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Re: Non moving Observer position from H culm and UT culm
From: Bill Ritchie
Date: 2023 Dec 3, 14:41 -0800

Bonjour Antoine,

You quoted Frank's comment "I'm sure if any of our math-y contributors ponder it for a while, we'll see several ways to do it."

The excellent paper “Position from Observation of a Single Body” by JAMES N. WILSON has much to say on this subject. It is available in NavList Archives. http://fer3.com/arc/imgx/v32n1-6.pdf . The last formula in Appendix 1 neatly combines declination rate and observer northings into a single parameter. It avoids iteration, though I find your iterative method fascinating.

Δt = 10,800 * (Sn - d) * (tan Lat - tan Dec) / (π * (ΔLHA)²)

I used it in my JavaScript code (which includes Lower Meridian Passage). The source is available here, the relevant file being “MeridianPassage.js”. External functions are in other modules, but all can be found with a good editor in the built file "Astron.js".

Bill

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