Demonstration of quantum-enhanced rangefinding robust against classical jamming.

We demonstrate a quantum-enhanced lidar capable of performing confident target detection and rangefinding in the presence of strong, time-varying classical noise whilst operating with over five orders of magnitude separation between signal and background levels and target reflectivities down to -52 dB. We use a log-likelihood-based framework to introduce a new protocol for dynamic background tracking, verifying resilience of our system to both fast- and slow-modulation jamming in regimes where a classical illumination-based system fails to find a target. These results demonstrate the advantage of exploiting quantum correlations for lidar applications, providing a clear route to implementation in real-world scenarios.