NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Latitude by Lunar Distance
From: George Huxtable
Date: 2006 Nov 11, 16:25 -0000
From: George Huxtable
Date: 2006 Nov 11, 16:25 -0000
Frank Reed wrote- ...did YOU ever realize that you could determine a true | position fix using lunar distances without any horizon at all? I think it's | quite a novel concept for this group of people. Yes, I agree, it was an interesting notion, well worth bringing to our attention. A notion which is NOT devalued by the fact that it was first thought of nearly a century before; a fact which was also worth bringing to our attention. Whether that notion was practical or useful, then or now, is another matter. It was somewhat tarnished by Frank's rather extravagant claims made about its precision "to six miles". But Frank is being over-sensitive when he writes- I suppose that's why a couple of | people were determined to attack it instead of trying it out. I recognise myself as one of those couple, and wonder what Frank expects to get when he presents such a notion to our list. What he will get will be scrutiny, if this list is doing its job. Any such proposal will be unpicked and examined for holes and flaws. If it passes that test without serious defects coming to light, it's an indication (but nothing more than that) that perhaps the idea is indeed valid. This list acts an an almost-instant peer review, for which I have been truly grateful when it has found flaws in my own arguments; a more frequent occurrence than I wish to recall. We are not a mutual admiration society, and thank goodness for that. Finally, Frank has been asked to explain a procedure for deducing observer's position from two Moon-star distances, quoting numbers. Even a contrived, fictitious example would be worthwhile. That would allow us to understand where his predicted celestial positions are to come from (for example), how resulting position-lines are to be plotted, how an overall error-budget can be estimated, and whether his estimate of a result to six miles is at all reasonable. Is it necessary to presume an approximate observer's position beforehand? I still look forward to seeing how the job is to be done. George contact George Huxtable at george@huxtable.u-net.com or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---