Java tutorial
/** * Copyright (c) 2014,2018 Contributors to the Eclipse Foundation * * See the NOTICE file(s) distributed with this work for additional * information regarding copyright ownership. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License 2.0 which is available at * http://www.eclipse.org/legal/epl-2.0 * * SPDX-License-Identifier: EPL-2.0 */ package org.eclipse.smarthome.binding.astro.internal.calc; import java.util.Calendar; import java.util.Map.Entry; import org.apache.commons.lang.time.DateUtils; import org.eclipse.smarthome.binding.astro.internal.model.Position; import org.eclipse.smarthome.binding.astro.internal.model.Radiation; import org.eclipse.smarthome.binding.astro.internal.model.Range; import org.eclipse.smarthome.binding.astro.internal.model.Sun; import org.eclipse.smarthome.binding.astro.internal.model.SunEclipse; import org.eclipse.smarthome.binding.astro.internal.model.SunPhaseName; import org.eclipse.smarthome.binding.astro.internal.util.DateTimeUtils; /** * Calculates the SunPosition (azimuth, elevation) and Sun data. * * @author Gerhard Riegler - Initial contribution * @author Christoph Weitkamp - Introduced UoM * @see based on the calculations of http://www.suncalc.net */ public class SunCalc { private static final double J2000 = 2451545.0; private static final double SC = 1367; // Solar constant in W/m public static final double DEG2RAD = Math.PI / 180; public static final double RAD2DEG = 180. / Math.PI; private static final double M0 = 357.5291 * DEG2RAD; private static final double M1 = 0.98560028 * DEG2RAD; private static final double J0 = 0.0009; private static final double J1 = 0.0053; private static final double J2 = -0.0069; private static final double C1 = 1.9148 * DEG2RAD; private static final double C2 = 0.0200 * DEG2RAD; private static final double C3 = 0.0003 * DEG2RAD; private static final double P = 102.9372 * DEG2RAD; private static final double E = 23.45 * DEG2RAD; private static final double TH0 = 280.1600 * DEG2RAD; private static final double TH1 = 360.9856235 * DEG2RAD; private static final double SUN_ANGLE = -0.83; private static final double SUN_DIAMETER = 0.53 * DEG2RAD; // sun diameter private static final double H0 = SUN_ANGLE * DEG2RAD; private static final double H1 = -6.0 * DEG2RAD; // nautical twilight angle private static final double H2 = -12.0 * DEG2RAD; // astronomical twilight // angle private static final double H3 = -18.0 * DEG2RAD; // darkness angle private static final double MINUTES_PER_DAY = 60 * 24; private static final int CURVE_TIME_INTERVAL = 20; // 20 minutes private static final double JD_ONE_MINUTE_FRACTION = 1.0 / 60 / 24; /** * Calculates the sun position (azimuth and elevation). */ public void setPositionalInfo(Calendar calendar, double latitude, double longitude, Double altitude, Sun sun) { double lw = -longitude * DEG2RAD; double phi = latitude * DEG2RAD; double j = DateTimeUtils.dateToJulianDate(calendar); double m = getSolarMeanAnomaly(j); double c = getEquationOfCenter(m); double lsun = getEclipticLongitude(m, c); double d = getSunDeclination(lsun); double a = getRightAscension(lsun); double th = getSiderealTime(j, lw); double azimuth = getAzimuth(th, a, phi, d) / DEG2RAD; double elevation = getElevation(th, a, phi, d) / DEG2RAD; double shadeLength = getShadeLength(elevation); Position position = sun.getPosition(); position.setAzimuth(azimuth + 180); position.setElevation(elevation); position.setShadeLength(shadeLength); setRadiationInfo(calendar, elevation, altitude, sun); } /** * Calculates sun radiation data. */ public void setRadiationInfo(Calendar calendar, double elevation, Double altitude, Sun sun) { double sinAlpha = Math.sin(DEG2RAD * elevation); int dayOfYear = calendar.get(Calendar.DAY_OF_YEAR); int daysInYear = calendar.getActualMaximum(Calendar.DAY_OF_YEAR); // Direct Solar Radiation (in W/m) at the atmosphere entry // At sunrise/sunset - calculations limits are reached double rOut = (elevation > 3) ? SC * (0.034 * Math.cos(DEG2RAD * (360 * dayOfYear / daysInYear)) + 1) : 0; double altitudeRatio = (altitude != null) ? 