NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Atmospheric CO2 Column Measurements with an Airborne Intensity-Modulated Continuous-Wave 1.57-micron Fiber Laser LidarThe 2007 National Research Council (NRC) Decadal Survey on Earth Science and Applications from Space recommended Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) as a mid-term, Tier II, NASA space mission. ITT Exelis, formerly ITT Corp., and NASA Langley Research Center have been working together since 2004 to develop and demonstrate a prototype Laser Absorption Spectrometer for making high-precision, column CO2 mixing ratio measurements needed for the ASCENDS mission. This instrument, called the Multifunctional Fiber Laser Lidar (MFLL), operates in an intensity-modulated, continuous-wave mode in the 1.57- micron CO2 absorption band. Flight experiments have been conducted with the MFLL on a Lear-25, UC-12, and DC-8 aircraft over a variety of different surfaces and under a wide range of atmospheric conditions. Very high-precision CO2 column measurements resulting from high signal-to-noise (great than 1300) column optical depth measurements for a 10-s (approximately 1 km) averaging interval have been achieved. In situ measurements of atmospheric CO2 profiles were used to derive the expected CO2 column values, and when compared to the MFLL measurements over desert and vegetated surfaces, the MFLL measurements were found to agree with the in situ-derived CO2 columns to within an average of 0.17% or approximately 0.65 ppmv with a standard deviation of 0.44% or approximately 1.7 ppmv. Initial results demonstrating ranging capability using a swept modulation technique are also presented.
Document ID
20140002525
Acquisition Source
Langley Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Dobler, Jeremy T.
(Exelis, Inc. Fort Wayne, IN, United States)
Harrison, F. Wallace
(NASA Langley Research Center Hampton, VA, United States)
Browell, Edward V.
(NASA Langley Research Center Hampton, VA, United States)
Lin, Bing
(NASA Langley Research Center Hampton, VA, United States)
McGregor, Doug
(Exelis, Inc. Fort Wayne, IN, United States)
Kooi, Susan
(Science Systems and Applications, Inc. Hampton, VA, United States)
Choi, Yonghoon
(Science Systems and Applications, Inc. Hampton, VA, United States)
Ismail, Syed
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
April 1, 2014
Publication Date
January 1, 2013
Subject Category
Meteorology And Climatology
Report/Patent Number
NF1676L-15864
Funding Number(s)
WBS: WBS 304029.01.04.05.02
Distribution Limits
Public
Copyright
Public Use Permitted.
No Preview Available