| 1 | #include "erfa.h"
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| 2 |
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| 3 | int eraPlan94(double date1, double date2, int np, double pv[2][3])
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| 4 | /*
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| 5 | ** - - - - - - - - - -
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| 6 | ** e r a P l a n 9 4
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| 7 | ** - - - - - - - - - -
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| 8 | **
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| 9 | ** Approximate heliocentric position and velocity of a nominated major
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| 10 | ** planet: Mercury, Venus, EMB, Mars, Jupiter, Saturn, Uranus or
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| 11 | ** Neptune (but not the Earth itself).
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| 12 | **
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| 13 | ** Given:
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| 14 | ** date1 double TDB date part A (Note 1)
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| 15 | ** date2 double TDB date part B (Note 1)
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| 16 | ** np int planet (1=Mercury, 2=Venus, 3=EMB, 4=Mars,
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| 17 | ** 5=Jupiter, 6=Saturn, 7=Uranus, 8=Neptune)
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| 18 | **
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| 19 | ** Returned (argument):
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| 20 | ** pv double[2][3] planet p,v (heliocentric, J2000.0, au,au/d)
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| 21 | **
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| 22 | ** Returned (function value):
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| 23 | ** int status: -1 = illegal NP (outside 1-8)
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| 24 | ** 0 = OK
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| 25 | ** +1 = warning: year outside 1000-3000
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| 26 | ** +2 = warning: failed to converge
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| 27 | **
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| 28 | ** Notes:
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| 29 | **
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| 30 | ** 1) The date date1+date2 is in the TDB time scale (in practice TT can
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| 31 | ** be used) and is a Julian Date, apportioned in any convenient way
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| 32 | ** between the two arguments. For example, JD(TDB)=2450123.7 could
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| 33 | ** be expressed in any of these ways, among others:
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| 34 | **
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| 35 | ** date1 date2
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| 36 | **
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| 37 | ** 2450123.7 0.0 (JD method)
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| 38 | ** 2451545.0 -1421.3 (J2000 method)
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| 39 | ** 2400000.5 50123.2 (MJD method)
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| 40 | ** 2450123.5 0.2 (date & time method)
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| 41 | **
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| 42 | ** The JD method is the most natural and convenient to use in cases
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| 43 | ** where the loss of several decimal digits of resolution is
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| 44 | ** acceptable. The J2000 method is best matched to the way the
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| 45 | ** argument is handled internally and will deliver the optimum
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| 46 | ** resolution. The MJD method and the date & time methods are both
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| 47 | ** good compromises between resolution and convenience. The limited
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| 48 | ** accuracy of the present algorithm is such that any of the methods
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| 49 | ** is satisfactory.
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| 50 | **
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| 51 | ** 2) If an np value outside the range 1-8 is supplied, an error status
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| 52 | ** (function value -1) is returned and the pv vector set to zeroes.
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| 53 | **
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| 54 | ** 3) For np=3 the result is for the Earth-Moon Barycenter. To obtain
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| 55 | ** the heliocentric position and velocity of the Earth, use instead
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| 56 | ** the ERFA function eraEpv00.
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| 57 | **
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| 58 | ** 4) On successful return, the array pv contains the following:
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| 59 | **
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| 60 | ** pv[0][0] x }
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| 61 | ** pv[0][1] y } heliocentric position, au
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| 62 | ** pv[0][2] z }
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| 63 | **
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| 64 | ** pv[1][0] xdot }
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| 65 | ** pv[1][1] ydot } heliocentric velocity, au/d
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| 66 | ** pv[1][2] zdot }
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| 67 | **
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| 68 | ** The reference frame is equatorial and is with respect to the
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| 69 | ** mean equator and equinox of epoch J2000.0.
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| 70 | **
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| 71 | ** 5) The algorithm is due to J.L. Simon, P. Bretagnon, J. Chapront,
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| 72 | ** M. Chapront-Touze, G. Francou and J. Laskar (Bureau des
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| 73 | ** Longitudes, Paris, France). From comparisons with JPL
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| 74 | ** ephemeris DE102, they quote the following maximum errors
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| 75 | ** over the interval 1800-2050:
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| 76 | **
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| 77 | ** L (arcsec) B (arcsec) R (km)
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| 78 | **
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| 79 | ** Mercury 4 1 300
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| 80 | ** Venus 5 1 800
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| 81 | ** EMB 6 1 1000
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| 82 | ** Mars 17 1 7700
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| 83 | ** Jupiter 71 5 76000
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| 84 | ** Saturn 81 13 267000
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| 85 | ** Uranus 86 7 712000
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| 86 | ** Neptune 11 1 253000
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| 87 | **
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| 88 | ** Over the interval 1000-3000, they report that the accuracy is no
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| 89 | ** worse than 1.5 times that over 1800-2050. Outside 1000-3000 the
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| 90 | ** accuracy declines.
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| 91 | **
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| 92 | ** Comparisons of the present function with the JPL DE200 ephemeris
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| 93 | ** give the following RMS errors over the interval 1960-2025:
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| 94 | **
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| 95 | ** position (km) velocity (m/s)
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| 96 | **
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| 97 | ** Mercury 334 0.437
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| 98 | ** Venus 1060 0.855
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| 99 | ** EMB 2010 0.815
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| 100 | ** Mars 7690 1.98
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| 101 | ** Jupiter 71700 7.70
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| 102 | ** Saturn 199000 19.4
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| 103 | ** Uranus 564000 16.4
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| 104 | ** Neptune 158000 14.4
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| 105 | **
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| 106 | ** Comparisons against DE200 over the interval 1800-2100 gave the
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| 107 | ** following maximum absolute differences. (The results using
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| 108 | ** DE406 were essentially the same.)
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| 109 | **
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| 110 | ** L (arcsec) B (arcsec) R (km) Rdot (m/s)
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| 111 | **
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| 112 | ** Mercury 7 1 500 0.7
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| 113 | ** Venus 7 1 1100 0.9
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| 114 | ** EMB 9 1 1300 1.0
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| 115 | ** Mars 26 1 9000 2.5
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| 116 | ** Jupiter 78 6 82000 8.2
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| 117 | ** Saturn 87 14 263000 24.6
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| 118 | ** Uranus 86 7 661000 27.4
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| 119 | ** Neptune 11 2 248000 21.4
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| 120 | **
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| 121 | ** 6) The present ERFA re-implementation of the original Simon et al.
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| 122 | ** Fortran code differs from the original in the following respects:
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| 123 | **
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| 124 | ** * C instead of Fortran.
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| 125 | **
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| 126 | ** * The date is supplied in two parts.
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| 127 | **
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| 128 | ** * The result is returned only in equatorial Cartesian form;
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| 129 | ** the ecliptic longitude, latitude and radius vector are not
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| 130 | ** returned.
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| 131 | **
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| 132 | ** * The result is in the J2000.0 equatorial frame, not ecliptic.
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| 133 | **
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| 134 | ** * More is done in-line: there are fewer calls to subroutines.
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| 135 | **
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| 136 | ** * Different error/warning status values are used.
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| 137 | **
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| 138 | ** * A different Kepler's-equation-solver is used (avoiding
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| 139 | ** use of double precision complex).
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| 140 | **
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| 141 | ** * Polynomials in t are nested to minimize rounding errors.
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| 142 | **
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| 143 | ** * Explicit double constants are used to avoid mixed-mode
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| 144 | ** expressions.
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| 145 | **
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| 146 | ** None of the above changes affects the result significantly.
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| 147 | **
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| 148 | ** 7) The returned status indicates the most serious condition
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| 149 | ** encountered during execution of the function. Illegal np is
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| 150 | ** considered the most serious, overriding failure to converge,
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| 151 | ** which in turn takes precedence over the remote date warning.
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| 152 | **
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| 153 | ** Called:
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| 154 | ** eraAnp normalize angle into range 0 to 2pi
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| 155 | **
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| 156 | ** Reference: Simon, J.L, Bretagnon, P., Chapront, J.,
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| 157 | ** Chapront-Touze, M., Francou, G., and Laskar, J.,
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| 158 | ** Astron. Astrophys. 282, 663 (1994).
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| 159 | **
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| 160 | ** Copyright (C) 2013-2017, NumFOCUS Foundation.
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| 161 | ** Derived, with permission, from the SOFA library. See notes at end of file.
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| 162 | */
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| 163 | {
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| 164 | /* Gaussian constant */
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| 165 | static const double GK = 0.017202098950;
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| 166 |
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| 167 | /* Sin and cos of J2000.0 mean obliquity (IAU 1976) */
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| 168 | static const double SINEPS = 0.3977771559319137;
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| 169 | static const double COSEPS = 0.9174820620691818;
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| 170 |
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| 171 | /* Maximum number of iterations allowed to solve Kepler's equation */
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| 172 | static const int KMAX = 10;
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| 173 |
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| 174 | int jstat, i, k;
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| 175 | double t, da, dl, de, dp, di, dom, dmu, arga, argl, am,
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| 176 | ae, dae, ae2, at, r, v, si2, xq, xp, tl, xsw,
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| 177 | xcw, xm2, xf, ci2, xms, xmc, xpxq2, x, y, z;
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| 178 |
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| 179 | /* Planetary inverse masses */
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| 180 | static const double amas[] = { 6023600.0, /* Mercury */
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| 181 | 408523.5, /* Venus */
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| 182 | 328900.5, /* EMB */
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| 183 | 3098710.0, /* Mars */
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| 184 | 1047.355, /* Jupiter */
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| 185 | 3498.5, /* Saturn */
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| 186 | 22869.0, /* Uranus */
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| 187 | 19314.0 }; /* Neptune */
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| 188 |
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| 189 | /*
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| 190 | ** Tables giving the mean Keplerian elements, limited to t^2 terms:
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| 191 | **
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| 192 | ** a semi-major axis (au)
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| 193 | ** dlm mean longitude (degree and arcsecond)
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| 194 | ** e eccentricity
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| 195 | ** pi longitude of the perihelion (degree and arcsecond)
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| 196 | ** dinc inclination (degree and arcsecond)
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| 197 | ** omega longitude of the ascending node (degree and arcsecond)
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| 198 | */
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| 199 |
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| 200 | static const double a[][3] = {
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| 201 | { 0.3870983098, 0.0, 0.0 }, /* Mercury */
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| 202 | { 0.7233298200, 0.0, 0.0 }, /* Venus */
