pyart.correct.attenuation.calculate_attenuation

pyart.correct.attenuation.calculate_attenuation(radar, z_offset, debug=False, doc=15, fzl=4000.0, rhv_min=0.8, ncp_min=0.5, a_coef=0.06, beta=0.8, refl_field=None, ncp_field=None, rhv_field=None, phidp_field=None, spec_at_field=None, corr_refl_field=None)

Calculate the attenuation from a polarimetric radar using Z-PHI method.

Parameters :

radar : Radar

Radar object to use for attenuation calculations. Must have copol_coeff, norm_coherent_power, proc_dp_phase_shift, reflectivity_horizontal fields.

z_offset : float

Horizontal reflectivity offset in dBZ.

debug : bool

True to print debugging information, False supressed this printing.

Returns :

spec_at : dict

Field dictionary containing the specific attenuation.

cor_z : dict

Field dictionary containing the corrected reflectivity.

Other Parameters:  

doc : float

Number of gates at the end of each ray to to remove from the calculation.

fzl : float

Freezing layer, gates above this point are not included in the correction.

rhv_min : float

Minimum copol_coeff value to consider valid.

ncp_min : float

Minimum norm_coherent_power to consider valid.

a_coef : float

A coefficient in attenuation calculation.

beta : float

Beta parameter in attenuation calculation.

refl_field, ncp_field, rhv_field, phidp_field : str

Field names within the radar object which represent the horizonal reflectivity, normal coherent power, the copolar coefficient, and the differential phase shift. A value of None for any of these parameters will use the default field name as defined in the Py-ART configuration file.

spec_at_field, corr_refl_field : str

Names of the specific attenuation and the corrected reflectivity fields that will be used to fill in the metadata for the returned fields. A value of None for any of these parameters will use the default field names as defined in the Py-ART configuration file.

References

Gu et al. Polarimetric Attenuation Correction in Heavy Rain at C Band, JAMC, 2011, 50, 39-58.