NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: LAN sight help !!
From: Millard Kirk
Date: 1999 Aug 14, 4:54 PM
From: Millard Kirk
Date: 1999 Aug 14, 4:54 PM
Hi Barry,
I'm trying to learn Celestial Nav on my own and I have a question
regarding LAN sights...I understand the concept, the math and the
conversion of ARC time.BUT for instance:
mer pass + DR-LON(W) = GMT of LAN
12h 06m + 8h 09m 12s = 20h 15m 12s
How does 20h 15m 12s help me in predicting LAN at my long....Is it
that simple that I just don't see it..???
---------------------------------------------------
Ahhhhhhh!!!!!!!!! Email and errors. Correction on my last post... I
hope there are no more in here.......
Looks as if you have the right answer but, can't see it. Just subtract 8h
from 20h 15m 12s and you have your LAN.
Back calculating from 8h 09m 12s time at DR-LON(W) your LON is 122 18min
(typo last post)
From your mer pass data I know that the sun will pass over
Longitudes of 0, 15, 30, 45, 60, 75, 90, 105, 120, .... 180 at 12:06 Zone
Time. If you were at 120d exactly then the sun would pass over you at 12h
06m, but you are 2d 18min W of 120d therefore it will take the sun a little
longer to get directly overhead of you. The sun travels 1 degree in 4
minutes. So you are 2d 18min= 2.3d West of 120.
2.3d X 4 m/d = 9.2m or 9m 12s.
You just add the 6m from the mer pass to 9m 12s and you get 15m 12s after
12:00 or LAN = 12h 15m 12s.
Or am I missing something???
Still...............
Learning the Hard Way!!
Millard Kirk KB8YQO | mailto:mkirk@marshall.edu
116 Lewis Ave | http://webpages.marshall.edu/~mkirk/
Barboursville, WV | A West Virginia Blue Water Sailor
25504 | Phone: (304) 736-6544
| First United Methodist Church,
Barboursville, WV
| Homepage
http://www.gbgm-umc.org/bfumcwv/
