A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2015 May 25, 02:16 -0700
When I was shooting astro, the UK Air Almanac (issued free to RAF Navigators every six months) contained several pages of circles showing the positions of the navigational stars for a particular date and times. I believe they also contained the position of the moon and the planets to avoid moon glow and misidentification. You just laid your protractor on the appropriate diagram and picked a suitable fore and aft star and beam star if you were sandwich fixing, or thee stars at approximately 120° apart if you were 3 PL fixing. With a periscopic sextant, you didn’t need to identify the stars. You just set up the HS and azimuth and shot the brightest star in the eyepiece, although I vaguely remember there were also pictures of the expected view of each star through a 2° field of view periscopic sextant. With a MkIX sextant it was harder, because you had to identify the star first. Fortunately, you only came across MkIXBMs and astrodomes during basic training on Valettas and Varsities.
Please can someone tell me if those diagrams are still in the air almanac and possibly provide a picture, because I can’t remember what the parameters were for selecting the correct diagram. Dave