Description: Proposed here is a next generation Compact All Sky Interferometric Doppler Imager (CASIDI) capable of measuring a thermospheric wind field every few minutes, with a precision of 10s of m/s. The ability to measure the wind field two dimensionally over the visible thermosphere will provide greater measurement of gravity waves, energy transport, and interaction between the ionosphere and thermosphere. The proposed sensor addresses key science goals in the Heliophysics Decadal Survey [NRC, 2013]. The first is to “Determine the dynamics and coupling of Earth’s magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs.” The Decadal Survey underscored the importance of the Magnetosphere-Ionosphere-Thermosphere (MIT) system by stating “Understanding ionosphere-thermosphere interactions is a major area of inquiry, especially during geomagnetic storms.” The ionosphere exhibits significant day-to-day variability, which can seriously degrade important technological systems. Lack of ionospheric data, especially over the oceans, hinders scientific progress, and degrades the quality of existing nowcasting and forecasting systems. Ion-neutral coupling is a fundamental process that drives the evolution of the ionosphere and thermosphere. Recent observations of small-scale irregularities have been linked to neutral wind variability. Variations in neutral winds can drive complex and large-scale variability in the ionosphere. In addition to the sensor, a rapid manufacturing technique for the interferometer itself has been demonstrated. The combination of both the sensor and a vertically integrated manufacturing methodology will allow for lower cost and faster production of these sensors, thus enabling not only deployments in arrays but also on buoys and autonomous sea-going vehicles. Etalons manufactured with this technique will have applications well outside of Heliophysics.

Benefits: The CDI as a standalone sensor can provide thermospheric wind maps that are needed by the Space Weather community. Specifically, CASIDI can aid in understanding the Sun-atmosphere interaction region of Earth and its dynamical response to external and internal influences. Over time, data from CDI will be important in developing a near-real-time predictive capability for quantifying the impact of dynamical processes at the Sun on human activities and in Earth’s ionosphere.

Access to global wind maps from one or more CASIDI instruments will significantly improve the specification and forecast of ionospheric responses to solar and geomagnetic disturbances. This improvement provides direct societal benefits due to optimized operation of communication, navigation, and surveillance systems. The data from CASIDI will also provide vital data for scientific studies.