LOCAL HOUR ANGLE OF ARIES TABLES

Frederick L. Devereux, Jr.

Peer Reviewed

Abstract: The first point of Aries (T) is the base reference point for measurement o celestial positions. Modern navigational practice requires that the singular measurement of Aries's position westward from the observer's celestial meridian be determined as an essential factor in the solution of many navigational problems. This angle is the local hour angle of Aries (LHA ã), which is usually derived from the Greenwich hour angle of Aries (GHA ã) obtained from an almanac. The traditional manual computation method of finding LHA ã involves conversion of zone time (ZT) to Greenwich mean time (GMT), inspection of two almanac pages to obtain GHA ã at GMT, and application of the observer's longitude to GHA ã in order to solve for LHA ã at the observer's meridian. The sexagesimal system of numbers is employed and many require as many as twelve entries.
Published in: NAVIGATION, Journal of the Institute of Navigation, Volume 18, Number 2
Pages: 253 - 258
Cite this article: Devereux, Frederick L., Jr.,, "LOCAL HOUR ANGLE OF ARIES TABLES", NAVIGATION, Journal of The Institute of Navigation, Vol. 18, No. 2, Summer 1971, pp. 253-258.
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