An airborne infrared (IR) line-scanner and a Fourier transform infrared (FT-IR) spectrometer operating in the 3- 5micrometers and 8-12micrometers spectral regions provide a rapid wide- area surveillance capability. The IR scene containing target vapors is mapped remotely with the wide fields of view (FOV) multi-spectral IR line-scanner using 14 bands. The narrow FOV FT-IR spectrometer permits remote verification of target vapor plume contents within the IR scene. The IR image and FT-IR interferogram analysis supply a near real-time detection that provides visual monitoring of potential downwind vapor hazards. This capability is demonstrated using the target vapor methanol. An active mono-static FT-IR configuration furnishes ground-truth monitoring for methanol released from an industrial stack and a nearby ground-level area. The airborne and ground-truth results demonstrate the usefulness of this approach in alerting first responders to potential downwind vapor hazards from an accidental release.
Advances made over the past decade in multispectral and hyperspectral imaging systems, have led to a wide range of new remove sensing capabilities, including the ability to detect and image chemical vapors in the atmosphere. This sensor has application in the detection and monitoring of chemical weapons, as well as environmental pollution monitoring. Key to the continuing development of this technology is accurate and temporally stable radiometric calibration. This paper presents an overview of the system level radiometric calibration approach used for the SAFEGUARD multispectral infrared line scanner. This approach includes radiometric calibration of the sensor at the aperture, corrections for atmospheric effects and group truth validation.