Case study for ionospheric irregularity monitoring onboard the ARAON icebreaker research vessel

Ionosphere is the main error source for radio communication such as the Global Navigation Satellite System (GNSS). The ionospheric electrons delay the GNSS signals as well as the electron density irregularities degrade the GNSS signal intensity or cause the loss of signal lock. Consequently, the ionospheric error reduces the GNSS positioning performance, so ionospheric monitoring and correction of ionospheric effects are very important. Numerous GNSS receivers have been used to monitor the ionosphere as a very efficient instrument on the globe, but they have usually been operated on the ground or the satellite. In the oceanic area, it is hard to operate the GNSS receiver on the surface, and the satellite observations pass within only a few minutes. Hence, the absence of ionospheric observation in the ocean is inevitable, and it leads to a reduction of not only the ionospheric modeling precision on the global scale but also GNSS positioning performance in the ocean. In order to fill up the observation gap in the ocean, we conducted a special observation campaign operating the GNSS receiver on the icebreaker, ARAON, which is managed by Korea Polar Research Institute. The high-performed GNSS scintillation receiver, which can detect the GNSS signals in 50 Hz temporal resolution, was operated during 276 days of research voyage including both the Arctic and the Antarctic routes. The well-known daily variations of total electron contents (TEC) appeared, and TEC increased when the ARAON passed through the equatorial region. The ionospheric scintillation frequently occurred in the Arctic routes rather than the Antarctic routes. The positioning error based on GNSS signals increased in both polar routes. We also analyzed the motion sensor data of the ARAON and compared it with the ionospheric parameters. In this presentation, we show the campaign research results.