File indexing completed on 2022-12-06 18:58:43

0001 /*
0002     SPDX-FileCopyrightText: 2002-2005 Jason Harris <kstars@30doradus.org>
0003     SPDX-FileCopyrightText: 2004-2005 Pablo de Vicente <p.devicente@wanadoo.es>
0004 
0005     SPDX-License-Identifier: GPL-2.0-or-later
0006 */
0007 
0008 #pragma once
0009 
0010 #include "cachingdms.h"
0011 
0012 #if __GNUC__ > 5
0013 #pragma GCC diagnostic push
0014 #pragma GCC diagnostic ignored "-Wignored-attributes"
0015 #endif
0016 #if __GNUC__ > 6
0017 #pragma GCC diagnostic ignored "-Wint-in-bool-context"
0018 #endif
0019 #include <Eigen/Core>
0020 #if __GNUC__ > 5
0021 #pragma GCC diagnostic pop
0022 #endif
0023 
0024 #define NUTTERMS 63
0025 
0026 /** @class KSNumbers
0027     *
0028     *There are several time-dependent values used in position calculations,
0029     *that are not specific to an object.  This class provides
0030     *storage for these values, and methods for calculating them for a given date.
0031     *The numbers include solar data like the true/mean solar anomalies
0032     *and longitudes, the longitude of the Earth's perihelion, the
0033     *eccentricity of Earth's orbit, the
0034     *constant of aberration, the obliquity of the Ecliptic, the effects of
0035     *Nutation (delta Obliquity and delta Ecliptic longitude),
0036     *the Julian Day/Century/Millenium, and arrays for computing the precession.
0037     *@short Store several time-dependent astronomical quantities.
0038     *@author Jason Harris
0039     *@version 1.0
0040     */
0041 
0042 class KSNumbers
0043 {
0044   public:
0045     /**
0046      * Constructor.
0047      * @param jd  Julian Day for which the new instance is initialized
0048      */
0049     explicit KSNumbers(long double jd);
0050     ~KSNumbers() = default;
0051 
0052     /**
0053      * @return the current Obliquity (the angle of inclination between
0054      * the celestial equator and the ecliptic)
0055      */
0056     inline const CachingDms *obliquity() const { return &Obliquity; }
0057 
0058     /** @return the constant of aberration (20.49 arcsec). */
0059     inline dms constAberr() const { return K; }
0060 
0061     /** @return the mean solar anomaly. */
0062     inline dms sunMeanAnomaly() const { return M; }
0063 
0064     /** @return the mean solar longitude. */
0065     inline dms sunMeanLongitude() const { return L; }
0066 
0067     /** @return the true solar anomaly. */
0068     inline dms sunTrueAnomaly() const { return M0; }
0069 
0070     /** @return the true solar longitude. */
0071     inline CachingDms sunTrueLongitude() const { return L0; }
0072 
0073     /** @return the longitude of the Earth's perihelion point. */
0074     inline CachingDms earthPerihelionLongitude() const { return P; }
0075 
0076     /** @return eccentricity of Earth's orbit.*/
0077     inline double earthEccentricity() const { return e; }
0078 
0079     /** @return the change in obliquity due to the nutation of
0080          * Earth's orbit. Value is in degrees */
0081     inline double dObliq() const { return deltaObliquity; }
0082 
0083     /** @return the change in Ecliptic Longitude due to nutation.
0084          * Value is in degrees. */
0085     inline double dEcLong() const { return deltaEcLong; }
0086 
0087     /** @return Julian centuries since J2000*/
0088     inline double julianCenturies() const { return T; }
0089 
0090     /** @return Julian Day*/
0091     inline long double julianDay() const { return days; }
0092 
0093     /** @return Julian Millenia since J2000*/
0094     inline double julianMillenia() const { return jm; }
0095 
0096     /** @return element of P1 precession array at position (i1, i2) */
0097     inline double p1(int i1, int i2) const { return P1(i1, i2); }
0098 
0099     /** @return element of P2 precession array at position (i1, i2) */
0100     inline double p2(int i1, int i2) const { return P2(i1, i2); }
0101 
0102     /** @return element of P1B precession array at position (i1, i2) */
0103     inline double p1b(int i1, int i2) const { return P1B(i1, i2); }
0104 
0105     /** @return element of P2B precession array at position (i1, i2) */
0106     inline double p2b(int i1, int i2) const { return P2B(i1, i2); }
0107 
0108     /** @return the precession matrix directly **/
0109     inline const Eigen::Matrix3d &p2() const { return P1; }
0110     inline const Eigen::Matrix3d &p1() const { return P2; }
0111     inline const Eigen::Matrix3d &p1b() const { return P1B; }
0112     inline const Eigen::Matrix3d &p2b() const { return P2B; }
0113 
0114     /**
0115      * @short compute constant values that need to be computed only once per instance of the application
0116      */
0117     void computeConstantValues();
0118 
0119     /**
0120      * @short update all values for the date given as an argument.
0121      * @param jd the Julian date for which to compute values
0122      */
0123     void updateValues(long double jd);
0124 
0125     /**
0126      * @return the JD for which these values hold (i.e. the last updated JD)
0127      */
0128     inline long double getJD() const { return days; }
0129 
0130     inline double vEarth(int i) const { return vearth[i]; }
0131 
0132   private:
0133     CachingDms Obliquity, L0, P;
0134     dms K, L, LM, M, M0, O, D, MM, F;
0135     dms XP, YP, ZP, XB, YB, ZB;
0136     double CX, SX, CY, SY, CZ, SZ;
0137     double CXB, SXB, CYB, SYB, CZB, SZB;
0138     Eigen::Matrix3d P1, P2, P1B, P2B;
0139     double deltaObliquity, deltaEcLong;
0140     double e, T;
0141     long double days; // JD for which the last update was called
0142     double jm;
0143     static const int arguments[NUTTERMS][5];
0144     static const int amp[NUTTERMS][4];
0145     double vearth[3];
0146 };