Remote imaging of controlled gas releases using active and passive infrared imaging systems

The results of field tests of an active backscatter absorption gas imaging (BAGI) system and a passive imager based on a Ga:Si infrared focal-plane array are presented. Both imagers allow real-time video imaging of gas emissions. The former system images gases through their attenuation of backscattered laser illumination; the latter images gases through temperature or emissivity differences. The results represent the first side-by-side comparison of an active and passive imager and the first BAGI field trial involving the imaging of plumes of controlled concentration and dimension.