On High-latitude GPS Scintillations: Plasma Flows and Operational Effect

Answering the questions of the causes of ionospheric scintillation and its effects on Global Positioning System (GPS) functionality at high latitudes becomes increasingly essential with rising global temperatures and decreased sea ice extent in the Arctic Ocean. To increase modern understanding of ionospheric storms and the affect of increased solar activity on the precision of satellite-based navigation tools two distinct but interdependent analyses were performed. First, a novel Poker Flat Incoherent Scatter Radar (PFISR) mode and supporting all sky imagery data were used to detect the apparent motion of high-latitude ionospheric plasma leading to GPS scintillations. Located at Poker Flat Research Range near Fairbanks, Alaska, PFISR detects plasma densities along the line of sight of conjunctive GPS signals in the E and F regions of the ionosphere through a novel mode using five independent radar beams. All Sky imagery detects narrow band electron precipitation in a wide field of view. Cross-correlation methods in this study compare electron densities reported along each of five PFISR beams to detect when and where plasma structure patterns reoccur. The PFISR statistical analysis is then compared to apparent auroral motion captured by 557.7 nm all sky imagery. The three-dimensional characterization of apparent auroral motion captured by PFISR is within an order of magnitude of the two-dimensional apparent auroral motion captured by all sky imagery. Initial results indicate that this analysis technique can successfully be applied across data spanning four Arctic winters, with the potential to quantify the three-dimensional auroral motion within the ionosphere and enhance the utility of ISRs in detecting GPS scintillation. Second, a methodology is under development for conducting correlative analyses on scintillation data gathered from high-resolution Connected Autonomous Space Environment Sensor (CASES) GPS receivers. To isolate the effects of scintillation, we sought to remove the effects of other precision-harming processes such as errors due to satellite configuration like geometric dilution of precision (GDOP). Multiple correlative models were run to identify where meaningful relationships do and do not exist. In comparing the position solution accuracy between CASES and Continuously Operating Reference Stations (CORS) GPS receivers, we expect to see CORS receivers exhibiting greater magnitudes of error. We also expect that controlling for GDOP will reveal a meaningful relationship between scintillation and magnitude of error.