1 / Math.pow((1 - (6.5 / 288) * (altitude / 1000.0)), 5.256) : 1; double m = (Math.sqrt(1229 + Math.pow(614 * sinAlpha, 2)) - 614 * sinAlpha) * altitudeRatio; // Direct radiation after atmospheric layer // 0.6 = Coefficient de transmissivit double rDir = rOut * Math.pow(0.6, m) * sinAlpha; // Diffuse Radiation double rDiff = rOut * (0.271 - 0.294 * Math.pow(0.6, m)) * sinAlpha; double rTot = rDir + rDiff; Radiation radiation = sun.getRadiation(); radiation.setDirect(rDir); radiation.setDiffuse(rDiff); radiation.setTotal(rTot); } /** * Returns true, if the sun is up all day (no rise and set). */ private boolean isSunUpAllDay(Calendar calendar, double latitude, double longitude, Double altitude) { Calendar cal = DateTimeUtils.truncateToMidnight(calendar); Sun sun = new Sun(); for (int minutes = 0; minutes <= MINUTES_PER_DAY; minutes += CURVE_TIME_INTERVAL) { setPositionalInfo(cal, latitude, longitude, altitude, sun); if (sun.getPosition().getElevationAsDouble() < SUN_ANGLE) { return false; } cal.add(Calendar.MINUTE, CURVE_TIME_INTERVAL); } return true; } /** * Calculates all sun rise and sets at the specified coordinates. */ public Sun getSunInfo(Calendar calendar, double latitude, double longitude, Double altitude) { return getSunInfo(calendar, latitude, longitude, altitude, false); } private Sun getSunInfo(Calendar calendar, double latitude, double longitude, Double altitude, boolean onlyAstro) { double lw = -longitude * DEG2RAD; double phi = latitude * DEG2RAD; double j = DateTimeUtils.midnightDateToJulianDate(calendar) + 0.5; double n = getJulianCycle(j, lw); double js = getApproxSolarTransit(0, lw, n); double m = getSolarMeanAnomaly(js); double c = getEquationOfCenter(m); double lsun = getEclipticLongitude(m, c); double d = getSunDeclination(lsun); double jtransit = getSolarTransit(js, m, lsun); double w0 = getHourAngle(H0, phi, d); double w1 = getHourAngle(H0 + SUN_DIAMETER, phi, d); double jset = getSunsetJulianDate(w0, m, lsun, lw, n); double jsetstart = getSunsetJulianDate(w1, m, lsun, lw, n); double jrise = getSunriseJulianDate(jtransit, jset); double jriseend = getSunriseJulianDate(jtransit, jsetstart); double w2 = getHourAngle(H1, phi, d); double jnau = getSunsetJulianDate(w2, m, lsun, lw, n); double jciv2 = getSunriseJulianDate(jtransit, jnau); double w3 = getHourAngle(H2, phi, d); double w4 = getHourAngle(H3, phi, d); double jastro = getSunsetJulianDate(w3, m, lsun, lw, n); double jdark = getSunsetJulianDate(w4, m, lsun, lw, n); double jnau2 = getSunriseJulianDate(jtransit, jastro); double jastro2 = getSunriseJulianDate(jtransit, jdark); Sun sun = new Sun(); sun.setAstroDawn(new Range(DateTimeUtils.toCalendar(jastro2), DateTimeUtils.toCalendar(jnau2))); sun.setAstroDusk(new Range(DateTimeUtils.toCalendar(jastro), DateTimeUtils.toCalendar(jdark))); if (onlyAstro) { return sun; } sun.setNoon(new Range(DateTimeUtils.toCalendar(jtransit), DateTimeUtils.toCalendar(jtransit + JD_ONE_MINUTE_FRACTION))); sun.setRise(new Range(DateTimeUtils.toCalendar(jrise), DateTimeUtils.toCalendar(jriseend))); sun.setSet(new Range(DateTimeUtils.toCalendar(jsetstart), DateTimeUtils.toCalendar(jset))); sun.setCivilDawn(new Range(DateTimeUtils.toCalendar(jciv2), DateTimeUtils.toCalendar(jrise))); sun.setCivilDusk(new Range(DateTimeUtils.toCalendar(jset), DateTimeUtils.toCalendar(jnau))); sun.setNauticDawn(new Range(DateTimeUtils.toCalendar(jnau2), DateTimeUtils.toCalendar(jciv2))); sun.setNauticDusk(new Range(DateTimeUtils.toCalendar(jnau), DateTimeUtils.toCalendar(jastro))); boolean isSunUpAllDay = isSunUpAllDay(calendar, latitude, longitude, altitude); // daylight Range daylightRange = new Range(); if (sun.getRise().getStart() == null && sun.getRise().getEnd() == null) { if (isSunUpAllDay) { daylightRange = new Range(DateTimeUtils.truncateToMidnight(calendar), DateTimeUtils.truncateToMidnight(addDays(calendar, 1))); } } else { daylightRange = new Range(sun.getRise().getEnd(), sun.getSet().getStart()); } sun.setDaylight(daylightRange); // morning night Sun sunYesterday = getSunInfo(addDays(calendar, -1), latitude, longitude, altitude, true); Range morningNightRange = null; if (sunYesterday.getAstroDusk().getEnd() != null && DateUtils.isSameDay(sunYesterday.getAstroDusk().getEnd(), calendar)) { morningNightRange = new