Remington Rohel

and 2 more

Super Dual Auroral Radar Network (SuperDARN) consists of more than 30 monostatic high-frequency (HF, 10-18~MHz) radars which utilise signals scattered from decameter-scale ionospheric irregularities for studying dynamic processes in the ionosphere. By combining line-of-sight velocity measurements of ionospheric scatter echoes from radars with overlapping fields of view, SuperDARN provides maps of ionospheric plasma drift velocity over mid and high latitudes. The conventional SuperDARN radars consecutively scan through sixteen beam directions with dwelling time of 3.5 s/beam, which places a lower limit of one minute to sample the entire field of view. In this work we remove this limitation by utilizing advanced capabilities of the recently developed Borealis digital SuperDARN radar system. Combining a wide transmission beam with multiple narrow reception beams allows us to sample all conventional beam directions simultaneously and to increase the sampling rate of the entire field of view by up to sixteen times without noticeable deterioration of the data quality. The wide-beam emission also enabled the implementation of multistatic operations, where ionospheric scatter signals from one radar are received by other radars with overlapping viewing areas. These novel operations required the development of a new model to determine the geographic location of the source of the multistatic radar echoes. Our preliminary studies showed that, in comparison with the conventional monostatic operations, the multistatic operations provide a significant increase in geographic coverage, in some cases nearly doubling it. The multistatic data also provide additional velocity vector components increasing the likelihood of reconstructing full plasma drift velocity vectors.

Daniel D Billett

and 4 more

Recent improvements to hardware for the Super Dual Auroral Radar Network systems operated by the University of Saskatchewan (named Borealis) have allowed for greater control of radar transmit and receive functionalities than previously possible. One of these functionalities is the application of a new operational mode, known as wide-beam imaging, which vastly improves the temporal resolution of the radars without compromising their spatial coverage. Wide-beam imaging allows for the retrieval of line-of-sight ionospheric drift velocities at a temporal resolution of 3.7\,s, a sixteen-fold improvement from the one-minute resolution offered by traditional operational modes. In this paper, we use wide-beam data from the Borealis SuperDARN systems, located in Canada, to derive local horizontal ionospheric plasma velocity fields above Northern Canada, Greenland, and the polar cap, at a 3.7\,s temporal resolution. For this local fitting of ionospheric velocity data, we use the Local Mapping of Ionospheric Electrodynamics (Lompe) spherical elementary current systems technique. This new data product, which we call the Fast Borealis Ionosphere (FBI), is compared to both the global SuperDARN spherical harmonic convection pattern data product (the Map Potential technique), as well as Lompe convection patterns derived using the traditional SuperDARN narrow-beam scanning mode. We show that Lompe systematically produces a better representation of the underlying radar velocity data than Map Potential, that the 3.7\,s wide-beam data contains a significant amount more ionospheric variability than narrow-beam, and that the high time-resolution convection patterns can resolve dynamic ionospheric events lasting on the order of tens of seconds.