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During the day, can you see polaris? If you only have the sun as a reference you will need a 2nd reference to know where you are. Magnetic north would be easily
by loonster 5y ago
During the day, can you see polaris? If you only have the sun as a reference you will need a 2nd reference to know where you are. Magnetic north would be easily available.
For celestial objects, The math is rather simple. It is the intersection of 2 circles. The refence between the two objects would resolve which intersection is the correct one.
For magnetic north and 1 celestial object, the math is much more complex. Magnetic declination changes depending on where you are. You have to know roughly where you are before you start using it.
- beerandt 5y agoYou can see Polaris with the right equipment, meaning an eye adjusted to darkness, and a filter on your optics. It's always above the horizon in the Northern hemisphere, even during the day. (Same goes for the Southern cross in the Southern hemisphere.) Polaris is important because it doesn't move, relative to the rest of the sky rotating around it. You measure the angle from Polaris to geodetic "up" and that's the complimentary angle to your latitude. There is no complex math, just 90-x=y If you have the time in London, and can observe the sun at its peak (solar noon) then you have longitude (after converting hours to degrees, and keeping minutes and seconds). Or with an almanac, you can measure pretty much any known ID'd star or the sun at any time, and look up longitude from that. Reinventing the wheel isn't needed, it's been the same process for centuries.