Miscellaneous ADMIRALTY Astronomical Publications

Rapid Sight Reduction Tables for Navigation is available as a three-volume set.

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. This publication is aimed at the navigator using astro-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 0 to 40° north and south and declinations 0 to 29° degrees north and south. Volume 3 covers latitudes 39° to 89°degrees north and south and declinations 0 to 29° degrees north and south.

This is a joint publication with the United States Naval Observatory.

NavPac software enables navigators and astronomers to compute their position at sea. It provides methods for calculating the positions of the Sun, Moon, navigational planets and stars over several years to a consistent precision, with the aid of a pocket calculator, personal computer or laptop.

This publication is used by the Royal Navy and by many navigators who require an independent means of navigation.

A worldwide resource for fundamental astronomical data, the Astronomical Almanac includes contributions from astronomical experts, as well as a wide variety of technical and general astronomical information. This includes: 

• Positions of the Sun, Moon and planets to milli-arcsecond precision for each year
• Positions of dwarf planets, small solar system bodies planetary satellites for each year
• 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
• Reference data for stars and stellar systems and related astronomical constants and techniques

This is a joint publication with the United States Naval Observatory.

The Star Almanac contains positions of the Sun, Polaris and selected bright stars in a tabular format for easy identification. It is ideal for land surveyors who use astronomical observations to determine their geographical position or the direction to true north. This includes:

• A CD containing the almanac in PDF format and the coefficients representing the positions of the Sun and stars in ASCII files
• Coefficients for calculating the Greenwich hour angle and declination of all the stars published in The Star Almanac, accurate to about 1 arcsecond
• Polynomial coefficients for calculating R (GHA Aries - UT), declination, E and semi-diameter of the Sun are also included
• 695 stars in the selection used in NP321, including all stars brighter than the 4th magnitude

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 (GP100). This includes:

• Phases of the Moon, eclipses of the Sun and Moon
• Principal occultations, planetary phenomena, elongations and magnitudes of the planets, calendarial information, time zone map and short period comet data
• Times of sunrise/set and moonrise/set
• Tabulated equations of time, the declination of the Sun and the Greenwich hour angles of the pole stars Polaris and Sigma Octantis

This is a joint publication with the United States Naval Observatory.

To find out more information or to organise purchase, please contact your ADMIRALTY Distributor. If you don’t have a preferred distributor, you can search a list of worldwide, experienced and trusted distributors on our Find an ADMIRALTY Distributor page.