Detection of gaseous plumes in airborne hyperspectral imagery

Abstract

The thermal hyperspectral sensor Hyper-Cam was mounted on a light aircraft and measured continuous releases of several atmospheric tracers from a height of 2 km. A unique detection algorithm that eliminates the need for clear background estimation was operated over the acquired data with excellent detection results. The data-cubes were acquired in a "target mode", which is a unique method of operation of the Hyper-Cam sensor. This method provides multiple views of the plume which can be exploited to enhance the detection performance. These encouraging results demonstrate the utility of airborne LWIR hyperspectral imaging for efficient detection and mapping of effluent gases for environmental monitoring.

Standoff Infrared Measurements of Chemical Plume Dynamics in Complex Terrain Using a Combination of Active Swept-ECQCL Laser Spectroscopy with Passive Hyperspectral Imaging

“…The gas measured and spectral analysis procedure will also influence the results. Previous measurements of SF 6 plumes using Telops instrumentation have been reported [29,[35][36][37], and in Hirsch and Agassi [37], a detection limit for SF 6 was reported as 30.5 mg/m 2 (5 ppm × m) with a 4 s measurement time. The results obtained here using the Telops LWIR-HSI system showed a NECD of 0.4 ppm × m, obtained with an integration time of 7 s, which is similar to values previously reported considering measurement differences.…”

“…The first method of detection used a passive LWIR imaging FTIR spectrometer. This hyperspectral imager (Telops Hyper-Cam LW) [29,[34][35][36][37] was used to observe the spatial and temporal dynamics of plumes as they propagated away from the release point. The LWIR hyperspectral imager (LWIR-HSI) operates by spectrally resolving an image of thermal radiation from a scene as a function of time.…”

A hyperspectral thermal imager based on a low order scanning Fabry-Pérot interferometer

“…made it possible to classify different kinds of plastics [4], to detection of apple scab disease [5], and to estimate degree of polymerization in cotton fabrics [6] to name a few. Additionally, in the long-wave infrared (LWIR) regime, the fundamental vibrational states of many different materials can be observed enabling applications such as remote sensing of minerals [7] and gaseous plumes [8]. The LWIR range of the electromagnetic spectrum is also often associated with thermal radiation which is why most thermal cameras operate in this region.…”