An acousto-optic tunable filter enhanced CO{sub 2} lidar atmospheric monitor

Conference · Tue Dec 31 00:00:00 EST 1996

OSTI ID:466736

Taylor, L H; Suhre, D R; Mani, S S ^[1]

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1. and others

The atmospheric monitor conceptual design is based on a pulsed CO{sub 2} laser. The narrow laser lines provide high spectral selectivity in the 9-11 {mu}m region, within the 8-14 {mu}m ``fingerprint`` region where most large molecules have unique spectral absorption signatures. Laser power has been chosen so that topological objects, e.g., trees or buildings, as far as 4 km can be used as backreflectors, but the laser intensity is sufficiently low that the laser beam is eye-safe. Time-of-flight measurements give the distance to the topological reflector. The lidar system is augmented with an acousto-optic tunable filter (AOTF) which measures the thermal emission spectra from 3 to 14 {mu}m with a 3 cm{sup -1} passband. Sensitivity to narrow emission lines is enhanced by derivative spectroscopy in which the passband of the AOTF is dithered via the rf drive. Path-averaged concentrations are determined from the emission intensity and laser- determined range.

• Research Organization: Northrop Grumman Corp., Pittsburgh, PA (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)
• DOE Contract Number: AR21-95MC32087
• OSTI ID: 466736
• Report Number(s): DOE/MC/32087-97/C0779; CONF-9611163-1; ON: DE97051967; TRN: 97:010208
• Resource Relation: Conference: Optical sensing for environmental and process monitoring conference, Dallas, TX (United States), 6-8 Nov 1996; Other Information: PBD: [1996]
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
40 CHEMISTRY
54 ENVIRONMENTAL SCIENCES
COVER GAS
AIR POLLUTION MONITORING
RADIOACTIVE WASTE STORAGE
VAPORS
FLAMMABILITY
TOXIC MATERIALS
ORGANIC COMPOUNDS
OPTICAL RADAR
TANKS
RADIOACTIVE WASTE FACILITIES
VENTS
ABSORPTION SPECTROSCOPY
LASER SPECTROSCOPY
REAL TIME SYSTEMS
UNDERGROUND STORAGE