Question 1774Navigation General

The correct answer is C) Greenwich hour angle. The Greenwich hour angle (GHA) is the angle between the meridian of the observer's position and the meridian passing through the body (e.g., a celestial object such as the sun). This angle, combined with the body's declination, is used to determine the geographic position (GP) of the body for a high-altitude sight in a celestial navigation calculation. The other options are incorrect because observed altitude (A) is not used to determine the GP, and right ascension (B) and sidereal hour angle (D) are not the appropriate angle measurements for this calculation.