A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2018 Apr 19, 10:44 -0700
I'm having difficulties understanding the moonrise/moonset calculation explanations given in the AA's article on page A10, clause 12. When I try to follow the Examples there I get completely puzzled.
- the moonrise for 55°N must be interpolated - I almost agree that the 09:36 is the correct value of the event time, but why did not they interpolate the "diff" value as well?
- how do I get the example-given "-10" value from the F4 flap table? I far as I can see - I must interpolate there too and the value should come out less than the "10" - I entered the F4 table with "9" as the "diff" and the cell I must look-up is in the upper-left direction from the tabulated values
- I can't see why there is no moonset on Jan 23rd: when I subtract 0h40m from the Jan 24th 00:18 I get Jan 23rd 23:38
Could someone please help me through this calculation?
Thank you in advance.