Multi-Frequency CW Fiber Laser-Lidar Suite for the ASCENDS Mission
Michael
Dobbs, ITT Space Systems, mike.dobbs@itt.com
(Presenting)
Jeremy
Dobler, ITT Space Systems, jeremy.dobler@itt.com
Jay
Overbeck, ITT Space Systems, jay.overbeck@itt.com
Berrien
Moore, Climate Central & Unversity of New Hamsphire,, berrien.moore@unh.edu
Edward
Browell, NASA LaRC, edward.v.browell@nasa.gov
Fenton
Harrison, NASA LaRC, fenton.w.harrison@nasa.gov
T.S.
Zaccheo, Atmosphere Environmental Research Inc, szaccheo@aer.com
H. E.
Snell, Atmosphere Environmental Research Inc, hsnell@aer.com
A unique, single-beam, modulated continuous-wave laser absorption spectroscopy instrument has been developed, validated and is fully operational for providing accurate retrievals of atmospheric carbon dioxide (CO2). The transmitter consists of a modulated continuous-wave fiber transmitter which simultaneously transmits all required wavelengths. The receiver consists of a low-noise HgCdTe APD detector whose output is demodulated with a synchronous narrowband receiver, which performs detection and wavelength separation; using digital communication methods in lieu of complex optical elements. The narrow-band detection method is superior to direct detection and achieves very high signal-to-noise ratios at a power-aperture product which is compatible with small to medium missions. This mature TRL 6 system achieves a mission enabling SNR per $-kg-watt-m3. A prototype instrument suite and high fidelity simulation model have been constructed and validated through several years of ground, field and airborne testing. Rapid and significant variations in the surface reflectance observed during these field tests have demonstrated a significant and unique advantage of this technique’s ability to simultaneously transmit all the wavelengths, resulting in these variations being truly common mode. The instrument suite has recently been extended to include the collection of column pressure via an O2 feature and the precision measurement of range to surface and clouds. This poster will focus on details regarding the instrument suite and its ability to meet the scientific requirements of the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission as stated in the U.S. National Research Council's report entitled Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond.
NASA Carbon Cycle & Ecosystems Active Awards Represented by this Poster: