A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2020 Apr 11, 13:26 -0700
Dear Antoine, huge thanks for your interest in my session log!
1) Ha is the Apparent Altitude, i.e. the value corrected for the index error and dip of the horizon. Ho is the geocentric altitude - i.e. corrected for the refraction, parallax and semi-diameter. I used the A2 table - the combined Refraction and SD corrections - for the Sun. for Venus I used the "STARS AND PLANETS" column;
2) yes, those two equal Ha's one minute apart - are NOT typos, as I said earlier, the horizon is rather difficult to see at some certain azimuths, and I thought it could be the mer-pass. One typo is in the Ho: both values should be 55°10,4';
3) my actual position was 60°10,3'N 29°48,5'E (according to my smartphone's GPS info - I've waited several minutes for it to "settle-in"). The UTs are taken from a Casio with the known watch-error (by listening to the RWM station);
4) though I used the A4 table for the additional corrections to the refraction for the air-temp and pressure - I'm not sure they are adequate for the actual weather of the date. I suspect it could be for more moderate climates than what we have here|now at 60°N30°E.
Thank you again! I'm studying your document right now.