SUBROUTINE iau_PLAN94 ( DATE1, DATE2, NP, PV, J ) *+ * - - - - - - - - - - - * i a u _ P L A N 9 4 * - - - - - - - - - - - * * This routine is part of the International Astronomical Union's * SOFA (Standards of Fundamental Astronomy) software collection. * * Status: support routine. * * Approximate heliocentric position and velocity of a nominated major * planet: Mercury, Venus, EMB, Mars, Jupiter, Saturn, Uranus or * Neptune (but not the Earth itself). * * Given: * DATE1 d TDB date part A (Note 1) * DATE2 d TDB date part B (Note 1) * NP i planet (1=Mercury, 2=Venus, 3=EMB ... 8=Neptune) * * Returned: * PV d(3,2) planet pos,vel (heliocentric, J2000, AU, AU/d) * J i status: -1 = illegal NP (outside 1-8) * 0 = OK * +1 = warning: date outside 1000-3000 AD * +2 = warning: solution failed to converge * * Notes * * 1) The date DATE1+DATE2 is in the TDB timescale and is a Julian Date, * apportioned in any convenient way between the two arguments. For * example, JD(TDB)=2450123.7 could be expressed in any of these * ways, among others: * * DATE1 DATE2 * * 2450123.7D0 0D0 (JD method) * 2451545D0 -1421.3D0 (J2000 method) * 2400000.5D0 50123.2D0 (MJD method) * 2450123.5D0 0.2D0 (date & time method) * * The JD method is the most natural and convenient to use in * cases where the loss of several decimal digits of resolution * is acceptable. The J2000 method is best matched to the way * the argument is handled internally and will deliver the * optimum resolution. The MJD method and the date & time methods * are both good compromises between resolution and convenience. * The limited accuracy of the present algorithm is such that any * of the methods is satisfactory. * * 2) If an NP value outside the range 1-8 is supplied, an error * status (J = -1) is returned and the PV vector set to zeroes. * * 3) For NP=3 the result is for the Earth-Moon Barycenter. To * obtain the heliocentric position and velocity of the Earth, * use instead the SOFA routine iau_EPV00. * * 4) On successful return, the array PV contains the following: * * PV(1,1) x } * PV(2,1) y } heliocentric position, AU * PV(3,1) z } * * PV(1,2) xdot } * PV(2,2) ydot } heliocentric velocity, AU/d * PV(3,2) zdot } * * The reference frame is equatorial and is with respect to the * mean equator and equinox of epoch J2000. * * 5) The algorithm is due to J.L. Simon, P. Bretagnon, J. Chapront, * M. Chapront-Touze, G. Francou and J. Laskar (Bureau des * Longitudes, Paris, France). From comparisons with JPL * ephemeris DE102, they quote the following maximum errors * over the interval 1800-2050: * * L (arcsec) B (arcsec) R (km) * * Mercury 4 1 300 * Venus 5 1 800 * EMB 6 1 1000 * Mars 17 1 7700 * Jupiter 71 5 76000 * Saturn 81 13 267000 * Uranus 86 7 712000 * Neptune 11 1 253000 * * Over the interval 1000-3000, they report that the accuracy is no * worse than 1.5 times that over 1800-2050. Outside 1000-3000 the * accuracy declines. * * Comparisons of the present routine with the JPL DE200 ephemeris * give the following RMS errors over the interval 1960-2025: * * position (km) velocity (m/s) * * Mercury 334 0.437 * Venus 1060 0.855 * EMB 2010 0.815 * Mars 7690 1.98 * Jupiter 71700 7.70 * Saturn 199000 19.4 * Uranus 564000 16.4 * Neptune 158000 14.4 * * Comparisons against DE200 over the interval 1800-2100 gave the * following maximum absolute differences. (The results using * DE406 were essentially the same.) * * L (arcsec) B (arcsec) R (km) Rdot (m/s) * * Mercury 7 1 500 0.7 * Venus 7 1 1100 0.9 * EMB 9 1 1300 1.0 * Mars 26 1 9000 2.5 * Jupiter 78 6 82000 8.2 * Saturn 87 14 263000 24.6 * Uranus 86 7 661000 27.4 * Neptune 11 2 248000 21.4 * * 6) The present SOFA re-implementation of the original Simon et al. * Fortran code differs from the original in the following respects: * * * The date is supplied in two parts. * * * The result is returned only in equatorial Cartesian form; * the ecliptic longitude, latitude