API Reference / airmass · function
Function: airmass()
function airmass(altAppDeg): number;
Relative optical air mass at an apparent altitude (Kasten & Young 1989). 1.0 at the zenith, ~38 at the horizon; below the horizon the horizon value is returned (the path length stops growing once the ray grazes).
Parameters
| Parameter | Type |
|---|---|
altAppDeg | number |
Returns
number