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wradlib Documentation - Bitbucket

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<strong>wradlib</strong> <strong>Documentation</strong>, Release 0.1.1<br />

Parameters gateset : array<br />

multidimensional array. The range gates (over which iteration has to be performed) are<br />

supposed to vary along the last dimension so, e.g., for a set of l radar images stored<br />

in polar form with m azimuths and n range-bins the input array’s shape can be either<br />

(l,m,n) or (m,l,n) data has to be provided in decibel representation of reflectivity [dBZ]<br />

a : float<br />

b : float<br />

l : float<br />

proportionality factor of the k-Z relation ( k = a ∗ Z b ). Per default set to 1.67e-4.<br />

exponent of the k-Z relation ( k = a ∗ Z b ). Per default set to 0.7.<br />

length of a range gate [km]. Per default set to 1.0.<br />

mode : string<br />

controls how the function reacts, if the sum of signal and attenuation exceeds the threshold<br />

thrs Possible values: ‘warn’ : emit a warning through the module’s logger but<br />

continue execution ‘zero’ : set offending gates to 0.0 ‘nan’ : set offending gates to nan<br />

Any other mode and default setting will raise an Exception.<br />

thrs : float<br />

threshold, for the sum of attenuation and signal, which is deemed unplausible.<br />

Returns pia : array<br />

Array with the same shape as gateset containing the calculated attenuation [dB] for<br />

each range gate.<br />

Raises AttenuationOverflowError :<br />

Exception, if attenuation exceeds thrs and no handling mode is set.<br />

References<br />

[Hitschfeld1954]<br />

3.12.2 <strong>wradlib</strong>.atten.correctAttenuationKraemer<br />

<strong>wradlib</strong>.atten.correctAttenuationKraemer(gateset, a_max=0.000167, a_min=2.33e-<br />

05, b=0.7, n=30, l=1.0, mode=’zero’,<br />

thrs_dBZ=59.0)<br />

Gate-by-Gate attenuation correction according to Stefan Kraemer [Kraemer2008].<br />

Parameters gateset : array<br />

Multidimensional array, where the range gates (over which iteration has to be performed)<br />

are supposed to vary along the last dimension so, e.g., for a set of l radar<br />

images stored in polar form with m azimuths and n range-bins the input array’s shape<br />

can be either (l,m,n) or (m,l,n).<br />

Data has to be provided in decibel representation of reflectivity [dBZ].<br />

a_max : float<br />

3.12. Attenuation Correction 59

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