wradlib.georef.misc.site_distance¶
- wradlib.georef.misc.site_distance(r, theta, binalt, re=None, ke=1.3333333333333333)¶
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 radarbinalt (
numpy.ndarray
) – site altitude [m] amsl. same shape as r.re (
float
) – earth’s radius [m]ke (
float
) – adjustment factor to account for the refractivity gradient that affects radar beam propagation. In principle this is wavelength- dependent. 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]