astro::rise_set::moon Namespace Reference

Lunar conventions and entry points: the Ch.15 standard altitude and the UT-day (almanac-style) API wired to the ELP2000-82B ephemeris. More...

Functions
auto	horizontal_parallax (const double jde_tt) -> toolbox::AngleRad
	The Moon's equatorial horizontal parallax Π at one instant.
auto	h0 (const toolbox::AngleRad &Π, const astro::earth::refraction::Params &p={}) -> toolbox::AngleDeg
	The standard altitude of the Moon's center at rise/set: 0.7275·Π − refraction.
auto	calculate (const std::chrono::year_month_day &ymd_ut1, const GeoLocation &location, const astro::earth::refraction::Params &p={}) -> Result
	Compute moonrise, lunar transit, and moonset for one UT1 calendar day.

Variables
constexpr auto	apparent_equatorial
	The Moon's position provider: apparent geocentric equatorial coordinates at one instant (TT) — an alias of astro::moon::equatorial_coord::apparent, the lunar counterpart of the solar provider.

Detailed Description

Lunar conventions and entry points: the Ch.15 standard altitude and the UT-day (almanac-style) API wired to the ELP2000-82B ephemeris.

Function Documentation

calculate()

auto astro::rise_set::moon::calculate ( const std::chrono::year_month_day & ymd_ut1, const GeoLocation & location, const astro::earth::refraction::Params & p = {} )->Result

inlinenodiscard

Compute moonrise, lunar transit, and moonset for one UT1 calendar day.

Parameters

ymd_ut1	The date, interpreted on the UT1 scale (callers handle time zones).
location	The observer's location.
p	The atmospheric refraction parameters for the h₀ convention (defaults: standard 34′).

Returns

The events inside the UT day and the polar topology. Any instant may be absent — with lunar transits ~24.84 h apart, a UT date without a moonrise (or without a transit) is routine, and that absence must not be read as a polar verdict; check polar for the topology. On double-event days (the Moon can rise or set twice in one UT day at high latitudes near a standstill) the LATER event is reported; see calculate_day's note.

Exceptions

std::invalid_argument	If ymd_ut1 is invalid, location is out of range, or p is invalid (see refraction::at_horizon), or a time conversion leaves its supported years.
std::runtime_error	For a refraction failure at the h₀ stage (see h0's @throw — e.g. SAEMUNDSSON non-convergence), or numerical failures inside calculate_day (see its @throw).

Note

h₀ is evaluated with Π taken at mid-day (see h0's note for the error budget).

The window is the UT1 calendar day, matching almanac (e.g. USNO rstt/oneday at tz=0) cell semantics — unlike the solar API, which is transit-centered.

h0()

auto astro::rise_set::moon::h0 ( const toolbox::AngleRad & Π, const astro::earth::refraction::Params & p = {} )->toolbox::AngleDeg

inlinenodiscard

The standard altitude of the Moon's center at rise/set: 0.7275·Π − refraction.

Parameters

Π	The equatorial horizontal parallax at (approximately) the event time. A per-day value is sufficient: Π's intra-day drift moves rise/set instants by seconds at most, invisible to the minute-level golden contract (enforced end-to-end by the golden tests).
p	The atmospheric refraction parameters. Defaults reproduce Meeus's 34′ term.

Returns

The geometric altitude of the Moon's center that makes its upper limb appear at the horizon. The 0.7275 factor folds the parallax (and the upper-limb semidiameter) into the horizon dip, so geocentric coordinates can be used directly — no topocentric reduction (Ch.40) is needed at minute-level accuracy.

Exceptions

std::invalid_argument	If p is invalid (see refraction::at_horizon).
std::runtime_error	For Model::SAEMUNDSSON, if the horizon iteration does not converge (see refraction::at_horizon).

See also

Jean Meeus, "Astronomical Algorithms", Second Edition, Chapter 15.

horizontal_parallax()

auto astro::rise_set::moon::horizontal_parallax ( const double jde_tt ) ->toolbox::AngleRad

inlinenodiscard

The Moon's equatorial horizontal parallax Π at one instant.

Note

Geocentric distance from the ELP2000-82B ephemeris; see moon::geocentric_coord::equatorial_horizontal_parallax.

Variable Documentation

apparent_equatorial

auto astro::rise_set::moon::apparent_equatorial

inlineconstexpr

The Moon's position provider: apparent geocentric equatorial coordinates at one instant (TT) — an alias of astro::moon::equatorial_coord::apparent, the lunar counterpart of the solar provider.