A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: William Porter
Date: 2018 Nov 4, 23:51 -0800
Oh man: I have general relativity to worry about?! Thank you Paul; that is seriously helpful. I had no idea the different time standards were observably far apart [to my level of precision]. I really appreciate it.
That closes my last error so that's me pretty well me done, and we can kill this thread; I have learnt a lot: thank you. My ambition is next week (Spode's law permitting) to set my watch using sextant, ephemera and tables only.
Don't worry about Altair; I have got her (hourly!) RA and Dec updated from the J2000 standard from USNO. I assume the answer to my open question about Fred's source is the same, including the polynomials.
The AD is the moon's angular diameter in seconds.
In researching the history of the haversine I found this gem of an old book. Look at p595 (easier after searching on "eclipse"): old school. Amazing. https://books.google.co.uk/books?id=x8cDAAAAMAAJ&pg=PA816&dq=%22squared+sine%22+of+chord&hl=en&sa=X&ved=0ahUKEwiZnMzT4LzeAhXMKcAKHW6yAcIQ6AEIKjAA#v=onepage&q=p596&f=false