NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Randall Morrow
Date: 2014 May 12, 07:38 -0700
Alan,
For question 1: I know which stars I am shoting because of looking at the night sky regularly. After over 5000 observations I can typically pick out 15 or so stars by name, beacuse I know what's in the sky on that day and where to look for it. Constellations help this but also unofficiall shapes in the sky like the "summer triangle" of Vega, Deneb and Altair. Even with a partially clouded sky taking away these reference points, if you see a 1st magitude star peep through in a certain part of the sky, you will know pretty well ahich it is. Of course you'd shoot it anyway, and try to ID it later. I don't own a starfinder but have used Google sky maps and the Celestial Tools programs for planning.
Question 2:
I am forced to use an AH because I live in Bakersfield, 2 hours from the shore.
But I have taken shore sights for the USPS Navigation class sight folder and the results were excellent, (accepted) largely I believe due to lots of AH practice at home.
For star sights you just superimpose the pinpoint of the star in the mirror with the one you bring down. This is why focus is importsnt, because, in my experience, careful focus reduced the flare around the star and decreases the pinpoint diameter. My recent change to placing the mirror on the ground instaed of on a table was done for that reason. It is also a good idea to "rock" the sextant when taking a star sight because one pinpoint looks like the other and the only way to line them up well is to see the "path" of one point pass through the other, rather than above or below. For sun and moon you shoot a tangency of two images and for stars or planets you shoot a superposition of one point on another.
----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------