moon_sighting 1.0.0

Lunar crescent visibility for Dart and Flutter. Moon phase, position, illumination, and Yallop/Odeh visibility criteria using Meeus algorithms. Zero dependencies.

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog.

1.0.0 - 2026-03-08

Added

• getMoonPhase() returns phase name, emoji symbol, illumination percentage, age in hours, elongation, waxing/waning state, and next/previous new moon and full moon dates
• getMoonPosition() returns topocentric azimuth, altitude (with Bennett refraction), geocentric distance, and parallactic angle for any observer location
• getMoonIllumination() returns illumination fraction, phase cycle position, bright limb position angle, and waxing/waning indicator
• getMoonVisibilityEstimate() computes Odeh crescent visibility criterion (V parameter, zones A through D) from approximate Meeus positions at a given observation time
• getMoon() combined snapshot bundling all four functions in a single call
• arcvMinimum() the Odeh 2006 polynomial for minimum arc of vision as a function of crescent width
• Meeus Ch. 25 Sun position (geocentric, < 0.01 deg accuracy)
• Meeus Ch. 47 Moon position with 30 longitude terms and 20 latitude terms (< 0.3 deg accuracy)
• Meeus Ch. 49 new moon and full moon time estimation (within ~2 hours)
• Full delta-T polynomial (Espenak & Meeus, piecewise by year)
• Leap-second table through 2017 Jan 1 (37 seconds)
• WGS84 geodetic to ECEF conversion
• Bennett (1982) atmospheric refraction with pressure/temperature correction
• Simplified GCRS to ITRS frame rotation via Earth Rotation Angle (sufficient for lite-mode ~1 deg accuracy)
• Yallop q-test with categories A through F (NAO Technical Note 69)
• Odeh V-parameter with zones A through D (Experimental Astronomy 2006)
• Input validation for latitude, longitude ranges
• Complete type system: MoonPhaseResult, MoonPosition, MoonIlluminationResult, MoonVisibilityEstimate, MoonSnapshot, YallopResult, OdehResult, CrescentGeometry