obspy.signal.polarization.polarization_analysis

polarization_analysis(stream, win_len, win_frac, frqlow, frqhigh, stime, etime, verbose=False, method='pm', var_noise=0.0, adaptive=True)[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. Only used for method='vidale'.

  • frqhigh (float) – higher frequency. Only used for method='vidale'.

  • 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".

  • adaptive (bool) – switch for adaptive window estimation (defaults to True). If set to False, the window will be estimated as 3 * max(1/(fhigh-flow), 1/flow).

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.