Developing a portable gas imaging camera using highly tunable active-illumination and computer vision.

We have developed a portable gas imaging camera for identifying methane leaks in real-time. The camera uses active illumination from distributed feedback InGaAs laser diodes tuned to the 1653 nm methane absorption band. An InGaAs focal plane sensor array images the active illumination. The lasers are driven off resonance every alternate frame so that computer vision can extract the gas data. A colour image is captured simultaneously and the data is superimposed to guide the operator. Image stabilisation has been employed to allow detection with a moving camera, successfully imaging leaks from mains pressure gas supplies at a range of up to 3 m and flow rates as low as 0.05 L min-1.