Interface for a sPECtral Matrix ANalysis (iPECMAN) is an online data analysis tool aimed at multi-dimensional measurements of planetary electromagnetic fields. It calculates characteristics of electromagnetic waves from in-situ spacecraft measurements. These characteristics are the key signatures of fundamental process in the solar wind and planetary magnetospheres. The demonstrator is based on the PRASSADCO (PRopagation Analysis of STAFF-SA Data with COherency tests) analysis tool, developed originally in the frame of the ESA Cluster Project. PRASSADCO (link) is a tool designed to analyze multicomponent measurements of electromagnetic waves. It implements a number of methods used to estimate polarization and propagation parameters, such as
- the degree of polarization,
- sense of elliptic polarization and
- axes of polarization ellipse,
- the wave vector direction,
- the Poynting vector,
- the refractive index.
The above methods have been previously used and validated for analysis of data from the STAFF-SA instruments onboard the four Cluster spacecraft, the STAFF/DWP instrument onboard the Double Star TC-1 spacecraft, the LFEW instrument onboard the Double Star polar TC-2 spacecraft, the Cassini RPWS data, the IMSC and ICE instruments on the DEMETER spacecraft, the Polar PWI-HFWR data, and data from the EMFISIS Waves instrument onboard the NASA Van Allen Probes Spacecraft.
The iPECMAN implementation of this method interfaces with VESPA and allows to query and retrieve the source data in the form of spectral matrices through EPN-TAP interface. Internally, the web service uses a modular design which allows to easily add support for new source datasets in different formats.
Example of the PRASSADCO output as presented in Santolik et al., 2014 , Fine structure of large-amplitude chorus wave packets, Geophys. Res. Lett., 41, 293–299, doi:10.1002/2013GL058889. Analysis of one snapshot of magnetic field waveforms recorded by the EMFISIS Waves instrument onboard Van Allen Probe A on 14 November 2012. Frequency-time plots of (a) the sum of the power spectral densities of three orthogonal magnetic components, (b) the ellipticity of the magnetic field polarization with a sign corresponding to the sense of polarization, (c) the planarity of the magnetic field polarization, and (d) the angle between the wave vector and the background magnetic field.
Example of PRASSADCO output as presented in Santolik et al., 2011, Intense plasma wave emissions associated with Saturn’s moon Rhea, Geophys. Res. Lett., 38, L19204, doi:10.1029/2011GL049219 . (a, b) Sum of power‐spectral densities from the three orthogonal magnetic components of the WFR/RPWS instrument onboard Cassini; (c, d) Sum of power spectral densities from two electric components; (e, f) Angle between the wave vector direction and B0. (g, h) Ellipticity obtained as the ratio of the two largest axes of the magnetic‐field polarization ellipsoid with the sign reflecting the sense of polarization. (i, j) Component of the Poynting vector along B0 normalized by the estimated uncertainty of the analysis method.