Advanced regression models for ionospheric delay prediction using GNSS
measurements
Abstract
Achieving high accuracy for Global Navigation Satellite Systems (GNSS)
positioning at low cost, is the main reason for the wide acceptance that
has received the technique of Precise Point Positioning (PPP) from the
geodetic community. However, the long convergence time required to
achieve centimeter-level accuracy in positioning, remains of PPP’s main
disadvantage. Our proposed method is aiming to provide accurate
prediction of ionosphere variations at regional level, in a form
suitable to be applied in PPP processing as external ionospheric
information, so that to successfully deal with the ionospheric error
effects. Machine Learning regression-based approaches for sequence
modeling are suitable for predicting the ionospheric variability.
Gaussian Process Regression (GPR) and Support Vector Regression (SVR)
are introduced for ionospheric variations modeling at different
locations of the International GNSS Service (IGS) network. The proposed
algorithms predict the future electronic content per satellite from a
specific station, fitting a non-linear model. The evaluation of our
proposed methods for vertical total electron content (VTEC) values
prediction is compared against the traditional Autoregressive (AR) and
Autoregressive Moving Average (ARMA) methods, per satellite. Additional,
mean TEC timeseries are compared against classical Global Ionospheric
Maps (GIM), NeQuick and International Reference Ionosphere (IRI) models.