Characterising the performance of a drone-mounted real-time methane imaging system.

We demonstrate a methane gas imaging system mounted to an unmanned aerial vehicle (UAV) that is shown to perform real-time detection at distances up to 10m whist airborne. Laser diodes that switch between on- and off- resonance with a methane absorption line are used to flood-illuminate a scene. The scene is imaged with an infrared InGaAs camera and the differential of the on-resonance and off-resonance back-scatter images are used to reveal the gas distribution. The performance of the system was characterised against a range of back-scatter surfaces, showing promising applicability to realistic gas sensing environments. We demonstrate that the system is capable of detecting a gas concentration of 5000 ppm.metre up to a range of 13.6m.