The United Kingdom Hydrographic Office

Her Majesty's Nautical Almanac Office

The Nautical Almanac contains tabulations of the Sun, Moon navigational planets and stars for use in the determination of position at sea from sextant observations. In addition, it gives times of sunrise, sunset, twilights, moonrise and moonset, phases of the Moon and eclipses of the Sun and Moon for use in the planning of observations. All the necessary interpolation and altitude correction tables are provided as well as pole star tables and diagrams and notes for the identification of stars and planets. Information on standard times for most countries around the world is provided. A concise set of sight reduction tables and sight reduction form are also included.

This web page describe the publications produced by the UKHO in conjunction with HM Nautical Almanac Office.

The Office produces astronomical data suitable for a wide range of users, including professional and amateur astronomers, mariners, aviators, surveyors, the Armed Forces, the Police, lawyers, religious groups, architects, schools, diary and calendar manufacturers, photographers and film crews. In fact, anyone requiring astronomical information may require our services.

HMNAO is jointly responsible for producing the annual volumes of The Astronomical Almanac, The Nautical Almanac and Astronomical Phenomena in collaboration with our colleagues at the US Nautical Almanac Office within the Astronomical Applications Department of the US Naval Observatory. HMNAO also produces The Star Almanac, NavPac and Compact Data, The UK Air Almanac, Rapid Sight Reduction Tables for Navigation and Planetary and Lunar Coordinates in the United Kingdom.

The Nautical Almanac – NP314

The Nautical Almanac contains tabulations of the Sun, Moon navigational planets and stars for use in the determination of position at sea from sextant observations. In addition, it gives times of sunrise, sunset, twilights, moonrise and moonset, phases of the Moon and eclipses of the Sun and Moon for use in the planning of observations. All the necessary interpolation and altitude correction tables are provided as well as pole star tables and diagrams and notes for the identification of stars and planets. Information on standard times for most countries around the world is provided. A concise set of sight reduction tables and sight reduction form are also included.

Sight Reduction Tables for Marine Navigation – NP303 (AP3270)

Three volumes which can be used with The Nautical Almanac and designed to permit rapid position fixing by celestial means.

Volume 1 contains the altitude to 1' and true azimuth to 1° for the seven stars most suitable for finding your position with a sextant, for the complete range of latitudes and hour angles of Aries. The latest edition is that for epoch 2015·0, published in 2012. This publication is aimed at the navigator using celestial-navigation and provides the optimum selection of stars for a three-star fix.

Volume 2 and Volume 3 contain values of the altitude to 1' and azimuth to 1° for integral degrees of declination from 29° north to 29° south, for the complete range of latitudes and for all hour angles at which the zenith distance is less than 95° (97° between latitudes 70° and the poles) providing for sights of the Sun, Moon and planets. Volume 2 covers latitudes between 0° and 40°. Volume 3 covers latitudes between 39° and 89°.

NavPac and Compact Data – DP330

NavPac runs on a PC under Microsoft Windows providing the navigator with a simple and efficient method of calculating his position at sea using sextant observations. It also provides rise/set times and positions of the Sun, Moon, planets and navigations stars for planning astronomical sights. NavPac can also calculate great circle and rhumb line tracks.

The Astronomical Almanac – GP100

The Astronomical Almanac contains a wide variety of both technical and general astronomical information. The book is a worldwide resource for fundamental astronomical data and the flagship publication of the Nautical Almanac Office at the US Naval Observatory and Her Majesty's Nautical Almanac Office at the UKHO including contributions from astronomical experts worldwide. It contains positions of the Sun, Moon and planets to milli-arcsecond precision, positions of minor planets and planetary satellites for each year together with data relating to Earth orientation, time-scales and coordinate systems. Phenomena including eclipses of the Sun and Moon, sunrise/set, moonrise/set and twilight times are provided as well as fundamental astronomical reference data for stars and stellar systems, observatories and related astronomical constants and techniques.

A joint publication with the United States Naval Observatory.

• The 2013 and 2014 editions are available

The Star Almanac - NP321

This almanac contains positions of the Sun, Polaris and selected bright stars in a form which is convenient for land surveyors who use astronomical observations to determine their geographical position or direction to true north. This edition includes a CD-RoM which contains the almanac in pdf format and the coefficients representing the positions of the Sun and stars in ASCII files. ASCII data files are available on the CD-ROM which contain coefficients for calculating the Greenwich hour angle and declination of all the stars published in The Star Almanac, accurate to about 1 arcsecond. The polynomial coefficients for calculating R (GHA Aries - UT), declination, E and semi-diameter of the Sun are also included.

• The 2013 and 2014 editions are available
  

Astronomical Phenomena – GP200

This publication provides a summary of astronomical events.  It is published several years in advance and contains much of Section A of the corresponding Astronomical Almanac.  This publication includes phases of the Moon, eclipses of the Sun and Moon, principal occulations, planetary phenomena, elongations and magnitudes of the planets, times of sunrise/set, moonrise/set.  Also tabulated are the equation of time, the declination of the Sun and the Greenwich hour angles of the pole stars Polaris and Sigma Octantis.

• The 2013, 2014 and 2015 editions are available

How to Buy

Our Navigation Publications are available through all UKHO Admiralty Paper Distributors for which a link is given below. Our Astronomical Publications, namely, The Astronomical Almanac, Astronomical Phenomena and The Star Almanac for Land Surveyors are most easily obtained from the link given below. Planetary and Lunar Coordinates is available from the TSO Online Bookshop.

• Navigational Publications – UK Admiralty Distributors
• Astronomical Publications – UKHO Distributors: Thomas Gunn Online Shop
• If you have difficulty in finding any of our publications please contact UKHO Customer Services:

  Telephone:	+44 (0) 1823 723366
  Fax:	+44 (0) 1823 330561
  e-mail:	customerservices@ukho.gov.uk