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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: HO 211 and Calculator Almanacs
From: Bill Murdoch
Date: 1999 Sep 08, 7:00 PM
From: Bill Murdoch
Date: 1999 Sep 08, 7:00 PM
Still another source of planetary, solar, and lunar data (and a lot more) is Montenbruck and Pfleger, Astronomy on the Personal Computer, Springer Verlag, 1994. The book contains programs in Pascal which are helpful guides for writing in any other language. The formulas used for the planets are (or seem to be) Newcombe's and for the moon are Brown's. He uses a neat trick with with the sine and cosine addition formulas to greatly minimize the number of calls to sin or cos which greatly speeds up the calculation of planetary pertubation terms. Also helpful is the Astronomical Almanac and The Explanatory Supplement to the Astronomical Almanac. Bill Murdoch