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    Re: V-Correction for Sun? Answer from UKHO...
    From: David Pike
    Date: 2016 Oct 13, 16:58 -0700

    Axcel.  John H and Gary L are correct.  It really is horses for courses.  I shot celestial for 13 years, and I don’t remember anyone ever mentioning V corrections.  If they did, I must have been asleep that day.  Mind you, we were using the “Air Almanac” which has ten minute values of GHA and declination, and I had four other guys to make sure I shot on a ten minute time, so I rarely had to convert arc to time or vice versa.  
    I think you’re worrying unnecessarily.  As John hints, a 0.25 minute of arc error in GHA doesn’t correspond to a 4nm position line (PL) error at the Equator. 

    Off the top of my head, 1 degree error in GHA would correspond to 60nm East or West error in a PL at the Equator. 

    Therefore, one minute of arc error in GHA would correspond to 1nm E-W error in the same PL, and 0.25 minutes of arc would correspond to 0.25nm E-W error. 

    As the latitude increases the error in nm from ignoring V correction will be less, and the further away the azimuth is from E or W the effect of any particular error on the observer’s position will be less.  If we ended a celestial exercise within 3nm of our declared finishing point, we thought we were doing pretty well, but it really is horses for courses.  DaveP

       
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