December 1, 2017, 1:00 pm - 2:00 pm
December 1, 1:00 pm - 2:00 pm
CUAD: Constellation for Upper Atmosphere Dynamics
Larry Gordley, GATS Inc
The dynamical coupling of lower to upper atmosphere has become an intense research topic. It is now quite clear that the lower atmosphere continuously imprints its dynamical state on the upper atmosphere in the form of winds and waves. These dense lower atmosphere systems propagate their signature into the thin upper atmosphere at increasing magnification, like tsunamis coming ashore. This produces waves and winds that, if observed, could be used not only to reveal their effects on the ITM, but help observe and forecast the evolution of lower atmosphere weather.
Directly observing these dynamical features from orbit is a challenge due to their small scales and rapid time evolution. Sensors that observe the atmosphere through occultation or other limb observations (ex: GPS-RO and thermal imagers) are inherently limited to resolutions of 100 to 200 km or more in the horizontal. As a result, wave field observations are smeared in time and space to the point of limited value to forecasting. But, if these upper atmosphere signatures could be resolved, it has been shown by a variety of groups that those wave and wind fields could act as powerful boundary conditions on forecast models. We show that new and enabling technologies, and some novel observation techniques, now make it possible to observe these parameters at resolutions required to fill this measurement deficiency. We know of no current or planned system that could achieve the capabilities or low cost of the CUAD approach. The CUAD mission is to observe upper atmosphere dynamics on a global scale at a resolution sufficient to resolve the dynamical connection of lower to upper atmosphere. This can now be accomplished with simple static broadband emission imagers, implemented with a four-sensor approach that provides a novel system calibration advantage. The first sensor is a gas filtered broadband nadir emission imager, HATS TM (High Altitude Thermal Sounder). The second is a simple broadband limb emission radiometer LCER TM (Limb CO2 Emission Radiometer). The third is a gas filtered limb emission radiometer, DWTS TM (Doppler Wind and Temperature Sounder, Gordley, 2011). The fourth is a star field limb imager, TStar TM (Temperature sounder using Star field images). These 4 imagers have a unique synergistic connection that enables the elimination of on-board calibration systems. Also, each sensor, though new in its implementation, has conceptual space heritage that will be discussed. We also show results of rigorous performance estimates, and describe how modern detector FPAs, satellite bus ADCS, processor power and downlink bandwidth have come together to enable a complete system calibration anchored to temperature and pressure profiles derived from occulting star field images. This both simplifies the hardware and insures reliable observation of long-term trends. The talk will conclude with a list of major CUAD challenges and research needed for their solutions. Gordley, L. L., Benjamin T. Marshall, "Doppler Wind and Temperature Sounder: A new approach using gas filter correlation radiometry", JARS, Vol 5, 2011.