HR: 15:10h
AN: A53G-05 [Abstracts]
TI: Precise Measurement of Carbon Dioxide Column by Passive Ground Based Sensor
AU: * HEAPS, W S
EM: William.S.Heaps@nasa.gov
AF: NASA Goddard Space Flight Center, Code 554, Greenbelt, MD 20771, United States
AU: WILSON, E L
EM: Emily.L Wilson@nasa.gov
AF: NASA Goddard Space Flight Center, Code 554, Greenbelt, MD 20771, United States
AU: GEORGIEVA, E
EM: egeorgie@pop500.gsfc.nasa.gov
AF: University of Maryland, Baltimore County, 1000 Hilltop Circle, Bal;timore, MD 21250, United States
AB:
Over the past four years we have developed a family of differential radiometers based upon the Fabry-Perot
interferometers that exhibit very great sensitivity to changes in the atmospheric column of carbon dioxide, oxygen,
and water vapor. Our instruments employ a solid Fabry-Perot etalon that is tuned to the proper wavelength by
changing its temperature. The thickness of the etalon has been selected so that its multiple pass bands align
with regularly space absorption features of the molecule under investigation. Using multiple absorption features
improves the optical throughput of the instrument and improves the stability of the instrument response with
respect to environmental changes. We are presently working to extend this technique to the carbon 13 isotope of
carbon dioxide and to methane. Our instruments are intrinsically rugged and can be fabricated in a small
package at relatively low cost.. As such they hold promise for widespread use in ground based networks for
calibration and validation of satellite instruments such as OCO and GOSAT. Results will be presented for long
term ground based operations of these systems. The effects of atmospheric scattering, pointing errors, pressure
broadening and temperature effects will be discussed with regard to achieving precision better than .5% required
for validation of carbon dioxide column measured from space. Finally we will outline the approach for extension of
this methodology to additional molecular species of interest.
DE: 0394 Instruments and techniques
DE: 1640 Remote sensing (1855)
DE: 1694 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting