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.
Equatorial spread-F (ESF), is mainly found within 20° of the magnetic equator and occurs at night. ESF frequently occurs when the eastward electric field is large, and when trans-equatorial neutral winds are small. ESF onset driven primarily by the electric field and on the neutral winds stems from the importance of these terms in the growth rate of the Rayleigh-Taylor instability, which drives the ESF phenomenon Sultan, [1996]. While Gravity waves may seed perturbations that set off an instability, Fritts et al. [2009] demonstrated that F-region eastward neutral winds at sunset play the dominant role in triggering ESF. New neutral wind measurements will further our understanding of ionospheric irregularities and their formation.
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.”
In addition to the sensor, a rapid manufacturing technique for the interferometer itself is also explored. 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.