Abstract
The ground-based, high-frequency radars of the Super Dual Auroral Radar
Network (SuperDARN) observe backscatter from ionospheric field-aligned
plasma irregularities and features on the Earth’s surface out to ranges
of several thousand kilometers via over-the-horizon propagation of
transmitted radio waves. Interferometric techniques can be applied to
the received signals at the primary and secondary antenna arrays to
measure the vertical angle of arrival, or elevation angle, for more
accurate geolocation of SuperDARN observations. Calibration of SuperDARN
interferometer measurements however remains challenging for several
reasons, including a 2$\pi$ ambiguity in the phase
correction factor needed to account for differences in the electrical
path lengths between signals received at the two antenna arrays. We
present a new technique using multi-frequency ionospheric and ground
backscatter observations for the calibration of SuperDARN interferometer
data, and demonstrate its application to both historical and recent
data.