obspy.signal.polarization.polarization_analysis

polarization_analysis(stream, win_len, win_frac, frqlow, frqhigh, stime, etime, verbose=False, method='pm', var_noise=0.0)[source]

Method carrying out polarization analysis with the [Flinn1965b], [Jurkevics1988], ParticleMotion, or [Vidale1986] algorithm.

Parameters:
  • stream (Stream) – 3 component input data.
  • win_len (float) – Sliding window length in seconds.
  • win_frac (float) – Fraction of sliding window to use for step.
  • var_noise (float) – resembles a sphere of noise in PM where the 3C is excluded
  • frqlow (float) – lower frequency for PM
  • frqhigh (float) – higher frequency for PM
  • stime (obspy.core.utcdatetime.UTCDateTime) – Start time of interest
  • etime (obspy.core.utcdatetime.UTCDateTime) – End time of interest
  • method (str) – the method to use. one of "pm", "flinn" or "vidale".
Return type:

dict

Returns:

Dictionary with keys "timestamp" (POSIX timestamp, can be used to initialize UTCDateTime objects), "azimuth", "incidence" (incidence angle) and additional keys depending on used method: "azimuth_error" and "incidence_error" (for method "pm"), "rectilinearity" and "planarity" (for methods "flinn" and "vidale") and "ellipticity" (for method "flinn"). Under each key a ndarray is stored, giving the respective values corresponding to the "timestamp" ndarray.