wradlib Documentation - Bitbucket
wradlib Documentation - Bitbucket
wradlib Documentation - Bitbucket
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<strong>wradlib</strong> <strong>Documentation</strong>, Release 0.1.1<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 />
initial value for linear coefficient of the k-Z relation ( k = a ∗ Z b ). Per default set to<br />
1.67e-4.<br />
a_min : float<br />
minimal allowed linear coefficient of the k-Z relation ( k = a ∗ Z b ) in the downwards<br />
iteration of a in case of signal overflow (sum of signal and attenuation exceeds the<br />
threshold thrs). Per default set to 2.33e-5.<br />
b : float<br />
exponent of the k-Z relation ( k = a ∗ Z b ). Per default set to 0.7.<br />
n : integer<br />
l : float<br />
number of iterations from a_max to a_min. Per default set to 30.<br />
length of a range gate [km]. Per default set to 1.0.<br />
mode : string<br />
Controls how the function reacts in case of signal overflow (sum of signal and attenuation<br />
exceeds the threshold thrs). Possible values:<br />
‘warn’ : emit a warning through the module’s logger but continue execution<br />
‘zero’ : set offending gates to 0.0<br />
‘nan’ : set offending gates to nan<br />
Per default set to ‘zero’. Any other mode will raise an Exception.<br />
thrs_dBZ : float<br />
Threshold, for the attenuation corrected signal [dBZ], which is deemed unplausible. Per<br />
default set to 59.0 dBZ.<br />
max_PIA : float<br />
threshold, for the maximum path integrated attenuation [dB] which allows reasonable<br />
attenuation corrections. Per default set to 20.0 dB.<br />
Returns pia : array<br />
Array with the same shape as gateset containing the calculated attenuation [dB] for<br />
each range gate. In case the input array (gateset) contains NaNs the corresponding<br />
beams of the output array (k) will be set as NaN, too.<br />
Raises AttenuationOverflowError :<br />
Exception, if attenuation exceeds thrs even with smallest possible linear coefficient<br />
(a_min) and no handling mode is set.<br />
3.12. Attenuation Correction 61
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