wradlib.atten.correct_attenuation_hb

wradlib.atten.correct_attenuation_hb(gateset, coefficients={'a': 0.000167, 'b': 0.7, 'gate_length': 1.0}, mode='except', thrs=59.0)

Gate-by-Gate attenuation correction according to [Hitschfeld et al., 1954]

Parameters
  • gateset (numpy.ndarray) – multidimensional array. The range gates (over which iteration has to be performed) are supposed to vary along the last dimension so, e.g., for a set of l radar images stored in polar form with m azimuths and n range-bins the input array’s shape can be either (l,m,n) or (m,l,n) data has to be provided in decibel representation of reflectivity [dBZ]

  • a (float) – proportionality factor of the k-Z relation (\(k=a \cdot Z^{b}\)). Per default set to 1.67e-4.

  • b (float) – exponent of the k-Z relation ( \(k=a \cdot Z^{b}\) ). Per default set to 0.7.

  • gate_length (float) – length of a range gate [km]. Per default set to 1.0.

  • mode (string) –

    controls how the function reacts, if the sum of signal and attenuation exceeds the threshold thrs Possible values:

    • ’warn’ : emit a warning through the module’s logger but continue execution

    • ’zero’ : set offending gates to 0.0

    • ’nan’ : set offending gates to nan

    • ’except’: raise an AttenuationOverflowError exception

    Any other mode will also raise the Exception.

  • thrs (float) – threshold, for the sum of attenuation and signal, which is considered implausible.

Returns

pia (numpy.ndarray) -- Array with the same shape as ``gateset` containing the calculated attenuation [dB] for each range gate.

Raises

AttenuationOverflowError – Exception, if attenuation exceeds thrs and no handling mode is set.

Examples

See Hitschfeld and Bordan.