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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Longitude by compass variation
From: Lars Bergman
Date: 2025 Jun 18, 23:30 -0700
From: Lars Bergman
Date: 2025 Jun 18, 23:30 -0700
Robin,
I think Polaris was used for latitude determination only; measuring the bearing of that star at 55°N cannot be easy. Then the azimuth was determined when the sun's true altitude equalled 0°.
Using an approximative local hour angle of Polaris would give sufficient accuracy for the term p·cos LHA used to calculate latitude, where p is the polar distance.
Lars
