A comparative study of ionospheric irregularity drift velocity using a GNSS receiver array and SuperDARN at high latitude

When comparing the SuperDARN High Frequency (HF) backscatter and GNSS receiver measurements during ionospheric scintillations, most of the previous studies are not direct point-to-point comparisons, as they often only utilize the HF backscatter data from a single SuperDARN beam covering the approximated SuperDARN-GNSS receiver line-of-sight (LOS) direction, which could not account for the piercing location of each individual satellite in the ionosphere. We have established a more adequate comparison algorithm by projecting each GNSS satellite's ionospheric penetration point (IPP) onto the SuperDARN's field-of-view, and then identify the specific SuperDARN grid to perform the comparison. In this paper. a quantitative comparison study is conducted using this algorithm on simultaneous measurements from the Kodiak SuperDARN and a GNSS receiver array at Gakona, Alaska. The objective is to look for the availability of the matching SuperDARN backscatter data when the GNSS receiver array records ionospheric scintillation events. In addition, using the matching data from the two instruments, we compare the SuperDARN's LOS ionospheric irregularity drift velocity measurements against the estimations produced by the time-frequency spaced-receiver algorithm we have developed.