Range(sunYesterday.getAstroDusk().getEnd(), sun.getAstroDawn().getStart()); } else if (isSunUpAllDay || sun.getAstroDawn().getStart() == null) { morningNightRange = new Range(); } else { morningNightRange = new Range(DateTimeUtils.truncateToMidnight(calendar), sun.getAstroDawn().getStart()); } sun.setMorningNight(morningNightRange); // evening night Range eveningNightRange = null; if (sun.getAstroDusk().getEnd() != null && DateUtils.isSameDay(sun.getAstroDusk().getEnd(), calendar)) { eveningNightRange = new Range(sun.getAstroDusk().getEnd(), DateTimeUtils.truncateToMidnight(addDays(calendar, 1))); } else { eveningNightRange = new Range(); } sun.setEveningNight(eveningNightRange); // night if (isSunUpAllDay) { sun.setNight(new Range()); } else { Sun sunTomorrow = getSunInfo(addDays(calendar, 1), latitude, longitude, altitude, true); sun.setNight(new Range(sun.getAstroDusk().getEnd(), sunTomorrow.getAstroDawn().getStart())); } // eclipse SunEclipse eclipse = sun.getEclipse(); MoonCalc mc = new MoonCalc(); double partial = mc.getEclipse(calendar, MoonCalc.ECLIPSE_TYPE_SUN, j, MoonCalc.ECLIPSE_MODE_PARTIAL); eclipse.setPartial(DateTimeUtils.toCalendar(partial)); double ring = mc.getEclipse(calendar, MoonCalc.ECLIPSE_TYPE_SUN, j, MoonCalc.ECLIPSE_MODE_RING); eclipse.setRing(DateTimeUtils.toCalendar(ring)); double total = mc.getEclipse(calendar, MoonCalc.ECLIPSE_TYPE_SUN, j, MoonCalc.ECLIPSE_MODE_TOTAL); eclipse.setTotal(DateTimeUtils.toCalendar(total)); SunZodiacCalc zodiacCalc = new SunZodiacCalc(); sun.setZodiac(zodiacCalc.getZodiac(calendar)); SeasonCalc seasonCalc = new SeasonCalc(); sun.setSeason(seasonCalc.getSeason(calendar, latitude)); // phase for (Entry<SunPhaseName, Range> rangeEntry : sun.getAllRanges().entrySet()) { SunPhaseName entryPhase = rangeEntry.getKey(); if (rangeEntry.getValue().matches(Calendar.getInstance())) { if (entryPhase == SunPhaseName.MORNING_NIGHT || entryPhase == SunPhaseName.EVENING_NIGHT) { sun.getPhase().setName(SunPhaseName.NIGHT); } else { sun.getPhase().setName(entryPhase); } } } return sun; } /** * Adds the specified days to the calendar. */ private Calendar addDays(Calendar calendar, int days) { Calendar cal = (Calendar) calendar.clone(); cal.add(Calendar.DAY_OF_MONTH, days); return cal; } // all the following methods are translated to java based on the javascript // calculations of http://www.suncalc.net private double getJulianCycle(double j, double lw) { return Math.round(j - J2000 - J0 - lw / (2 * Math.PI)); } private double getApproxSolarTransit(double ht, double lw, double n) { return J2000 + J0 + (ht + lw) / (2 * Math.PI) + n; } private double getSolarMeanAnomaly(double js) { return M0 + M1 * (js - J2000); } private double getEquationOfCenter(double m) { return C1 * Math.sin(m) + C2 * Math.sin(2 * m) + C3 * Math.sin(3 * m); } private double getEclipticLongitude(double m, double c) { return m + P + c + Math.PI; } private double getSolarTransit(double js, double m, double lsun) { return js + (J1 * Math.sin(m)) + (J2 * Math.sin(2 * lsun)); } private double getSunDeclination(double lsun) { return Math.asin(Math.sin(lsun) * Math.sin(E)); } private double getRightAscension(double lsun) { return Math.atan2(Math.sin(lsun) * Math.cos(E), Math.cos(lsun)); } private double getSiderealTime(double j, double lw) { return TH0 + TH1 * (j - J2000) - lw; } private double getAzimuth(double th, double a, double phi, double d) { double h = th - a; return Math.atan2(Math.sin(h), Math.cos(h) * Math.sin(phi) - Math.tan(d) * Math.cos(phi)); } private double getElevation(double th, double a, double phi, double d) { return Math.asin(Math.sin(phi) * Math.sin(d) + Math.cos(phi) * Math.cos(d) * Math.cos(th - a)); } private double getShadeLength(double elevation) { return 1 / Math.tan(elevation * DEG2RAD); } private double getHourAngle(double h, double phi, double d) { return Math.acos((Math.sin(h) - Math.sin(phi) * Math.sin(d)) / (Math.cos(phi) * Math.cos(d))); } private double getSunsetJulianDate(double w0, double m, double Lsun, double lw, double n) { return getSolarTransit(getApproxSolarTransit(w0, lw, n), m, Lsun); } private double getSunriseJulianDate(double jtransit, double jset) { return jtransit - (jset - jtransit); } }