wradlib Documentation - Bitbucket

wradlib Documentation, Release 0.1.1
References
[Jacobi2011]
3.12.4 wradlib.atten.correctAttenuationConstrained
wradlib.atten.correctAttenuationConstrained(gateset, a_max=0.000167, a_min=2.33e-05,
b_max=0.7, b_min=0.2, na=30, nb=5,
l=1.0, mode=’error’, constraints=None,
constr_args=None, diagnostics={})
Gate-by-Gate attenuation correction based on the iterative approach of Stefan Kraemer [Kraemer2008] with a
generalized and arbitrary number of constraints.
Parameters gateset : array
Multidimensional array, where 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_max : float
initial value for linear coefficient of the k-Z relation ( k = a ∗ Z b ). Per default set to
1.67e-4.
a_min : float
minimal allowed linear coefficient of the k-Z relation ( k = a ∗ Z b ) in the downwards
iteration of a in case of signal overflow (sum of signal and attenuation exceeds the
threshold thrs). Per default set to 2.33e-5.
b : float
exponent of the k-Z relation ( k = a ∗ Z b ). Per default set to 0.7.
n : integer
l : float
number of iterations from a_max to a_min. Per default set to 30.
length of a range gate [km]. Per default set to 1.0.
mode : string
Controls how the function reacts in case of signal overflow (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
Per default set to ‘zero’. Any other mode will raise an Exception.
constraints : list
list of constraint functions. The signature of these functions has to be constraint_function(gateset,
k, *‘constr_args‘). Their return value must be a boolean array
of shape gateset.shape[:-1] set to True for beams, which do not fulfill the constraint.
62 Chapter 3. Library Reference