NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Lunar distances
From: George Huxtable
Date: 2002 Jan 25, 8:26 AM
From: George Huxtable
Date: 2002 Jan 25, 8:26 AM
Dan Allen said- >I am, however, still waiting for George Huxtable's summary of lunars. >I still do not have those clear in my mind either! > >Dan ============================ Reply, from George.- Dan is quite right to remind me that I have not yet fulfilled my promise. But I haven't forgotten it, and have been working on putting the thing together. It will be a few days yet. Let me explain the problem that I'm having. My intention at first was simply to supply a few relevant equations. But then the context for those equations needed explaining. Which brought up other matters that needed explaining. And so on. The whole thing starts to grow, if it's going to be intelligible to someone who isn't yet at all familiar with lunars. There's no escaping the fact that lunar distaces are a complex business. If there existed accessible textbooks on the subject, I could have simply referred the reader to those. The only modern one I am familiar with is C.H.Cotter, "A History of Nautical Astronomy" (London, 1968), which is very hard to find. If any reader knows of other useful textbooks on lunars, please say. Eric Haberfellner tells me of "Self-Contained Celestial Navigation with H.O. 208" by John S. Letcher, Jr., published by International Marine Publishing Company in 1977. He says- "This book (to my suprise) has a chapter on "Time by Lunar Distance" and a chapter on "Time by Lunar Lines of Position". This would make it one of the few "modern" books that deals with this subject." I am also informed by Eric of Bruce Stark's "Tables for Clearing the Lunar Distance and Finding G.M.T. by Sextant Observation", and would be interested to hear listmembers' opinions about this book. However I have had to work on the basis of writing for members who have access to none of those works, and are new to lunars, but are familiar with the basics of ordinary astronavigation and the measurement of altitude by sextant. Would that pitch it about right? More soon. George Huxtable. ------------------------------ george@huxtable.u-net.com George Huxtable, 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. Tel. 01865 820222 or (int.) +44 1865 820222. ------------------------------
