Calculation of aerosol backscatter from airborne continuous wave focused CO sub 2 Doppler lidar measurements. 2. Algorithm performance

Journal Article · Wed Mar 20 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/89JD00362· OSTI ID:5331151

Rothermel, J ^[1]; Bowdle, D A ^[2]; Vaughan, J M ^[3]

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1. NASA Marshall Space Flight Center, Huntsville, AL (USA)
2. Univ. of Alabama, Huntsville (USA)
3. Royal Signals and Radar Establishment, Worcestshire (England)

The performance of an algorithm to calculate aerosol backscatter coefficients, from measurements with an airborne continuous wave focused CO{sub 2} Doppler lidar, is described relative to flight hardware settings and operating characteristics, and theoretical considerations. The algorithm (described in paper 1) is used to analyze measurements by the Laser True Airspeed System (LATAS), operated by the Royal Signals and Radar Establishment (RSRE) and Royal Aircraft Establishment (RAE), United Kingdom. Under optimum signal conditions, backscatter signals are located unambiguously and the backscatter coefficients are accurately determined. Under marginal or subthreshold conditions, with a degraded system sensitivity, false alarms (mistaking noise for signal) occur. Parametric studies show that the false alarm rate under these conditions depends on the search window size and the signal-to-noise ratio (SNR) threshold for valid signals. Carefully selected diagnostic parameters are used to estimate the combined sensitivity of the flight hardware system and algorithm. Less than 1% of backscatter measurements for flights over approximately 5 years have been found to be below the measurement sensitivity when the LATAS flight hardware controls were set for optimum sensitivity.

• OSTI ID: 5331151
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:D3; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AEROSOLS
AIRCRAFT
ALGORITHMS
BACKSCATTERING
CALCULATION METHODS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
COLLOIDS
DISPERSIONS
DOPPLER EFFECT
MATHEMATICAL LOGIC
MEASURING INSTRUMENTS
OPTICAL RADAR
OXIDES
OXYGEN COMPOUNDS
PARAMETRIC ANALYSIS
PERFORMANCE
RADAR
RANGE FINDERS
SCATTERING
SIGNAL-TO-NOISE RATIO
SOLS