Scientists at the international LIGO, Virgo and KAGRA (LVK) gravitational wave observatory collaboration have employed the technique, which they call astrophysical calibration, to use gravitational-wave signals to measure the response of their incredibly sensitive instruments.

It enables them to ensure that they can clearly "hear" the sounds of colossal cosmic events like the collision of black holes, even when one gravitational wave detector is slightly out of tune. This is crucial to accurately interpret the signals and find their source location.

By combining signals from other detectors with precise predictions from the laws of gravity, researchers can identify and account for subtle distortions in the data. The process is similar to how music‑production software such as Auto-Tune can correct a singer's errant pitch to meet the intended note in a melody.

In a new paper published in the journal Physical Review Letters, LVK researchers demonstrate how they turned the challenge of analyzing data collected from two gravitational wave signals detected when LIGO Hanford was up and running, but performing below its usual standard, into an opportunity to improve the collaboration's ability to analyze data. The paper is titled "GW240925 and GW250207: Astrophysical Calibration of Gravitational-wave Detectors."

The results could help future observing runs of the international network of LVK detectors in the U.S., Italy and Japan ensure that they produce the most reliable results, even when the circumstances of the detection are less than ideal.