# Post-processing subtraction of tilt-to-length noise in LISA in the presence of gravitational wave signals

**Authors:** Marie-Sophie Hartig, Sarah Paczkowski, Martin Hewitson, Gerhard Heinzel, Gudrun Wanner  
**arXiv:** [2411.14191](https://arxiv.org/abs/2411.14191)  
**Date:** 2024-11-21  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2411.14191v2/

## Key points

- The Laser Interferometer Space Antenna (LISA) is the first space-based observatory for detecting gravitational waves in the frequency range of 0.1 mHz to 1 Hz.
- Tilt-to-length (TTL) coupling is a significant source of noise in LISA, caused by angular jitter transmitted into interferometric length readout from spacecraft movements.
- Current strategy involves subtracting TTL noise during post-processing without compromising the accuracy of GW signal detection.
- Study using simulated LISA data showed that subtracting TTL noise did not significantly impact the quality or characteristics of GW signals, emphasizing accurate distinction between TTL coupling and genuine GW signals for effective noise modeling.
- Acknowledgments to funding sources like Deutsches Zentrum für Luft- und Raumfahrt (DLR), Deutsche Forschungsgemeinschaft (DFG), and German Academic Exchange Service (DAAD) for support, along with collaborations with clusters like QuantumFrontiers and PhoenixD for scientific exchange opportunities.
- Feasibility of post-processing subtraction of TTL noise in LISA can enhance overall data quality and reliability in future space-based GW observations.

## Summary

The Laser Interferometer Space Antenna (LISA) is poised to become the first space-based observatory for detecting gravitational waves (GWs) in the frequency range of 0.1 mHz to 1 Hz. The success of these measurements relies on effectively suppressing various instrument noises, with tilt-to-length (TTL) coupling emerging as a significant source of noise in LISA. TTL coupling refers to the transmission of angular jitter, primarily originating from spacecraft movements, into the interferometric length readout. To address this issue, the current strategy involves subtracting TTL noise during post-processing while ensuring that it does not compromise the accuracy of GW signal detection. A recent study using simulated LISA data and examining four distinct types of GW signals demonstrated that subtracting TTL noise did not significantly impact the quality or characteristics of the GW signals. This finding highlights the importance of accurately distinguishing between TTL coupling and genuine GW signals within the same readout to facilitate effective noise modeling. Acknowledgments are extended to funding sources such as Deutsches Zentrum für Luft- und Raumfahrt (DLR), Deutsche Forschungsgemeinschaft (DFG), and German Academic Exchange Service (DAAD) for their support in enabling this research. Additionally, collaborations with clusters like QuantumFrontiers and PhoenixD have provided valuable scientific exchange opportunities. In conclusion, this study sheds light on the feasibility of post-processing subtraction of TTL noise in LISA amidst gravitational wave signal detection, emphasizing its potential for enhancing overall data quality and reliability in future space-based GW observations.