The Nautical Almanac

The Nautical Almanac ( Nautical almanac and astronomical ephemeris ) is an astronomical yearbook of about 300 pages, which is designed specifically to sea for the rapid celestial navigation. The first almanac of the British Royal Greenwich Observatory was published in 1767 and was the first available means to determine the ship's longitude measured from lunar distances. Soon also tables for Sun and planets were taken.

The Almanac is published a year in advance and includes hourly ephemeris for the sun, moon and the five bright planets, today's apparent star positions of 57 navigational stars and details of the dawn. It is designed to have an accuracy of 0.1 ' ( arc minutes ), which is sufficient for the nautical and eliminates tedious interpolations of the table values. Also, the time correction DUT1 can be omitted, because the coordinates for a predicted Earth's rotation (UT1 ) apply.

Until the mid-20th century, the almanac was a more comprehensive yearbook, which many states and institutions gave out on their own (eg, Heidelberg and Berlin Astronomical Yearbook ). As this multi- redundant labor has been replaced by international cooperation, remained the " fast track " at the Nautical Almanac, while a majority of more precise forecasts of the Heidelberg Institute went (see Astronomical Computing Institute and FK5 ).

The Nautical Almanac is published in two identical editions for the United Kingdom and the United States ( HM Nautical Almanac Offices, London Secretary of State, and United States Naval Observatory, Washington), as well as licensed editions for around ten other languages ​​.

  • ISBN 0-11-887322-9, ISSN 0077- 619x
Minute of arc Berliner Astronomisches Jahrbuch Astronomical Calculation Institute (University of Heidelberg) Position line George William Hill Simon Newcomb
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