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    Re: Hardly ever get an LOP than 20 NM - why?
    From: Laurence Holden
    Date: 2020 Jan 18, 15:21 -0800

    Just recalculated using my Ha (30 degrees/53.5’ as my Ho and got an Intercept of 9’ so I got an LOP that ran by my actual location by just over 6NM. you would think the A2 Altutude correction for atmoshpheric refraction is important. Early on I questioned the effect of this atmospheric refraction (per the A2  altitude correction table) especially as I am located 2100 feet above sea level!  But could not query my way thru that. But there is also the question of the lower limb/upper limb accounted for in that A2 table (and I’m using the whole horizon mirror on my sextant which I’ve assumed gave me the angle of the lower limb)

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