A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2020 Feb 4, 06:44 -0800
This is an extract from the Russian document by Institute of Applied Astronomy of Russian Academy of Science - “The Nautical Astronomical Almanac for the years 2013–2014 biennial (NАА-2) for deck officers".
Shown is a tabular method of solving PZX triangles by dividing into two right-angled ones. For me it looks very similar to Bygrave's approach but math is slightly different. The method was introduced in 1957 by A.P.Yuschenko, professor for naval sciences.
Tabulated values are:
- S(γ) = 2·104·log(1/cos(γ))
- T(γ) = 2·104·log(tan(γ)) + 70725
The "70725" value is the 2·104·log(tan(89°59')), it make all values positive. The explanatory text states that the method is an improvement over some previous one.
Since I did not see the HO-214 tables I'd like some comments about the matters.