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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Haversines with Logarithms
From: David C
Date: 2020 Oct 19, 14:14 -0700
From: David C
Date: 2020 Oct 19, 14:14 -0700
Further to comments about right ascension.
Remember that the time sight formula does not give LHA. It gives the meridian angle t which is measured east or west from noon. LHA is measured west.
AM LHA = 360 - t
PM LHA = t
Right ascension is measured east from aries. Before the introduction of the GHA almanac in the early 1950s the almanac gave RA and EOT. For one or two decades (1930/40s ??) the almnac gave instead factors R and E which were RA and EOT with +- 12 hours added. The GHA almanac makes things very easy.
