Bright Limb Angle

Bright Limb Angle

Algorithms

Calculates the positional angle of the moon's bright limb

function MoonBrightLimbPositionAngle(date: TDateTime):extended;

function MoonBrightLimbPositionAngleZenith(date: TDateTime; latitude, longitude: extended):extended;

Description

The bright limb of the moon changes its orientation, either measured towards the north direction or towards the zenith at a given geographic position, as shown in the illustration. The zenith angle describes the apparent rotation of the moon; and it is not defined for the moon being exactly in zenith (or nadir).

Reference

These functions are based upon chapter 48 (46) of "Astronomical Algorithms".