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| 203 | { 1.0000010178, 0.0, 0.0 }, /* EMB */
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| 204 | { 1.5236793419, 3e-10, 0.0 }, /* Mars */
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| 205 | { 5.2026032092, 19132e-10, -39e-10 }, /* Jupiter */
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| 206 | { 9.5549091915, -0.0000213896, 444e-10 }, /* Saturn */
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| 207 | { 19.2184460618, -3716e-10, 979e-10 }, /* Uranus */
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| 208 | { 30.1103868694, -16635e-10, 686e-10 } /* Neptune */
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| 209 | };
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| 210 |
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| 211 | static const double dlm[][3] = {
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| 212 | { 252.25090552, 5381016286.88982, -1.92789 },
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| 213 | { 181.97980085, 2106641364.33548, 0.59381 },
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| 214 | { 100.46645683, 1295977422.83429, -2.04411 },
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| 215 | { 355.43299958, 689050774.93988, 0.94264 },
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| 216 | { 34.35151874, 109256603.77991, -30.60378 },
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| 217 | { 50.07744430, 43996098.55732, 75.61614 },
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| 218 | { 314.05500511, 15424811.93933, -1.75083 },
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| 219 | { 304.34866548, 7865503.20744, 0.21103 }
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| 220 | };
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| 221 |
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| 222 | static const double e[][3] = {
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| 223 | { 0.2056317526, 0.0002040653, -28349e-10 },
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| 224 | { 0.0067719164, -0.0004776521, 98127e-10 },
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| 225 | { 0.0167086342, -0.0004203654, -0.0000126734 },
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| 226 | { 0.0934006477, 0.0009048438, -80641e-10 },
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| 227 | { 0.0484979255, 0.0016322542, -0.0000471366 },
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| 228 | { 0.0555481426, -0.0034664062, -0.0000643639 },
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| 229 | { 0.0463812221, -0.0002729293, 0.0000078913 },
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| 230 | { 0.0094557470, 0.0000603263, 0.0 }
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| 231 | };
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| 232 |
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| 233 | static const double pi[][3] = {
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| 234 | { 77.45611904, 5719.11590, -4.83016 },
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| 235 | { 131.56370300, 175.48640, -498.48184 },
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| 236 | { 102.93734808, 11612.35290, 53.27577 },
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| 237 | { 336.06023395, 15980.45908, -62.32800 },
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| 238 | { 14.33120687, 7758.75163, 259.95938 },
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| 239 | { 93.05723748, 20395.49439, 190.25952 },
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| 240 | { 173.00529106, 3215.56238, -34.09288 },
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| 241 | { 48.12027554, 1050.71912, 27.39717 }
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| 242 | };
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| 243 |
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| 244 | static const double dinc[][3] = {
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| 245 | { 7.00498625, -214.25629, 0.28977 },
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| 246 | { 3.39466189, -30.84437, -11.67836 },
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| 247 | { 0.0, 469.97289, -3.35053 },
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| 248 | { 1.84972648, -293.31722, -8.11830 },
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| 249 | { 1.30326698, -71.55890, 11.95297 },
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| 250 | { 2.48887878, 91.85195, -17.66225 },
