High altitude thermal sounding using doppler modulated gas correlation

Larry L. Gordley, Benjamin T. Marshall, Martin J. McHugh, Dave Fritts, Chad Fish
2010 2010 IEEE International Geoscience and Remote Sensing Symposium  
INTRODUCTION This paper describes an important new measurement technique for high altitude thermal sounding (HATS), based on the Doppler modulated gas correlation (DMGC) approach. HATS measurements can potentially provide global temperature fields from cloud-top to 95 km at unprecedented spatial resolution. When assimilated into numerical weather models, these measurements can dramatically enhance forecast accuracy. HATS will enable prediction of the structure and effects of gravity waves on
more » ... gravity waves on the lower and upper atmosphere, including their transport of energy and momentum, generation of turbulence, and their influence on plasma instabilities in the ionosphere. Gravity waves play a major role in determining the circulation, thermal structure, and temporal and spatial variability of stratosphere and mesosphere, and their effects extend well into the thermosphere[1]. The studies presented here confirm the measurement proof-of-concept and identify the technique's potential in next-generation sensors for atmospheric dynamics forecasting. CURRENT STATE OF TECHNOLOGY Atmospheric thermal sounding is routinely accomplished by observing emission in multiple spectral intervals of varying absorption strengths. Radiation received by a down-looking spacecraft emanates from various depths in the atmosphere. To infer the temperature at a specific altitude, the instrument must measure and distinguish emission that predominantly emanates from that altitude. However, spectral absorption lines from gases at high altitude are very narrow due to their lack of pressure broadening. For example, the CO 2 emission lines near 15 m require a resolution of 0.002 cm -1 or better. Thermal microwave and infrared sounding using current technology (AIRS[2], GOES[3], AMSU[4]) has proven successful, but only with moderate spatial resolution and not above the mid-stratosphere, as illustrated in Figure 1 .
doi:10.1109/igarss.2010.5651438 dblp:conf/igarss/GordleyMMFF10 fatcat:uatgwkbvvzct3nlgg43aapvrxa