Elimination of Clock Jitter Noise in Spaceborn Laser Interferometers

TL;DR

This paper presents time-domain algorithms that effectively cancel clock jitter noise in space-based laser interferometers, improving the accuracy of gravitational wave detection despite spacecraft motion and Doppler shifts.

Contribution

It introduces a novel set of time-domain algorithms that eliminate clock jitter noise without the singularities of previous frequency-domain methods, enhancing space gravitational wave detector performance.

Findings

Exact cancellation of clock jitter noise achieved

Avoidance of singularities present in earlier algorithms

Practical implementation aspects addressed

Abstract

Space gravitational wave detectors employing laser interferometry between free-flying spacecraft differ in many ways from their laboratory counterparts. Among these differences is the fact that, in space, the end-masses will be moving relative to each other. This creates a problem by inducing a Doppler shift between the incoming and outgoing frequencies. The resulting beat frequency is so high that its phase cannot be read to sufficient accuracy when referenced to state-of-the-art space-qualified clocks. This is the problem that is addressed in this paper. We introduce a set of time-domain algorithms in which the effects of clock jitter are exactly canceled. The method employs the two-color laser approach that has been previously proposed, but avoids the singularities that arise in the previous frequency-domain algorithms. In addition, several practical aspects of the laser and clock noise cancellation schemes are addressed.