An instance of class
AltAz represents a
location in the sky relative to the observer's horizon.
See Section 3.2, “Altazimuth coordinates”.
The constructor call has this form:
The altitude above the horizon in radians.
The azimuth angle in radians, where 0.0 is north, π/2 is east, and so on.
Instances have these attributes:
The altitude, normalized to [-π, π].
The azimuth, normalized to [0,2π).