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Re: Lunars.
From: R.H. van Gent
Date: 2001 Jul 04, 3:26 PM
From: R.H. van Gent
Date: 2001 Jul 04, 3:26 PM
nigel_gardner wrote: > > Anyone out there with a good algorithm and process for longitude by lunars? You can find a good discussion of how to use observations of lunar distances (lunars) for determining longitude at sea in volume 1 of: W. Chauvenet, _A Manual of Spherical and Practical Astronomy: Embracing the General Problems of Spherical Astronomy, the Special Applications to Nautical Astronomy, and the Theory and Use of Fixed and Portable Astronomical Instruments_, 5th ed.(J.B. Lippincott Co., Philadelphia, 1900). Chauvenet explains the astronomical theory in detail, discusses the 'rigorous' and the 'approximative' method and gives a few worked out examples. There you will also find a detailed discussion of the various correction factors affecting seaman's instruments and the observations. There are probably more (and perhaps even better) 19th-century sources in which you can find the method of the lunars explained in detail, but Chauvenet should be relatively easy to find as it was reprinted several times and was even available in the 1960's as a Dover reprint. ======================================================== * Robert H. van Gent * Tel/Fax: 00-31-30-2720269 * * Zaagmolenkade 50 * * * 3515 AE Utrecht * E-mail: r.h.vangent@astro.uu.nl * * The Netherlands * * ******************************************************** * Home page: http://www.phys.uu.nl/~vgent/homepage.htm * ========================================================