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| 251 | { 0.77319689, -60.72723, 1.25759 },
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| 252 | { 1.76995259, 8.12333, 0.08135 }
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| 253 | };
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| 254 |
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| 255 | static const double omega[][3] = {
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| 256 | { 48.33089304, -4515.21727, -31.79892 },
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| 257 | { 76.67992019, -10008.48154, -51.32614 },
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| 258 | { 174.87317577, -8679.27034, 15.34191 },
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| 259 | { 49.55809321, -10620.90088, -230.57416 },
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| 260 | { 100.46440702, 6362.03561, 326.52178 },
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| 261 | { 113.66550252, -9240.19942, -66.23743 },
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| 262 | { 74.00595701, 2669.15033, 145.93964 },
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| 263 | { 131.78405702, -221.94322, -0.78728 }
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| 264 | };
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| 265 |
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| 266 | /* Tables for trigonometric terms to be added to the mean elements of */
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| 267 | /* the semi-major axes */
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| 268 |
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| 269 | static const double kp[][9] = {
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| 270 | { 69613, 75645, 88306, 59899, 15746, 71087, 142173, 3086, 0 },
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| 271 | { 21863, 32794, 26934, 10931, 26250, 43725, 53867, 28939, 0 },
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| 272 | { 16002, 21863, 32004, 10931, 14529, 16368, 15318, 32794, 0 },
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| 273 | { 6345, 7818, 15636, 7077, 8184, 14163, 1107, 4872, 0 },
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| 274 | { 1760, 1454, 1167, 880, 287, 2640, 19, 2047, 1454 },
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| 275 | { 574, 0, 880, 287, 19, 1760, 1167, 306, 574 },
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| 276 | { 204, 0, 177, 1265, 4, 385, 200, 208, 204 },
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| 277 | { 0, 102, 106, 4, 98, 1367, 487, 204, 0 }
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| 278 | };
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| 279 |
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| 280 | static const double ca[][9] = {
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| 281 | { 4, -13, 11, -9, -9, -3, -1, 4, 0 },
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| 282 | { -156, 59, -42, 6, 19, -20, -10, -12, 0 },
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| 283 | { 64, -152, 62, -8, 32, -41, 19, -11, 0 },
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| 284 | { 124, 621, -145, 208, 54, -57, 30, 15, 0 },
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| 285 | { -23437, -2634, 6601, 6259, -1507,-1821, 2620, -2115, -1489 },
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| 286 | { 62911,-119919, 79336,17814,-24241,12068, 8306, -4893, 8902 },
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| 287 | { 389061,-262125,-44088, 8387,-22976,-2093, -615, -9720, 6633 },
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| 288 | { -412235,-157046,-31430,37817, -9740, -13, -7449, 9644, 0 }
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| 289 | };
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| 290 |
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| 291 | static const double sa[][9] = {
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| 292 | { -29, -1, 9, 6, -6, 5, 4, 0, 0 },
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| 293 | { -48, -125, -26, -37, 18, -13, -20, -2, 0 },
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| 294 | { -150, -46, 68, 54, 14, 24, -28, 22, 0 },
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| 295 | { -621, 532, -694, -20, 192, -94, 71, -73, 0 },
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| 296 | { -14614,-19828, -5869, 1881, -4372, -2255, 782, 930, 913 },
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| 297 | { 139737, 0, 24667, 51123, -5102, 7429, -4095, -1976, -9566 },
