NavList:

Hello:

I first learned to do this calculation in FER's Mystic class using LMT
and with the adjustment for the equation of time. The relevant equation
is Cos LHA = (Sin HO - sin Lat x sin decl)/(cos Latx cos decl). Must start with a known latitude.

It seems it is even simpler using GHA, so I used some of my recent data as an problem. Here is the sight data: location 41 d 55'N 69d 58' W; I'm at the site of the original Marconi Station in south Wellfleet,MA , looking east to a rising sun.

Local corrected time 08:11:09 EDT ( 12:11:09 GMT), GHA = 2d 6'; HO = 24 d 07' , decl = N 11d 32.4'. Solving for LHA I calculated LHA = 67 d 51'. All straight forward. I tried to use basic equation: GHA = LHA + wlong ..... gave up and made a sketch. Longitude = 67d 51' + 2 d 6'= longitude of 69 d 57'. Good.

Can someone explain the sign and angle to use for LHA in this application? What is the best way to do this?

Thanks
Bruce
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