Analysis of geomagnetic pulsations using multiwavelets spectral and polarization method

In this paper, we present an algorithm based on the multi-wavelet transform and on the multitaper spectral and polarization methods to estimate polarization parameters of a non-stationary geomagnetic pulsations signals. Through the first right-singular vector and the singular values, obtained from singular value decomposition (SVD) of the multiwavelet eigenspectra matrix M(f,t) of the three-component geomagnetic pulsations we determined the polarization parameters of the hydromagnetic waves in the time–frequency plane. It was used in the multiwavelet polarization analysis to estimate the polarization parameters of geomagnetic pulsations signals obtained from a large geomagnetic storm on March 24, 1991. The results showed that this method is a powerful tool to find events with high degree of polarization and allow to determine the polarization parameters continually in both time and frequency, giving an appropriate resolution to study pulsations that have narrow spectral band and short-lived components.