The investigators will develop and deploy an all-sky imager for detecting proton aurora. The imager will provide wavelength resolution to determine the Doppler profile of the hydrogen auroral emissions produced by charge exchange of precipitating protons. The wavelength resolution will aid in separating the hydrogen emissions (proton aurora) from other auroral emissions, which can be very intense in comparison and have been troublesome in past hydrogen aurora measurements. The observation of the Doppler shift will also allow the inversion of the line of sight velocity distribution of the precipitating protons. The design of the instrument enables effective elimination of background emissions without losing the spatial information available from an all-sky camera field-of-view. The instrument will be constructed and tested in the laboratory in the first year of the project. Then it will be fielded at a high latitude auroral station, such as Poker Flat, Alaska. The distribution of proton aurora will be used to infer the dynamics of the closed field line region of the magnetosphere and its response to magnetospheric substorms and changes in the solar wind.
