"Walt" wrote:

On Apr 4, 7:57 am, "Jim" wrote:
More importantly - can anyone list a website that explains:

1. how \ where to find those 57 stars and
2. how to use them for navigation

I was only aware of polaris, the southern cross and orion's belt as
navigational stars.

When I was flying KC-135's in the '70's we used celestial navigation
on overwater flights.

IIRC you should be able to find the lists in either the Air Almanac
(most likely) or the H.O. 249 sight reduction tables. Probably doesn't
help the nautical guys any but I don't have any experience in that
area.

The ideal solution is to get a three-star fix. Each star shot gives
you a single line of position (LOP) and a three-star fix (using stars
spaced correctly in the sky) would give you three LOP's, and when
plotted on a chart would form a small triangle. Your position should
be somewhere inside that triangle, so the smaller the triangle the
better.

That, combined with your DR position you plotted from your last fix
using best-known winds will give you a pretty accurate position.

In the daytime, where only the sun (and maybe the moon) could be seen
you would usually get only a single line of position. On an east-west
flight that LOP would be a speed line in the morning/evening and a
course line in the middle of the day. On a typical 6-8 hour flight
from, say, Hickam AFB in Hawaii to Anderson AFB in Guam you'd get both
over the course of a flight.

Sometimes in the daytime you could see Venus through the sextant (we
used a periscopic bubble sextant) but it could be a challenge.

And doing it in a fast aircraft one is really bedevilled by factors
that us sailors thankfully don't suffer. Like the coriolus effect on
the bubble in the sextant and postion lines many miles apart that have
to be transferred with drift guessed at etc.
At sea, given the right conditions, a bit of luck and lots of skill
one could plot a position within half a mile. I hate to think what
sort of error air navigators had! As they said in World War two -
celestial navigation is best left to the birds! That's why electronic
navigation aids were such a priority.

Eugene L Griessel

The basic delusion that men may be governed and yet be free.