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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Old style lunar
From: Ken Muldrew
Date: 2004 Dec 8, 21:21 -0700
From: Ken Muldrew
Date: 2004 Dec 8, 21:21 -0700
Earlier in the week, Alex wrote: > Can you send me (or post) specific numbers and details? > I mean what was the actual distance, GMT and your coordinates, > what was your > measured > distance, IC, what sextant did you use etc. > > (I am not only interested for the purpose of this discussion > but I also want to compare my own results with other people's > results). I've copied my notes from a lunar that I did in the spring. It is actually more tedious and time consuming to type this stuff in than it is to work the lunar the old fashioned way with pencil and paper. It's not really like an old-style lunar since my watch was set to zone time and I knew where I was. I did a few of these using my own data (and some more using historical data) to learn what was involved (the mechanics of the process). I became very busy with several things at the start of summer so the few lunars I've shot since spring have only been reduced briefly by computer; sometimes I just plot the data to have a look (and sometimes I just leave the numbers in my notebook). Below I take a time sight and 2 lunars. The lunars are worked using Witchell's method. Alex, it would be hard to notate this without writing a chapter on the subject, but please feel free to ask any questions you might have. Lunar - May 1, 04 T = 12?C IE = 8.4' Regulus Regulus to )) NL time dist 10:06:35 36?18.5' 08:00 19.4' 08:50 19.9' 09:40 20.1' 10:55 20.4' ------------------------- 260 114 175 60 125 30 75 18 0 0 ------ ------- 1270 444 -------------------------- 10:08:48 36?19'40" Pollux to )) NL 10:13:50 72?46.2' 15:05 46.9' 16:15 47.3' 17:15 48.0' 18:15 48.8' ------------------------- 265 156 190 114 120 90 60 48 0 0 ------ ------- 1270 816 -------------------------- 10:16:08 72?47'26" Venus altitude 10:22:34 41?18.0' 24:58 40?51.8' 25:09 31.9' 26:17 10.5' 27:55 39?42.2' ------------------------- 321 95.8 237 69.6 166 49.7 98 28.3 0 0.0 ------ ------- 1644 486.8 ------------------------- 10:25:11 40?30'53" - 8.4' --------- 40?22'29" /2 --------- 20?11'15" refraction = -2.6' Ho = 20?8.7' Almanac data for 10:25:11 MDT, 04:25:11 GMT (May 2) Venus decl 27?46.3' Polar dist 62?13'41" Time sight: Latitude 51?05'00" Ho 20?08'42" 1/2 lat + Ho 35?36'50" ctn 10.14491 ----------- difference 15?28'08" tan 9.44207 1/2 PD 31?06'50" ctn 10.21927 -------- 32?37'19"