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Re: Lunars -Venus!
From: Frank Reed CT
Date: 2004 Apr 23, 22:05 EDT
From: Frank Reed CT
Date: 2004 Apr 23, 22:05 EDT
Jim T wrote:
"Venus/Moon
WT 22h 00m 21s
WE 08s fast
ZD +4-1 for DST = +3
IE 2.7' on the arc
hs 5d 57.1'
GPS Fix:
46d 16' 37.4" N
063d 10' 48.8" W"
I worked up your lunar based on the information you provided, and it turns out that your longitude by lunar is 063d 10' 48.81" W. Not bad!!
<g>
Sorry, I couldn't help being entertained by the contrast in accuracy between your GPS numbers (0.1" in latitude is about ten feet) and the potential accuracy of a lunar distance longitude. Anyway, I did work your lunar just now (using my calculator at www.clockwk.com/cell/lunars.html , which is based structurally on Arthur Pearson's spreadsheet, and using almanac data from Omar Reis's online almanac) and the result indicates that your observation was short by about 3 minutes of arc. Did you use a shade to make Venus less dazzling? That 3 minute error corresponds to about 1.5 degrees error in longitude which puts you at sea off Inverness, Nova Scotia. Of course my clearing procedure may be in error. I just worked it up quick.
Frank E. Reed
[ ] Mystic, Connecticut
[X] Chicago, Illinois
"Venus/Moon
WT 22h 00m 21s
WE 08s fast
ZD +4-1 for DST = +3
IE 2.7' on the arc
hs 5d 57.1'
GPS Fix:
46d 16' 37.4" N
063d 10' 48.8" W"
I worked up your lunar based on the information you provided, and it turns out that your longitude by lunar is 063d 10' 48.81" W. Not bad!!
<g>
Sorry, I couldn't help being entertained by the contrast in accuracy between your GPS numbers (0.1" in latitude is about ten feet) and the potential accuracy of a lunar distance longitude. Anyway, I did work your lunar just now (using my calculator at www.clockwk.com/cell/lunars.html , which is based structurally on Arthur Pearson's spreadsheet, and using almanac data from Omar Reis's online almanac) and the result indicates that your observation was short by about 3 minutes of arc. Did you use a shade to make Venus less dazzling? That 3 minute error corresponds to about 1.5 degrees error in longitude which puts you at sea off Inverness, Nova Scotia. Of course my clearing procedure may be in error. I just worked it up quick.
Frank E. Reed
[ ] Mystic, Connecticut
[X] Chicago, Illinois
