astrorefraction: Astronomical refraction

In chepec/photoec: Solar spectra and constants for photoelectrochemistry

Astronomical refraction

Description

Calculate the astronomical refraction from zenith angle

Usage

astrorefraction(z = 48.2)

Arguments

z	zenith angle in degrees

Details

Calculate the astronomical refraction, R, based on Oriani's power series in terms of tan Z (where Z is the zenith angle) neglecting terms beyond third order and under the assumption that the height of the atmosphere is small compared to the radius of the Earth. This function works well up to around 70° of zenith angle, but will return non-physical values at higher angles. Astronomical refraction becomes complicated close to the horizon (for more on that, see quoted sources).

Value

refraction, in degrees You might want to convert this value back to arcseconds using degrees2asec

See Also

Mahan, A.I., 1962. Astronomical refraction–some history and theories. Appl. Opt., AO 1, 497–511. https://doi.org/10.1364/AO.1.000497

Woolard, E.W., Clemence, G.M., 1966. Spherical astronomy. Elsevier.

Auer, L.H., Standish, E.M., 2000. Astronomical refraction: computational method for all zenith angles. AJ 119, 2472. https://doi.org/10.1086/301325

chepec/photoec documentation built on July 27, 2023, 11:33 a.m.