Spaced-GNSS receiver techniques for ionospheric irregularity drift velocity and height estimation based on high-latitude GNSS scintillation

Abstract

Spaced-GNSS receiver measurements offer an inexpensive approach for remote-sensing the ionospheric irregularity drift velocity during ionospheric scintillations. Conventional approaches targeting equatorial amplitude scintillations are less applicable in high latitude regions where phase scintillations are more prominent. This dissertation demonstrates spaced-receiver techniques that use multi-GNSS carrier phase measurements to estimate irregularity drift velocity and effective irregularity height at high latitudes during scintillations. A time-domain method and a time-frequency domain method are implemented to extract time lag information between receiver pairs when observing the same irregularity structure. Based on the front velocity model and the anisotropy model, a hybrid correlation model is developed to account for the topology of the irregularity. From the time lag information, the hybrid correlation model and known satellite-receiver geometry, the irregularity drift velocity can be obtained. In addition, an inversion technique for estimating the effective height of the irregularity is developed based on the anisotropy model. These techniques are applied to data collected by two GNSS receiver-arrays at Gakona and the Poker Flat Research Range in Alaska. The GNSS-estimated drift velocities at Poker Flat are in general agreement with measurements from the co-located incoherent scatter radar and the All-sky Imager. The effective height estimates also compared favorably against the incoherent scatter radar measurements.