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| 298 | { -138081, 0, 37205,-49039,-41901,-33872,-27037,-12474, 18797 },
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| 299 | { 0, 28492,133236, 69654, 52322,-49577,-26430, -3593, 0 }
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| 300 | };
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| 301 |
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| 302 | /* Tables giving the trigonometric terms to be added to the mean */
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| 303 | /* elements of the mean longitudes */
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| 304 |
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| 305 | static const double kq[][10] = {
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| 306 | { 3086,15746,69613,59899,75645,88306, 12661, 2658, 0, 0 },
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| 307 | { 21863,32794,10931, 73, 4387,26934, 1473, 2157, 0, 0 },
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| 308 | { 10,16002,21863,10931, 1473,32004, 4387, 73, 0, 0 },
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| 309 | { 10, 6345, 7818, 1107,15636, 7077, 8184, 532, 10, 0 },
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| 310 | { 19, 1760, 1454, 287, 1167, 880, 574, 2640, 19, 1454 },
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| 311 | { 19, 574, 287, 306, 1760, 12, 31, 38, 19, 574 },
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| 312 | { 4, 204, 177, 8, 31, 200, 1265, 102, 4, 204 },
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| 313 | { 4, 102, 106, 8, 98, 1367, 487, 204, 4, 102 }
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| 314 | };
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| 315 |
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| 316 | static const double cl[][10] = {
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| 317 | { 21, -95, -157, 41, -5, 42, 23, 30, 0, 0 },
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| 318 | { -160, -313, -235, 60, -74, -76, -27, 34, 0, 0 },
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| 319 | { -325, -322, -79, 232, -52, 97, 55, -41, 0, 0 },
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| 320 | { 2268, -979, 802, 602, -668, -33, 345, 201, -55, 0 },
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| 321 | { 7610, -4997,-7689,-5841,-2617, 1115,-748,-607, 6074, 354 },
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| 322 | { -18549, 30125,20012, -730, 824, 23,1289,-352, -14767, -2062 },
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| 323 | { -135245,-14594, 4197,-4030,-5630,-2898,2540,-306, 2939, 1986 },
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| 324 | { 89948, 2103, 8963, 2695, 3682, 1648, 866,-154, -1963, -283 }
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| 325 | };
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| 326 |
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| 327 | static const double sl[][10] = {
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| 328 | { -342, 136, -23, 62, 66, -52, -33, 17, 0, 0 },
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| 329 | { 524, -149, -35, 117, 151, 122, -71, -62, 0, 0 },
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| 330 | { -105, -137, 258, 35, -116, -88,-112, -80, 0, 0 },
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| 331 | { 854, -205, -936, -240, 140, -341, -97, -232, 536, 0 },
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| 332 | { -56980, 8016, 1012, 1448,-3024,-3710, 318, 503, 3767, 577 },
|
|---|
| 333 | { 138606,-13478,-4964, 1441,-1319,-1482, 427, 1236, -9167, -1918 },
|
|---|
| 334 | { 71234,-41116, 5334,-4935,-1848, 66, 434, -1748, 3780, -701 },
|
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| 335 | { -47645, 11647, 2166, 3194, 679, 0,-244, -419, -2531, 48 }
|
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| 336 | };
|
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| 337 |
|
|---|
| 338 | /*--------------------------------------------------------------------*/
|
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| 339 |
|
|---|
| 340 | /* Validate the planet number. */
|
|---|
| 341 | if ((np < 1) || (np > 8)) {
|
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| 342 | jstat = -1;
|
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| 343 |
|
|---|
| 344 | /* Reset the result in case of failure. */
|
|---|
| 345 | for (k = 0; k < 2; k++) {
|
|---|
| 346 | for (i = 0; i < 3; i++) {
|
