pyart.filters.moment_and_texture_based_gate_filter

pyart.filters.moment_and_texture_based_gate_filter(radar, zdr_field=None, rhv_field=None, phi_field=None, refl_field=None, textzdr_field=None, textrhv_field=None, textphi_field=None, textrefl_field=None, wind_size=7, max_textphi=20.0, max_textrhv=0.3, max_textzdr=2.85, max_textrefl=8.0, min_rhv=0.6)[source]

Create a filter which removes undesired gates based on texture of moments.

Creates a gate filter in which the following gates are excluded:

  • Gates where the instrument is transitioning between sweeps.

  • Gates where RhoHV is below min_rhv

  • Gates where the PhiDP texture is above max_textphi.

  • Gates where the RhoHV texture is above max_textrhv.

  • Gates where the ZDR texture is above max_textzdr

  • Gates where the reflectivity texture is above max_textrefl

  • If any of the thresholds is not set or the field (RhoHV, ZDR, PhiDP, reflectivity) do not exist in the radar the filter is not applied.

Parameters

  • radar (Radar) – Radar object from which the gate filter will be built.

  • zdr_field, rhv_field, phi_field, refl_field (str) – Names of the radar fields which contain the differential reflectivity, cross correlation ratio, differential phase and reflectivity from which the textures will be computed. A value of None for any of these parameters will use the default field name as defined in the Py-ART configuration file.

  • textzdr_field, textrhv_field, textphi_field, textrefl_field (str) – Names of the radar fields given to the texture of the differential reflectivity, texture of the cross correlation ratio, texture of differential phase and texture of reflectivity. A value of None for any of these parameters will use the default field name as defined in the Py-ART configuration file.

  • wind_size (int) – Size of the moving window used to compute the ray texture.

  • max_textphi, max_textrhv, max_textzdr, max_textrefl (float) – Maximum value for the texture of the differential phase, texture of RhoHV, texture of Zdr and texture of reflectivity. Gates in these fields above these limits as well as gates which are masked or contain invalid values will be excluded and not used in calculation which use the filter. A value of None will disable filtering based upon the given field including removing masked or gates with an invalid value. To disable the thresholding but retain the masked and invalid filter set the parameter to a value above the highest value in the field.

  • min_rhv (float) – Minimum value for the RhoHV. Gates below this limits as well as gates which are masked or contain invalid values will be excluded and not used in calculation which use the filter. A value of None will disable filtering based upon the given field including removing masked or gates with an invalid value. To disable the thresholding but retain the masked and invalid filter set the parameter to a value below the lowest value in the field.

Returns

gatefilter (GateFilter) – A gate filter based upon the described criteria. This can be used as a gatefilter parameter to various functions in pyart.correct.