicable to real mission data.

Findings

Achieved clock synchronization at LISA performance levels

Validated the synchronization scheme using a hexagonal optical bench

Discussed noise coupling mechanisms affecting synchronization

Abstract

The Laser Interferometer Space Antenna (LISA) aims to observe gravitational waves in the mHz regime over its 10-year mission time. LISA will operate laser interferometers between three spacecrafts. Each spacecraft will utilize independent clocks which determine the sampling times of onboard phasemeters to extract the interferometric phases and, ultimately, gravitational wave signals. To suppress limiting laser frequency noise, signals sampled by each phasemeter need to be combined in postprocessing to synthesize virtual equal-arm interferometers. The synthesis in turn requires a synchronization of the independent clocks. This article reports on the experimental verification of a clock synchronization scheme down to LISA performance levels using a hexagonal optical bench. The development of the scheme includes data processing that is expected to be applicable to the real LISA data with minor modifications. Additionally, some noise coupling mechanisms are discussed.