|---|
| 347 | pv[k][i] = 0.0;
|
|---|
| 348 | }
|
|---|
| 349 | }
|
|---|
| 350 |
|
|---|
| 351 | } else {
|
|---|
| 352 |
|
|---|
| 353 | /* Decrement the planet number to start at zero. */
|
|---|
| 354 | np--;
|
|---|
| 355 |
|
|---|
| 356 | /* Time: Julian millennia since J2000.0. */
|
|---|
| 357 | t = ((date1 - ERFA_DJ00) + date2) / ERFA_DJM;
|
|---|
| 358 |
|
|---|
| 359 | /* OK status unless remote date. */
|
|---|
| 360 | jstat = fabs(t) <= 1.0 ? 0 : 1;
|
|---|
| 361 |
|
|---|
| 362 | /* Compute the mean elements. */
|
|---|
| 363 | da = a[np][0] +
|
|---|
| 364 | (a[np][1] +
|
|---|
| 365 | a[np][2] * t) * t;
|
|---|
| 366 | dl = (3600.0 * dlm[np][0] +
|
|---|
| 367 | (dlm[np][1] +
|
|---|
| 368 | dlm[np][2] * t) * t) * ERFA_DAS2R;
|
|---|
| 369 | de = e[np][0] +
|
|---|
| 370 | ( e[np][1] +
|
|---|
| 371 | e[np][2] * t) * t;
|
|---|
| 372 | dp = eraAnpm((3600.0 * pi[np][0] +
|
|---|
| 373 | (pi[np][1] +
|
|---|
| 374 | pi[np][2] * t) * t) * ERFA_DAS2R);
|
|---|
| 375 | di = (3600.0 * dinc[np][0] +
|
|---|
| 376 | (dinc[np][1] +
|
|---|
| 377 | dinc[np][2] * t) * t) * ERFA_DAS2R;
|
|---|
| 378 | dom = eraAnpm((3600.0 * omega[np][0] +
|
|---|
| 379 | (omega[np][1] +
|
|---|
| 380 | omega[np][2] * t) * t) * ERFA_DAS2R);
|
|---|
| 381 |
|
|---|
| 382 | /* Apply the trigonometric terms. */
|
|---|
| 383 | dmu = 0.35953620 * t;
|
|---|
| 384 | for (k = 0; k < 8; k++) {
|
|---|
| 385 | arga = kp[np][k] * dmu;
|
|---|
| 386 | argl = kq[np][k] * dmu;
|
|---|
| 387 | da += (ca[np][k] * cos(arga) +
|
|---|
| 388 | sa[np][k] * sin(arga)) * 1e-7;
|
|---|
| 389 | dl += (cl[np][k] * cos(argl) +
|
|---|
| 390 | sl[np][k] * sin(argl)) * 1e-7;
|
|---|
| 391 | }
|
|---|
| 392 | arga = kp[np][8] * dmu;
|
|---|
| 393 | da += t * (ca[np][8] * cos(arga) +
|
|---|
| 394 | sa[np][8] * sin(arga)) * 1e-7;
|
|---|
| 395 | for (k = 8; k < 10; k++) {
|
|---|
| 396 | argl = kq[np][k] * dmu;
|
|---|
| 397 | dl += t * (cl[np][k] * cos(argl) +
|
|---|
| 398 | sl[np][k] * sin(argl)) * 1e-7;
|
|---|
| 399 | }
|
|---|
| 400 | dl = fmod(dl, ERFA_D2PI);
|
|---|
| 401 |
|
|---|
| 402 | /* Iterative soln. of Kepler's equation to get eccentric anomaly. */
|
|---|
| 403 | am = dl - dp;
|
|---|
| 404 | ae = am + de * sin(am);
|
|---|
| 405 | k = 0;
|
|---|
| 406 | dae = 1.0;
|
|---|
| 407 | while (k < KMAX && fabs(dae) > 1e-12) {
|
|---|
| 408 | dae = (am - ae + de * sin(ae)) / (1.0 - de * cos(ae));
|
|---|
| 409 | ae += dae;
|
|---|
| 410 | k++;
|
|---|
| 411 | if (k == KMAX-1) jstat = 2;
|
|---|
| 412 | }
|
|---|
| 413 |
|
|---|
| 414 | /* True anomaly. */
|
|---|
| 415 | ae2 = ae / 2.0;
|
|---|
| 416 | at = 2.0 * atan2(sqrt((1.0 + de) / (1.0 - de)) * sin(ae2),
|
|---|
| 417 | cos(ae2));
|
|---|
| 418 |
|
|---|
| 419 | /* Distance (au) and speed (radians per day). */
|
|---|
| 420 | r = da * (1.0 - de * cos(ae));
|
|---|
| 421 | v = GK * sqrt((1.0 + 1.0 / amas[np]) / (da * da * da));
|
|---|
| 422 |
|
|---|
| 423 | si2 = sin(di / 2.0);
|
|---|
| 424 | xq = si2 * cos(dom);
|
|---|
| 425 | xp = si2 * sin(dom);
|
|---|
| 426 | tl = at + dp;
|
|---|
| 427 | xsw = sin(tl);
|
|---|
| 428 | xcw = cos(tl);
|
|---|
| 429 | xm2 = 2.0 * (xp * xcw - xq * xsw);
|
|---|
| 430 | xf = da / sqrt(1 - de * de);
|
|---|
| 431 | ci2 = cos(di / 2.0);
|
|---|
| 432 | xms = (de * sin(dp) + xsw) * xf;
|
|---|
| 433 | xmc = (de * cos(dp) + xcw) * xf;
|
|---|
| 434 | xpxq2 = 2 * xp * xq;
|
|---|
| 435 |
|
|---|
| 436 | /* Position (J2000.0 ecliptic x,y,z in au). */
|
|---|
| 437 | x = r * (xcw - xm2 * xp);
|
|---|
| 438 | y = r * (xsw + xm2 * xq);
|
|---|
| 439 | z = r * (-xm2 * ci2);
|
|---|
| 440 |
|
|---|
| 441 | /* Rotate to equatorial. */
|
|---|
| 442 | pv[0][0] = x;
|
|---|
| 443 | pv[0][1] = y * COSEPS - z * SINEPS;
|
|---|
| 444 | pv[0][2] = y * SINEPS + z * COSEPS;
|
|---|
| 445 |
|
|---|
| 446 | /* Velocity (J2000.0 ecliptic xdot,ydot,zdot in au/d). */
|
|---|
| 447 | x = v * (( -1.0 + 2.0 * xp * xp) * xms + xpxq2 * xmc);
|
|---|
| 448 | y = v * (( 1.0 - 2.0 * xq * xq) * xmc - xpxq2 * xms);
|
|---|
| 449 | z = v * (2.0 * ci2 * (xp * xms + xq * xmc));
|
|---|
| 450 |
|
|---|
| 451 | /* Rotate to equatorial. */
|
|---|
| 452 | pv[1][0] = x;
|
|---|
| 453 | pv[1][1] = y * COSEPS - z * SINEPS;
|
|---|
| 454 | pv[1][2] = y * SINEPS + z * COSEPS;
|
|---|
| 455 |
|
|---|
| 456 | }
|
|---|
| 457 |
|
|---|
| 458 | /* Return the status. */
|
|---|
| 459 | return jstat;
|
|---|
| 460 |
|
|---|
| 461 | }
|
|---|
| 462 | /*----------------------------------------------------------------------
|
|---|
| 463 | **
|
|---|
| 464 | **
|
|---|
| 465 | ** Copyright (C) 2013-2017, NumFOCUS Foundation.
