pvlib.atmosphere.get_relative_airmass#
- pvlib.atmosphere.get_relative_airmass(zenith, model='kastenyoung1989')[source]#
Calculate relative (not pressure-adjusted) airmass at sea level.
Parameter
model
allows selection of different airmass models.- Parameters:
zenith (numeric) – Zenith angle of the sun. [degrees]
model (string, default 'kastenyoung1989') –
Available models include the following:
’simple’ - secant(apparent zenith angle) - Note that this gives -Inf at zenith=90
’kasten1966’ - See [1] - requires apparent sun zenith
’youngirvine1967’ - See [2] - requires true sun zenith
’kastenyoung1989’ (default) - See [3] - requires apparent sun zenith
’gueymard1993’ - See [4], [5] - requires apparent sun zenith
’young1994’ - See [6] - requires true sun zenith
’pickering2002’ - See [7] - requires apparent sun zenith
’gueymard2003’ - See [8], [9] - requires apparent sun zenith
- Returns:
airmass_relative (numeric) – Relative airmass at sea level. Returns NaN values for any zenith angle greater than 90 degrees. [unitless]
Notes
Some models use apparent (refraction-adjusted) zenith angle while other models use true (not refraction-adjusted) zenith angle. Apparent zenith angles should be calculated at sea level.
Comparison among several models is reported in [10].
References
Examples using pvlib.atmosphere.get_relative_airmass
#

Modelling shading losses in modules with bypass diodes