Calculates the height of a radar bin taking the refractivity of the atmosphere into account.

Based on the bin altitude is calculated as

$h = \sqrt{r^2 + (k_e r_e)^2 + 2 r k_e r_e \sin\theta} - k_e r_e$
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

• sitealt (float) – Altitude in [m] a.s.l. of the referencing radar site

• 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

altitude (numpy.ndarray) – Array of heights of the radar bins in [m]