Spurious acceleration noise in spaceborne gravitational wave interferometers

Abstract

An important source of noise in the Laser Interferometer Space Antenna (LISA) is residual acceleration on the proof masses at the heart of the interferometer system. Two proof masses are carried by each sciencecraft in the LISA constellation, oriented along each of two laser links that are maintained between the distant partners in the constellation. Any change in the local mass distribution will create spurious forces on the individual proof masses which will have to be understood as part of the data analysis reduction. This paper considers the general case of accelerations on the individual proof masses in three dimensions for perturbing masses passing by a LISA sciencecraft with arbitrary velocity vectors and impact parameters. Encounters of this kind are impulsive, occurring over short time scales and appearing in the data record as bursts. The formalism is then applied in a few sample cases, including a meteor fly-by and a thruster maneuver.