NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Horizontal Parallax
From: Frank Reed
Date: 2014 Nov 24, 10:44 -0800
From: Frank Reed
Date: 2014 Nov 24, 10:44 -0800
Evangelos, you asked:
"For the altitude of moon I should go for an upper/low limb or for the approximate center?"
I didn't specify because it makes no difference. The correction to the HP for the Moon's altitude was 1.1'·sin(Hmoon). Make a list of the values of this correction for every 5° of altitude. That's good enough when we need this correction to the nearest tenth of a minute of arc.
You also wrote:
"I could use the semi-diameter from the angular D I measured ? Since SD from the formula it's proportional to HP and HP is just what I am trying to find."
Yes. That's already incorporated into the little equation I posted yesterday:
HP = 1.836·D - 1.1·sin(Hmoon).
-FER
