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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Martin Caminos
Date: 2024 Jun 9, 19:58 -0700
Hello everyone,
This week I am in Cusco, Peru with the objective of visiting the Machu Picchu later this week.
Earlier today, I took the advantage of the clear skies at Cusco to shoot some lunars with the Mark II sextant I brought with me.
The results obtained with the Lunar Analyzer application were quite satisfactory, with an error of just 0.5’ of arc. (see attached the results)
Cusco is at an altitude of around 10,000 feet, so what I really want to highlight here is the strong influence of the low pressure (around 688 mbars) as well as the Hight of Observer (3.4 km) on the calculation precision.
According to what I learned last week at the Lunars’ seminar with Frank, the pressure has a direct influence on the refraction correction, while the altitude of the observer would influence both the parallax and semi diameter corrections.
As usual, I would open these two topics for comments to make sure I am getting the right conclusions.
Thanks, Martin
(from Cusco, Peru)
