As seen from above the Earth's north pole, a star's local hour angle (LHA) for an observer near New York (red dot). Also depicted are the star's right ascension and Greenwich hour angle (GHA), the ...
By measuring the angle of the celestial body in the sky, the observer can get the local hour angle (LHA) of X, which is the angle subtended at P between Z and X (the angle between the Z and X's ...