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    Re: An azimuth formula that works everywhere? Even on poles?
    From: David Pike
    Date: 2021 Jul 23, 13:48 -0700

    Robin Stuart you wrote: Like you I have been musing on celestial navigation at the poles. What happens if you are at the pole, your tracks have been covered in a blizzard and your watch has stopped? How do you the direction back to the supply dump? I guess you'd have to hope that your magnetic compass can point the way,

    Robin

    You would be describing the South Pole in the summer.  If you were Amundsen, you probably would have ensured you had several spare watches, but let’s suppose they’ve all stopped.  You need a direction to set off to find the most recent of the black flags you’ve carefully left along your outbound track.  In the summer, the Sun would be visible for 24 hours, and would be just spiralling up or down with change of variation.  In the winter it would be easier because the stars would be circling overhead.  For any particular day (if you knew which day it was (shape of the Moon possibly, long wave radio)) you could get a time when two stars were vertically above each other e.g. Canopus above Sirius, or Acrux above Gacrux.  Once you’ve got time, you’ve got direction.  There are only two problems.  1.  You’ve already frozen to death or died of starvation.  2.  Your unlikely to see your black flags.  Therefore, we’re back looking at summer.

    As a member of the RIN you’ll be aware that there was an animal navigation paper a couple of years ago suggesting that dogs preferred to go to stool along a north south axis, but this was thought to be something to do with magnetism, so the best it could give you is a 50% chance of knowing the rough direction of the Magnetic South Pole.  However, fear not.  The Magnetic South Pole (MSP) is almost 3000km from the South Pole, so the chances are that you’ll get an acceptable response from your compass, and if you’ve got the MSP marked on your chart, you’ve got direction.  Apart from that, I’m still thinking about it.  DaveP

       
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