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wradlib Documentation - Bitbucket

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

Notes<br />

The shape of elevations and ranges may differ in which case numpy’s broadcasting rules will apply and the<br />

shape of output will be that of the broadcast arrays. See the numpy documentation on how broadcasting works.<br />

References<br />

[Doviak1993]<br />

3.7.3 <strong>wradlib</strong>.qual.pulse_volume<br />

<strong>wradlib</strong>.qual.pulse_volume(ranges, h, theta)<br />

Calculates the sampling volume of the radar beam per bin depending on range and aperture.<br />

We assume a cone frustum which has the volume V=(pi/3)*h*(R**2 + R*r + r**2). R and r are the radii<br />

of the two frustum surface circles. Assuming that the pulse width is small compared to the range, we get<br />

R=r=tan(theta*pi/180)*range. Thus, the pulse volume simpy becomes a the volume of a cylinder with V=pi * h<br />

* range**2 * tan(theta*pi/180)**2<br />

Parameters ranges : array<br />

h : float<br />

the distances of each bin from the radar [m]<br />

pulse width (which corresponds to the range resolution [m])<br />

theta : float<br />

the aperture angle (beam width) of the radar beam [degree]<br />

Returns output : volume of radar bins at each range in ranges [m**3]<br />

3.8 Composition<br />

Combine data from different radar locations on one common set of locations<br />

extract_circle<br />

togrid<br />

compose_ko<br />

compose_weighted<br />

Extract the indices of coords which fall within a circle<br />

Interpolate data from a radar location to the composite grid or set of locations<br />

Composes grids according to quality information using quality information as a knockout criterion.<br />

Composes grids according to quality information using a weighted averaging approach.<br />

3.8.1 <strong>wradlib</strong>.comp.extract_circle<br />

<strong>wradlib</strong>.comp.extract_circle(center, radius, coords)<br />

Extract the indices of coords which fall within a circle defined by center and radius<br />

Parameters center : float<br />

radius : float<br />

coords : array of float with shape (numpoints,2)<br />

Returns output : 1-darray of integers<br />

3.8. Composition 53

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