Phase lunaire API

Vous pouvez calculer vous-même assez facilement

• http://www.phpclasses.org/package/1201-PHP-Calculates-the-phase-of-the-Moon.html
• http://jivebay.com/calculating-the-moon-phase/

Prises de wxforums.net, affichage par "Cristian"

<?php
/*
Adaptation en php du fameux et excellent scripte Astro-MoonPhase de Brett Hamilton écrit en Perl.
http://search.cpan.org/~brett/Astro-MoonPhase-0.60/
Ce Scripte vous permettra de connaître, à une date donnée, l'illumination de la Lune, son age, 
sa distance en km par rapport à la Terre, son angle en degrés, sa distance par rapport au soleil, 
et son angle par rapport au soleil.
*/
class Moon
{
function phase($Year, $Month, $Day, $Hour, $Minutes, $Seconds)
{
$DateSec = mktime($Hour, $Minutes, $Seconds, $Month, $Day, $Year, 0);
ini_set(precision, "20");   //Defini la precision des calcules
# Astronomical constants.
$Epoch                  = 2444238.5;        # 1980 January 0.0
# Constants defining the Sun's apparent orbit.
$Elonge                     = 278.833540;       # ecliptic longitude of the Sun at epoch 1980.0
$Elongp                     = 282.596403;       # ecliptic longitude of the Sun at perigee
$Eccent                     = 0.016718;             # eccentricity of Earth's orbit
$Sunsmax                = 1.495985e8;       # semi-major axis of Earth's orbit, km
$Sunangsiz              = 0.533128;             # sun's angular size, degrees, at semi-major axis distance
# Elements of the Moon's orbit, epoch 1980.0.
$Mmlong                     = 64.975464;        # moon's mean longitude at the epoch
$Mmlongp                = 349.383063;       # mean longitude of the perigee at the epoch
$Mlnode                     = 151.950429;       # mean longitude of the node at the epoch
$Minc                   = 5.145396;             # inclination of the Moon's orbit
$Mecc                   = 0.054900;             # eccentricity of the Moon's orbit
$Mangsiz                = 0.5181;           # moon's angular size at distance a from Earth
$Msmax                  = 384401.0;             # semi-major axis of Moon's orbit in km
$Mparallax              = 0.9507;           # parallax at distance a from Earth
$Synmonth               = 29.53058868;      # synodic month (new Moon to new Moon)
$pdate = Moon::jtime($DateSec);
$pphase;                # illuminated fraction
$mage;                  # age of moon in days
$dist;                  # distance in kilometres
$angdia;                # angular diameter in degrees
$sudist;                # distance to Sun
$suangdia;              # sun's angular diameter
# Calculation of the Sun's position.
$Day = $pdate - $Epoch;                                         # date within epoch
$N = Moon::fixangle((360 / 365.2422) * $Day);               # mean anomaly of the Sun
$M = Moon::fixangle($N + $Elonge - $Elongp);                # convert from perigee
# co-ordinates to epoch 1980.0
$Ec = Moon::kepler($M, $Eccent);                            # solve equation of Kepler
$Ec = sqrt((1 + $Eccent) / (1 - $Eccent)) * tan($Ec / 2);
$Ec = 2 * Moon::todeg(atan($Ec));                           # true anomaly
$Lambdasun = Moon::fixangle($Ec + $Elongp);                     # Sun's geocentric ecliptic
# longitude
# Orbital distance factor.
$F = ((1 + $Eccent * cos(Moon::torad($Ec))) / (1 - $Eccent * $Eccent));
$SunDist = $Sunsmax / $F;                                   # distance to Sun in km
$SunAng = $F * $Sunangsiz;                                  # Sun's angular size in degrees
