BAGI: a technique for the detection and tracking of large gas clouds

Conference · Tue Feb 01 04:00:00 EST 1983

OSTI ID:6288313

McRae, T G

For the past six years the Liquefied Gaseous Fuels (LGF) Spill Effects Program at the Lawrence Livermore National Laboratory (LLNL) has been studying the possible hazards associated with large-scale spills of hazardous materials. This effort has focused primarily on modeling and measurement of the dispersion of large, heavier-than-air gas clouds. A need was discovered for the development of a system which would allow the remote detection and tracking of these large hazardous gas clouds. A passive infrared (IR) imaging system for use in monitoring liquefied natural gas (LNG) vapor cloud dispersion and vapor cloud combustion dynamics is being developed. The heart of the imaging system is the Inframetrics, Inc., Model 210 Fast Scan IR Thermal Imager. This is a two-wavelength, broadband system which when mounted in a helicopter, and with appropriate choice of interference filters, provides images of the dispersing gas cloud. These images were used to augment the LFG Program's surface gas measurement data taken during the Burro Series tests at the Naval Weapons Center (NWC), China Lake, CA. This system relies on the thermal radiation from the ground to produce a background image and the absorption bands of methane, ethane, and propane to attenuate this background image when the vapor is present. The system demonstrated the ability to image the LNG vapor cloud from an altitude of 1 km for gas concentrations down to about 1%. The BAGI technique is based on the radiation augmentation of the field of view of an imaging device by laser radiation corresponding to an absorption line of the gas species to be detected. Schematic representation of several BAGI systems as proposed both for leak detection and the tracking of a hazardous gas cloud are shown.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6288313
• Report Number(s): UCRL-88781; CONF-830321-2; ON: DE83008405
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030800* -- Natural Gas-- Environmental Aspects
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AERIAL MONITORING
CLOUDS
DISTRIBUTION
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GAS SPILLS
GASES
IMAGES
INFRARED SPECTRA
INFRARED THERMOGRAPHY
LEAK DETECTORS
LIQUEFIED GASES
LIQUEFIED NATURAL GAS
MEASURING METHODS
MONITORING
NATURAL GAS
REMOTE SENSING
SPATIAL DISTRIBUTION
SPECTRA
THERMOGRAPHY