NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Sean C
Date: 2021 Mar 4, 18:43 -0800
Joshua,
You wrote:
"I am curious about how you went about making your Polaris tables. I have read through the Astronomical Almanac and the Explanitory Supplement but it just dif not 'click' in my head well enough to construct long term tables."
The table I made is not really "long-term". It's just an updated version of table 6 in Pub 249. It should be usable for at least a few years, though.
I made it by using my spreadsheet to calculate the altitude of Polaris at a given location (45°N, 0°E - to be exact) and the GHA of Aries for each minute of January 1st, 2021. Then, I simply subtracted the latitude from the altitude and reversed the sign. Since the longitude is 0°, the GHA of Aries is also the LHA.
I have attached the table below. I will probably recalculate it for some date in the future before I am done. That way, it should be usable for a bit longer.
Cheers!
Sean C.
