A Sounding Rocket experiment to Validate Ultraviolet Remote Sensing of the Upper Atmosphere and Ionosphere

Despite decades of observations and interpretations of ultraviolet airglow, advancing the derivation of physical parameters of the ionosphere and atmosphere beyond the current successes presents difficult challenges due to the lack of comprehensive understanding of the fundamental detailed physics that surrounds the associated airglow emission process. The daytime thermosphere, while better characterized than the ionosphere, is still subject to uncertainties caused by the need for somewhat ad-hoc modeling using a multi-step process that creates the UV airglow emissions. The state of the field for the daytime ionosphere is currently based on only a few dozen profiles obtained from sounding rocket and satellite missions, none of which were designed to obtain the necessary comprehensive set of measurements. We have designed a sounding rocket experiment that will validate extreme and far ultraviolet (EUV/FUV) remote sensing of the ionosphere and thermosphere during day time. The sounding rocket data will be coordinated with simultaneous observations by an Incoherent Scatter Radar which will provide altitude profiles of daytime electron density, ion composition, electron and ion temperatures, and ion drifts due to winds and electric fields as well as neutral temperature profiles. The instruments aboard the sounding rocket will observe full-disk solar EUV and FUV irradiance measurements in the 2 - 131 nm band along with a high speed multi-wavelength photometer package that will provide altitude profiles of thermospheric neutral species along the rocket track. The dayglow instrument will cover 60 - 140 nm spectral range and observe the emissions in a direction perpendicular to the rocket axis, which will point towards the Sun. With these measurements, we hope to answer how well the EUV and FUV dayglow measurements can be used to provide a self-consistent measure of the day time ionosphere-thermosphere space environment.