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Re: Sight Reduction Formula Question
From: Paul Hirose
Date: 2005 Jan 8, 23:00 -0800
From: Paul Hirose
Date: 2005 Jan 8, 23:00 -0800
Bill wrote: > > A lot for a liberal arts major to follow. My question. Susan Howell states > (for the longer of the two formulas Fried gave) "if sin LHA is less than 0, > Zn = Z, if sin LHA is equal to or greater than 0, Zn = 360 - Z." I don't bother to compute Zn. A glance at the body's LHA reveals whether it's to the west or east, so I write something like Z = 55 W. To plot the LOP, rotate the protractor 55 degrees west of north. The procedure is the same south of the Equator, except that the protractor is rotated 55 degrees west of SOUTH, since Z is always measured from the "elevated pole". Maybe I'm just weird, but I find the above method easier than converting Z to Zn.