Re:List of selected stars for navigation
by UI_at_80x24 on Tuesday September 24, 2019 @01:33PM
(#21062601)
This is good to hear so thank-you for writing that.
I have a plan to do a bicycle tour from Canada to Mexico sometime in my retirement years (or sooner). Part of that included a 'Wouldn't it be quaint/interesting' desire to bring along an old sextant I inherited and see how close I could chart my progress to my actual location.
If the charts change that much over time, then this might work the way I was expecting.
Re:List of selected stars for navigation
by gmiller123456 on Tuesday September 24, 2019 @02:12PM
(#21063029)
Sextants aren't really made for use on land, you need a very flat horizon to use one, you can use an "artificial horizon" but you'll loose some accuracy. A sextant is made for observations at sea, where a ship would be bobbing up and down. On steady land, it's much easier to just measure the angle a star makes with a level base. I'm not sure of the exact name, I've seen old telescopes with a protractor on the side, and a level and compass on the base.
But, so long as it's just for fun, you can rely on your phone for updated star information and time.
You can't use static charts because the Earth wobbles a bit (called precession and nutation), and doesn't rotate at a constant speed. This effect can make a difference of being off my many miles just over a year, and 10's of miles over a few years.