|
|---|
| 466 | ** All rights reserved.
|
|---|
| 467 | **
|
|---|
| 468 | ** This library is derived, with permission, from the International
|
|---|
| 469 | ** Astronomical Union's "Standards of Fundamental Astronomy" library,
|
|---|
| 470 | ** available from http://www.iausofa.org.
|
|---|
| 471 | **
|
|---|
| 472 | ** The ERFA version is intended to retain identical functionality to
|
|---|
| 473 | ** the SOFA library, but made distinct through different function and
|
|---|
| 474 | ** file names, as set out in the SOFA license conditions. The SOFA
|
|---|
| 475 | ** original has a role as a reference standard for the IAU and IERS,
|
|---|
| 476 | ** and consequently redistribution is permitted only in its unaltered
|
|---|
| 477 | ** state. The ERFA version is not subject to this restriction and
|
|---|
| 478 | ** therefore can be included in distributions which do not support the
|
|---|
| 479 | ** concept of "read only" software.
|
|---|
| 480 | **
|
|---|
| 481 | ** Although the intent is to replicate the SOFA API (other than
|
|---|
| 482 | ** replacement of prefix names) and results (with the exception of
|
|---|
| 483 | ** bugs; any that are discovered will be fixed), SOFA is not
|
|---|
| 484 | ** responsible for any errors found in this version of the library.
|
|---|
| 485 | **
|
|---|
| 486 | ** If you wish to acknowledge the SOFA heritage, please acknowledge
|
|---|
| 487 | ** that you are using a library derived from SOFA, rather than SOFA
|
|---|
| 488 | ** itself.
|
|---|
| 489 | **
|
|---|
| 490 | **
|
|---|
| 491 | ** TERMS AND CONDITIONS
|
|---|
| 492 | **
|
|---|
| 493 | ** Redistribution and use in source and binary forms, with or without
|
|---|
| 494 | ** modification, are permitted provided that the following conditions
|
|---|
| 495 | ** are met:
|
|---|
| 496 | **
|
|---|
| 497 | ** 1 Redistributions of source code must retain the above copyright
|
|---|
| 498 | ** notice, this list of conditions and the following disclaimer.
|
|---|
| 499 | **
|
|---|
| 500 | ** 2 Redistributions in binary form must reproduce the above copyright
|
|---|
| 501 | ** notice, this list of conditions and the following disclaimer in
|
|---|
| 502 | ** the documentation and/or other materials provided with the
|
|---|
| 503 | ** distribution.
|
|---|
| 504 | **
|
|---|
| 505 | ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
|
|---|
| 506 | ** the International Astronomical Union nor the names of its
|
|---|
| 507 | ** contributors may be used to endorse or promote products derived
|
|---|
| 508 | ** from this software without specific prior written permission.
|
|---|
| 509 | **
|
|---|
| 510 | ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|---|
| 511 | ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|---|
| 512 | ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|---|
| 513 | ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|---|
| 514 | ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|---|
| 515 | ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|---|
| 516 | ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|---|
| 517 | ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|---|
| 518 | ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|---|
| 519 | ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|---|
| 520 | ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|---|
| 521 | ** POSSIBILITY OF SUCH DAMAGE.
|
|---|
| 522 | **
|
|---|
| 523 | */
|
|---|