Sensor noise in LISA Pathfinder: An extensive in-flight review of the angular and longitudinal interferometric measurement system

In a previous article, we have reported on the first subpicometer interferometer flown in space as part of ESA’s LISA Pathfinder mission, and have shown the residual sensor noise to be on the level of 32.0$^{+2.4}_{−1.7}$ fm/√Hz. This review provides a deeper and more complete overview of the full system and its interferometric mission performance under varying operational conditions, allowing a much more detailed view on the noise model. We also include the optical measurements of rotations through differential wave front sensing (DWS), which reached a sensitivity of as good as 100 prad/√Hz. We present more evidence for the long-term stability of the interferometric performance and components. This proves a solid foundation for future interferometry in space such as the LISA mission.