Abstract
We built an integrated nonlinear analysis software -INA- designed to
study space plasma turbulence and intermittency. The MATLAB programming
environment was used for the algorithmic development and implementation
of methods for spectral analysis, multiscale fluctuations and
multifractal analysis. The performance of INA is demonstrated using
magnetic field measurements from the Cluster 3 spacecraft during an
inbound pass through the Earth’s magnetosheath region. We show how
specific features of the power spectral density (PSD) can be mapped to
localised time-frequency regions in the spectrogram representation, and
identify multiple intermittent events using the wavelet-based local
intermittency measure (LIM). Multiscale probability density functions
(PDFs) showed clear departures from Gaussianity, signifying the presence
of intermittency. Structure functions (SFs) and rank-ordered
multifractal analysis (ROMA) revealed the multifractal nature of the
analysed signal. INA is freely distributed as a standalone executable
file to any interested user, and provides an integrated, interactive,
and user-friendly environment in which one can import a dataset,
customize key analysis parameters, apply multiple methods on the same
signal and then export high-quality, publication-ready figures. These
are only a few of the many distinguishing features of INA.