# Calculation of the Moon's position.
# Moon's mean longitude.
$ml = Moon::fixangle(13.1763966 * $Day + $Mmlong);
# Moon's mean anomaly.
$MM = Moon::fixangle($ml - 0.1114041 * $Day - $Mmlongp);
# Moon's ascending node mean longitude.
$MN = Moon::fixangle($Mlnode - 0.0529539 * $Day);
# Evection.
$Ev = 1.2739 * sin(Moon::torad(2 * ($ml - $Lambdasun) - $MM));
# Annual equation.
$Ae = 0.1858 * sin(Moon::torad($M));
# Correction term.
$A3 = 0.37 * sin(Moon::torad($M));
# Corrected anomaly.
$MmP = $MM + $Ev - $Ae - $A3;
# Correction for the equation of the centre.
$mEc = 6.2886 * sin(Moon::torad($MmP));
# Another correction term.
$A4 = 0.214 * sin(Moon::torad(2 * $MmP));
# Corrected longitude.
$lP = $ml + $Ev + $mEc - $Ae + $A4;
# Variation.
$V = 0.6583 * sin(Moon::torad(2 * ($lP - $Lambdasun)));
# True longitude.
$lPP = $lP + $V;
# Corrected longitude of the node.
$NP = $MN - 0.16 * sin(Moon::torad($M));
# Y inclination coordinate.
$y = sin(Moon::torad($lPP - $NP)) * cos(Moon::torad($Minc));
# X inclination coordinate.
$x = cos(Moon::torad($lPP - $NP));
# Ecliptic longitude.
$Lambdamoon = Moon::todeg(atan2($y, $x));
$Lambdamoon += $NP;
# Ecliptic latitude.
$BetaM = Moon::todeg(asin(sin(Moon::torad($lPP - $NP)) * sin(Moon::torad($Minc))));
# Calculation of the phase of the Moon.
# Age of the Moon in degrees.
$MoonAge = $lPP - $Lambdasun;
# Phase of the Moon.
$MoonPhase = (1 - cos(Moon::torad($MoonAge))) / 2;
# Calculate distance of moon from the centre of the Earth.
$MoonDist = ($Msmax * (1 - $Mecc * $Mecc)) /
(1 + $Mecc * cos(Moon::torad($MmP + $mEc)));
# Calculate Moon's angular diameter.
$MoonDFrac = $MoonDist / $Msmax;
$MoonAng = $Mangsiz / $MoonDFrac;
# Calculate Moon's parallax.
$MoonPar = $Mparallax / $MoonDFrac;
$pphase = $MoonPhase;                                   # illuminated fraction
$mage = $Synmonth * (Moon::fixangle($MoonAge) / 360.0);     # age of moon in days
$dist = $MoonDist;                                      # distance in kilometres
$angdia = $MoonAng;                                         # angular diameter in degrees
$sudist = $SunDist;                                         # distance to Sun
$suangdia = $SunAng;                                    # sun's angular diameter
$mpfrac = Moon::fixangle($MoonAge) / 360.0;
return array( $pphase, $mage, $dist, $angdia, $sudist, $suangdia, $mpfrac, $mpfrac );
}
function fixangle($x)   { return ($x - 360.0 * (floor($x / 360.0))); }  # fix angle
function torad($x)  { return ($x * (M_PI / 180.0)); }               # deg->rad
function todeg($x)  { return ($x * (180.0 / M_PI)); }               # rad->deg
function jtime($t)
{
$julian = ($t / 86400) + 2440587.5;     # (seconds /(seconds per day)) + julian date of epoch       2440587.5 /86400 = 28,24753472222 Days
return ($julian);
}
function kepler($m, $ecc)
{
$EPSILON = 1e-6;
$m = Moon::torad($m);
$e = $m;
while (abs($delta) > $EPSILON)
{
$delta = $e - $ecc * sin($e) - $m;
$e -= $delta / (1 - $ecc * cos($e));
}
return ($e);
}
}
//Exemple d'utilisation :
//Pour le 11 Avril 2009 à 00h00
list($MoonPhase, $MoonAge, $MoonDist, $MoonAng, $SunDist, $SunAng, $mpfrac) = Moon::phase(2009, 04, 11, 00, 00, 01);
echo "La Lune est éclairée à ".number_format($MoonPhase*100, 2, ',', '')."%"."<br>";
echo "Son age est de ".number_format($MoonAge, 0, ',', '')." jours"."<br>";
echo "Et elle se situe à une distance de ".number_format($MoonDist, 0, ',', '')." km par rapport à la Terre."."<br>";
?>

OriginalL'auteur Mark Baker