wradlib.georef.misc.site_distance#

wradlib.georef.misc.site_distance(r, theta, binalt, *, re=6371000, ke=1.3333333333333333)[source]#
wradlib.georef.misc.site_distance(obj: DataArray, **kwargs)
wradlib.georef.misc.site_distance(obj: Dataset, **kwargs)

Calculates great circle distance from bin at certain altitude to the radar site over spherical earth, taking the refractivity of the atmosphere into account.

Based on [Doviak et al., 1993] the site distance may be calculated as

\[s = k_e r_e \arcsin\left( \frac{r \cos\theta}{k_e r_e + h_n(r, \theta, r_e, k_e)}\right)\]

where \(h_n\) would be provided by bin_altitude.

Parameters
  • r (numpy.ndarray) – Array of ranges [m]

  • theta (scalar or numpy.ndarray) – Array broadcastable to the shape of r elevation angles in degrees with 0° at horizontal and +90° pointing vertically upwards from the radar

  • binalt (numpy.ndarray) – site altitude [m] amsl. same shape as r.

  • re (float, optional) – earth’s radius [m], defaults to 6371000.

  • ke (float, optional) – adjustment factor to account for the refractivity gradient that affects radar beam propagation. In principle this is wavelength- dependend. The default of 4/3 is a good approximation for most weather radar wavelengths

Returns

distance (numpy.ndarray) – Array of great circle arc distances [m]