From 90c493642799fe9df02712bea45d391db3ecee58 Mon Sep 17 00:00:00 2001 From: Aric Camarata Date: Sun, 8 Mar 2026 17:19:53 -0400 Subject: [PATCH] docs: add Architecture and Acknowledgments sections; rename Related Packages to Related --- README.md | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index 009bb88..9ac1ad1 100644 --- a/README.md +++ b/README.md @@ -132,19 +132,34 @@ This Dart package implements lite mode only. It covers moon phase, position, ill The full-mode features (DE442S JPL ephemeris, sub-arcsecond accuracy, rise/set event finding, best-time optimization, full sighting reports) are available in the TypeScript package. +## Architecture + +Two-mode design: lite mode uses Jean Meeus Chapters 47 and 48 for moon phase, position, and illumination — zero dependencies, no file I/O, works in any Dart environment. The GCRS-to-topocentric conversion applies ERA-only Earth rotation (no full nutation/precession), which introduces a ~1 degree systematic error acceptable for display and quick-estimate use cases. + +Full-mode features (DE442S ephemeris, sub-arcsecond accuracy, rise/set event finding) are in the TypeScript [moon-sighting](https://github.com/acamarata/moon-sighting) package. + ## Compatibility - Dart SDK >= 3.7.0 - Works in Flutter, Dart CLI, and server-side Dart - Zero runtime dependencies -## Related Packages +## Related - [moon-sighting](https://github.com/acamarata/moon-sighting) (TypeScript) - Full-accuracy lunar crescent visibility with DE442S ephemeris - [nrel-spa](https://github.com/acamarata/nrel-spa) (TypeScript) - Pure JS NREL Solar Position Algorithm - [pray-calc](https://github.com/acamarata/pray-calc) (JavaScript) - Islamic prayer time calculation - [luxon-hijri](https://github.com/acamarata/luxon-hijri) (TypeScript) - Hijri/Gregorian calendar conversion +## Acknowledgments + +Crescent visibility criteria implemented from: + +- B.D. Yallop, "A Method for Predicting the First Sighting of the New Crescent Moon," NAO Technical Note No. 69, 1997. +- M.Sh. Odeh, "New Criterion for Lunar Crescent Visibility," Experimental Astronomy 18(1), 39-64, 2006. + +Meeus positions from: Jean Meeus, "Astronomical Algorithms," 2nd ed., Chapters 47 and 48. + ## License MIT