Polar Cap Patches and the Influence on GPS Accuracy

As part of a course in Radar Diagnostics of Space Plasma. 4 hours of experiment time at the EISCAT Svalbard Radar (ESR) was allowed for each group of student. My group studied Polar Cap Patches’ influence on GPS Accuracy. The 42 m dish of the ESR was pointed along the magnetic field lines and the 32 m movable antenna was pointed towards the magnetic north with an azimuth -30 degrees and a low elevation. In addition to this, external data from the Kjell Hendriksen Observatory (KHO) GPS analysis was used. The instrument used for GPS data was NovAtel GPStation-6 receiver and GPS-703-GGG antenna with multi-constellation capability (GPS, GLONASS and GALILEO). The receiver has 120 channels, and for each visible spacecraft in the sky the scintillation indices (S4 and SigmaPhi) is calculated at 50 Hz resolution and every 60 s.

Although several prominent Polar Cap Patches were observed during the experiment, no correlation to the GPS data could be observed. The non-favourable orbitals for the GPS satellites in high latitudes are more likely to be a cause of accuracy problems with the GPS.

GPS data from KHO