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| Titel |
Development and Validation of CO2 and O2 Laser Measurements for Future Active XCO2 Space Mission |
| VerfasserIn |
Edward Browell, Jeremy Dobler, F. Wallace Harrison, Berrien Moore III |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250056844
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| Zusammenfassung |
| This paper discusses the development and validation of a unique, multi-frequency,
intensity-modulated, laser absorption spectrometer (LAS) operating simultaneously in the
1.57-μm region for column CO2 measurements and in the 1.26-μm region for column O2
measurements. This laser system is under development for a future space mission to
determine the global distribution of regional-scale CO2 mixing ratio (XCO2) sources
and sinks, which is the objective of the NASA Active Sensing of CO2 Emissions
during Nights, Days, and Seasons (ASCENDS) mission. A prototype of this LAS
system, called the Multi-frequency Fiber Laser Lidar (MFLL), is being developed
by ITT and evaluated by the NASA Langley Research Center. The MFLL CO2
measurements have been flight tested in ten airborne campaigns since May 2005. MFLL O2
measurements using a Raman amplifier began ground testing in early 2010, and it is
being integrated with the CO2 measurement capability for combined CO2 and O2
measurements during flight tests this year. This paper describes the MFLL CO2 and O2
measurement concepts; discusses the most recent results from the 2010 flight tests of the
MFLL CO2 measurements and from ground tests of the O2 measurements; presents
the flight test plans for this year; and describes the MFLL space implementation
architecture.
A major ASCENDS flight test campaign was conducted on the NASA DC-8 during 6-18
July 2010, and the MFLL CO2 column measurements were evaluated as part of this
campaign. The MFLL system and associated in situ CO2 instrumentation were operated
on DC-8 flights over the Central Valley of California; the desert of southeastern
California/Nevada; the Pacific Ocean off of the Baja Peninsula; Railroad Valley,
Nevada; and the Department of Energy Atmospheric Radiation Measurement Central
Facility in Lamont, Oklahoma. Remote CO2 column measurements were made from
altitudes of 2.5 to 13 km, and in situ CO2 profiles were obtained on spirals from the
highest altitude on each flight to as low as 30 m at the center of the flight track.
Radiosondes were also launched in conjunction with these flights to constrain the
meteorological conditions for the validation of the MFLL CO2 column measurements. The
MFLL CO2 column measurement precision from 7 km AGL with 1-s (~150-m)
averaging was shown to be better than 0.2% ( |
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