University of California, Riverside physicists have developed a thermal-imaging method that could help the LIGO A+ gravitational-wave detectors operate closer to their intended sensitivity. Increasing the amount of circulating laser power can reduce photon shot noise, but it also increases the heat absorbed by the mirrors. LIGO already uses thermal compensation equipment and wavefront sensors, while researchers are also developing new mirror coatings and adaptive optics. Earlier UC Riverside work described a front-surface heating system designed to reshape LIGO mirrors, but a correction system needs a reliable signal showing how much heat to apply and where. From that map, the algorithm estimates the absorbed laser power, the beam’s position on the mirror, and the power delivered by each actuator.