kstars/kstars/ksnumbers.h

   1 /***************************************************************************
   2                           ksnumbers.h  -  description
   3                              -------------------
   4     begin                : Sun Jan 13 2002
   5     copyright            : (C) 2002-2005 by Jason Harris
   6     email                : kstars@30doradus.org
   7     copyright            : (C) 2004-2005 by Pablo de Vicente
   8     email                : p.devicente@wanadoo.es
   9  ***************************************************************************/
  10
  11 /***************************************************************************
  12  *                                                                         *
  13  *   This program is free software; you can redistribute it and/or modify  *
  14  *   it under the terms of the GNU General Public License as published by  *
  15  *   the Free Software Foundation; either version 2 of the License, or     *
  16  *   (at your option) any later version.                                   *
  17  *                                                                         *
  18  ***************************************************************************/
  19
  20 #ifndef KSNUMBERS_H
  21 #define KSNUMBERS_H
  22
  23 #define NUTTERMS 63
  24
  25 #include "dms.h"
  26
  27 /**@class KSNumbers
  28         *
  29         *There are several time-dependent values used in position calculations,
  30         *that are not specific to an object.  This class provides
  31         *storage for these values, and methods for calculating them for a given date.
  32         *The numbers include solar data like the true/mean solar anomalies
  33         *and longitudes, the longitude of the Earth's perihelion, the
  34         *eccentricity of Earth's orbit, the
  35         *constant of aberration, the obliquity of the Ecliptic, the effects of
  36         *Nutation (delta Obliquity and delta Ecliptic longitude),
  37         *the Julian Day/Century/Millenium, and arrays for computing the precession.
  38         *@short Store several time-dependent astronomical quantities.
  39         *@author Jason Harris
  40         *@version 1.0
  41         */
  42
  43 class KSNumbers {
  44 public:
  45         /**Constructor. */
  46         KSNumbers( long double jd );
  47         /**Destructor (empty). */
  48         ~KSNumbers();
  49
  50         /**@return the current Obliquity (the angle of inclination between
  51                 *the celestial equator and the ecliptic)
  52                 */
  53         const dms* obliquity() const { return &Obliquity; }
  54
  55         /**@return the constant of aberration (20.49 arcsec). */
  56         dms constAberr() const { return K; }
  57
  58         /**@return the mean solar anomaly. */
  59         dms sunMeanAnomaly() const { return M; }
  60
  61         /**@return the mean solar longitude. */
  62         dms sunMeanLongitude() const { return L; }
  63
  64         /**@return the true solar anomaly. */
  65         dms sunTrueAnomaly() const { return M0; }
  66
  67         /**@return the true solar longitude. */
  68         dms sunTrueLongitude() const { return L0; }
  69
  70         /**@return the longitude of the Earth's perihelion point. */
  71         dms earthPerihelionLongitude() const { return P; }
  72
  73         /**@return eccentricity of Earth's orbit.*/
  74         double earthEccentricity() const { return e; }
  75
  76         /**@return the change in obliquity due to the nutation of
  77          * Earth's orbit. Value is in degrees */
  78         double dObliq() const { return deltaObliquity; }
  79
  80         /**@return the change in Ecliptic Longitude due to nutation.
  81          * Value is in degrees. */
  82         double dEcLong() const { return deltaEcLong; }
  83
  84         /**@return Julian centuries since J2000*/
  85         double julianCenturies() const { return T; }
  86
  87         /**@return Julian Day*/
  88         long double julianDay() const { return days; }
  89
  90         /**@return Julian Millenia since J2000*/
  91         double julianMillenia() const { return jm; }
  92
  93         /**@return element of P1 precession array at position [i1][i2] */
  94         double p1( int i1, int i2 ) const { return P1[i1][i2]; }
  95
  96         /**@return element of P2 precession array at position [i1][i2] */
  97         double p2( int i1, int i2 ) const { return P2[i1][i2]; }
  98
  99         /**@return element of P1B precession array at position [i1][i2] */
 100         double p1b( int i1, int i2 ) const { return P1B[i1][i2]; }
 101
 102         /**@return element of P2B precession array at position [i1][i2] */
 103         double p2b( int i1, int i2 ) const { return P2B[i1][i2]; }
 104
 105         /**@short update all values for the date given as an argument.
 106                 *@param jd the Julian date for which to compute values
 107                 */
 108         void updateValues( long double jd );
 109
 110         double vEarth(int i) const {return vearth[i];}
 111
 112 private:
 113         dms Obliquity, K, L, L0, LM, M, M0, O, P, D, MM, F;
 114         dms XP, YP, ZP, XB, YB, ZB;
 115         double CX, SX, CY, SY, CZ, SZ;
 116         double CXB, SXB, CYB, SYB, CZB, SZB;
 117         double P1[3][3], P2[3][3], P1B[3][3], P2B[3][3];
 118         double deltaObliquity, deltaEcLong;
 119         double e, T, TB;
 120         long double days;
 121         double jm;
 122         static const int arguments[NUTTERMS][5];
 123         static const int amp[NUTTERMS][4];
 124         double vearth[3];
 125 };
 126
 127 #endif