Regional spatio - temporal modeling of the ionospheric Vertical Total Electron Content (VTEC) using Multivariate Adaptive Regression B‒Splines (BMARS)

Abstract

Spatio‒temporal Regional modeling of the ionosphere in terms of the vertical total electron content (VTEC) is accomplished using a non‒parametric Multivariate Adaptive Regression B‒ Spline (BMARS) algorithm on the basis of Global Positioning System (GPS) observations. The basis functions are constructed as compactly supported tensor products of quadratic B‒Splines which are derived from the observations automatically. A smooth approximation is achieved by scale‒by‒scale model building strategy which searches for best fitting B Spline to the data at each scale. The real data set processed is gathered from ground based GPS stations in Europe and falls within the time interval of the geomagnetic storm on 15 February, 2011. The result of BMARS modeling apparently demonstrates the efficiency and the potential of the method. It is also compared both numerically and visually with a well‒known global and regional VTEC modeling based on spherical harmonics and B‒Splines respectively.