NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: John D. Howard
Date: 2015 Jun 5, 09:18 -0700
Hello All,
Andres's post got me to thinking, nobody seems to use the JPL Horizons system to get Almanac data.
There has been talk of long term almanacs but the JPL system will generate an ephemeride list for the sun,moon, any planet of your choosing for any time intervial and length. I downloaded a " emergency lifeboat almanac " to a text file for every six hours from 2010 untill 2023. You can change what the file contains but I chose Sideral time, RA and Dec for the sun and Local Apperent Time. Using 0 N and 0 W as location I have a small file that will give me GHA Aries ( sid time ) the Dec of the sun and the Equation of Time ( time - local apperent time ).
It is very easy to print out six month or so when you leave home and put the several pieces of paper into your sextant box.
That along with Hanno's great haversine table is all you need to do sight reductions.
John H.
