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    Is there any connection between difference in SHA and difference in azimuth?
    From: David Pike
    Date: 2017 Sep 25, 00:52 -0700

    Last night in a post, I speculated that you could get a rough idea of the difference in azimuth of stars by examining their difference in SHA.  I wasn’t entirely happy with that statement, hence my use of the word ‘roughly’.  This was not a good problem to go to bed with.  After much thought, I concluded that it might only be true close to the poles.  Study of AP3270/HO249 Vol 1 this morning shows this is true at the poles but gets progressively more untrue the further from the poles you travel.  By the time you get to the latitude of Belgium it’s not much use.  Even the difference of the differences isn’t constant.

    Perhaps one of our spherical geometry experts might explain the true relationship, if any.  DaveP

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