HR: 09:45h
AN: A11F-08 [Abstracts]
TI: Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS)
AU: * Dobbs, M
EM: mike.dobbs@itt.com
AF: ITT Space Systems Division, 1919 West Cook Road, Fort Wayne, IN 46845, United States
AU: Dobler, J
EM: jermey.dobler@itt.com
AF: ITT Space Systems Division, 1919 West Cook Road, Fort Wayne, IN 46845, United States
AU: Moore, B
EM: b.moore@unh.edu
AF: University of New Hampshire, Institute for the Study of Earth, Oceans and Space
Morse Hall Suite 305
39 College Road, Durham, NH 03824, United States
AU: Browell, E
EM: Edward.V.Browell@nasa.gov
AF: NASA Langley Research Center, Atmospheric Sciences Research, Hampton, VA 23681,
United States
AU: Harrison, F W
EM: Fenton.W.Harrison@nasa.gov
AF: NASA Langley Research Center, Atmospheric Sciences Research, Hampton, VA 23681,
United States
AU: Snell, H
EM: nsnell@aer.com
AF: Atmospheric and Environmental Research Inc, 131 Hartwell Ave, Lexington, MA 02421,
United States
AB:
We have developed and is in the process of validating the in-flight performance of an airborne prototype of the
Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) payload.
The Team is partnership of ITT Space Systems Division, the NASA Langley Research Center, the University of
New Hampshire Institute for the Study of Earth, Oceans and Space, and Atmospheric and Environmental
Research Inc, The team has conducted several flights, the results of which have been used to fine tune the
configuration and operation of the instrument, the parameters for the forward modeling studies and the retrieval
algorithms.
The airborne instrument suite measures; a) the number density of CO2 in the column of air beneath the aircraft,
b) length of the column using a laser altimeter, and c) ambient air pressure and temperature. Within the next few
months we will have installed a 3rd lidar tuned to O2 for making a direct measurement of number density of O2.
The retrieval algorithm converts these measured parameters into column CO2 mixing ratio. The precision of the
lidar measurements are a function of the product of power-aperture-integration time. As installed today, the lidar
are configured to operate at the same received power level as baselined for an affordable LIDAR placed in low
earth orbit. ITT and NASA have run several mission formulation and trade studies which confirm the baseline
payload for ASCENDS meets the science requirement of 0.5% precision measurement of CO2 mixing ratio along
a 100km horizontal segment and fits the mass-power-volume constraints (with margin) for a Taurus class
payload. The established Technology Readiness Level 6 of the nearly commercial-off-the-shelf fiber transmitter
system ensures that the cost and schedule constraints can also be met with margin.
We will present the principals of operation of ITT's proprietary and patented lidar system for ASCENDS. The
modeled performance and the measured performance will also be discussed, along with an assessment of the
current technology readiness and planned activities for 2008.
DE: 1610 Atmosphere (0315, 0325)
DE: 1622 Earth system modeling (1225)
DE: 1640 Remote sensing (1855)
DE: 1694 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting