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    Re: Polaris for Latitude- why so accurate?
    From: Gary LaPook
    Date: 2014 Sep 28, 20:26 -0700
    See also:








    gl






    From: Gary LaPook <NoReply_LaPook@fer3.com>
    To: garylapook---.net
    Sent: Sunday, September 28, 2014 2:40 AM
    Subject: [NavList] Re: Polaris for Latitude- why so accurate?

    I am attaching the current "Q" correction table for Polaris from the 2014 Air Almanac. You enter with the LHA of Aries and 
    take out the correction to find latitude from the altitude of Polaris. See prior post about this here:

    gl





    From: Bill B <NoReply_BillB@fer3.com>
    To: garylapook---.net
    Sent: Saturday, September 27, 2014 9:51 PM
    Subject: [NavList] Re: Polaris for Latitude- why so accurate?

    On 9/27/2014 2:41 PM, Greg Rudzinski wrote:
    > Polaris changes altitude very slowly just like the Sun at or near LAN.
    
    Sam
    
    Currently the declination of Polaris is 89°18.5'N. That means it is
    nominally 41.5' from the north pole. For most of the northern hemisphere
    it is circumpolar, meaning it never dips below the horizon.
    
    If you could view Polaris all day, twice a (sidereal) day it's Hc would
    be exactly  89°18.5'N. Once a day 89°18.5' minus 41.5', and once a day
    89°18.5' plus 41.5'. Azimuth wise, true north twice a day, and off to
    the east or west the remainder of the day. As Greg pointed out, that is
    a relatively slow rate of change.
    
    While it is great you are absorbing Bowditch, there is a table in the
    back of the NA (pages 274-276) that adjusts for the change in altitude
    and azimuth based on LHA Aries, month and latitude. No sight reduction
    required. The NA, one-stop shopping ;-)
    




    Attached File:

    (img/128754.polaris.pdf: Open and save or View online)



       
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