and radius vector are not * returned. * * * The result is in the J2000 equatorial frame, not ecliptic. * * * More is done in-line: there are fewer calls to other * routines. * * * Different error/warning status values are used. * * * A different Kepler's-equation-solver is used (avoiding * use of COMPLEX*16). * * * Polynomials in T are nested to minimize rounding errors. * * * Explicit double-precision constants are used to avoid * mixed-mode expressions. * * * There are other, cosmetic, changes to comply with SOFA * style conventions. * * None of the above changes affects the result significantly. * * 7) The returned status, J, indicates the most serious condition * encountered during execution of the routine. Illegal NP is * considered the most serious, overriding failure to converge, * which in turn takes precedence over the remote epoch warning. * * Called: * iau_ANP normalize angle into range 0 to 2pi * * Reference: Simon, J.L, Bretagnon, P., Chapront, J., * Chapront-Touze, M., Francou, G., and Laskar, J., * Astron. Astrophys. 282, 663 (1994). * * This revision: 2007 September 14 * * Copyright (C) 2008 IAU SOFA Review Board. See notes at end. * *----------------------------------------------------------------------- IMPLICIT NONE DOUBLE PRECISION DATE1, DATE2 INTEGER NP DOUBLE PRECISION PV(3,2) INTEGER J * Maximum number of iterations allowed to solve Kepler's equation INTEGER KMAX PARAMETER ( KMAX = 10 ) * 2Pi DOUBLE PRECISION D2PI PARAMETER ( D2PI = 6.283185307179586476925287D0 ) * Arcseconds to radians DOUBLE PRECISION DAS2R PARAMETER ( DAS2R = 4.848136811095359935899141D-6 ) * Reference epoch (J2000), JD DOUBLE PRECISION DJ0 PARAMETER ( DJ0 = 2451545D0 ) * Days per Julian millennium DOUBLE PRECISION DJM PARAMETER ( DJM = 365250D0 ) * Sin and cos of J2000 mean obliquity (IAU 1976) DOUBLE PRECISION SINEPS, COSEPS PARAMETER ( SINEPS = 0.3977771559319137D0, : COSEPS = 0.9174820620691818D0 ) * Gaussian constant DOUBLE PRECISION GK PARAMETER ( GK = 0.017202098950D0 ) INTEGER JSTAT, I, K DOUBLE PRECISION AMAS(8), A(3,8), DLM(3,8), E(3,8), : PI(3,8), DINC(3,8), OMEGA(3,8), : KP(9,8), CA(9,8), SA(9,8), : KQ(10,8), CL(10,8), SL(10,8), : T, DA, DL, DE, DP, DI, DOM, DMU, ARGA, ARGL, AM, : AE, DAE, AE2, AT, R, V, SI2, XQ, XP, TL, XSW, : XCW, XM2, XF, CI2, XMS, XMC, XPXQ2, X, Y, Z DOUBLE PRECISION iau_ANPM * Planetary inverse masses DATA AMAS / 6023600D0, 408523.5D0, 328900.5D0, 3098710D0, : 1047.355D0, 3498.5D0, 22869D0, 19314D0 / * * Tables giving the mean Keplerian elements, limited to T**2 terms: * * A semi-major axis (AU) * DLM mean longitude (degree and arcsecond) * E eccentricity * PI longitude of the perihelion (degree and arcsecond) * DINC inclination (degree and arcsecond) * OMEGA longitude of the ascending node (degree and arcsecond) * DATA A / : 0.3870983098D0, 0D0, 0D0, : 0.7233298200D0, 0D0, 0D0, : 1.0000010178D0, 0D0, 0D0, : 1.5236793419D0, 3D-10, 0D0, : 5.2026032092D0, 19132D-10, -39D-10, : 9.5549091915D0, -0.0000213896D0, 444D-10, : 19.2184460618D0, -3716D-10, 979D-10, : 30.1103868694D0, -16635D-10, 686D-10 / * DATA DLM / : 252.25090552D0, 5381016286.88982D0, -1.92789D0, : 181.97980085D0, 2106641364.33548D0, 0.59381D0, : 100.46645683D0, 1295977422.83429D0, -2.04411D0, : 355.43299958D0, 689050774.93988D0, 0.94264D0, : 34.35151874D0, 109256603.77991D0, -30.60378D0, : 50.07744430D0, 43996098.55732D0, 75.61614D0, : 314.05500511D0, 15424811.93933D0, -1.75083D0, : 304.34866548D0, 7865503.20744D0, 0.21103D0 / * DATA E / : 0.2056317526D0, 0.0002040653D0, -28349D-10, : 0.0067719164D0, -0.0004776521D0, 98127D-10, : 0.0167086342D0, -0.0004203654D0, -0.0000126734D0, : 0.0934006477D0, 0.0009048438D0, -80641D-10, : 0.0484979255D0, 0.0016322542D0, -0.0000471366D0, : 0.0555481426D0, -0.0034664062D0, -0.0000643639D0, : 0.0463812221D0, -0.0002729293D0, 0.0000078913D0, : 0.0094557470D0, 0.0000603263D0, 0D0 / * DATA PI / : 77.45611904D0, 5719.11590D0, -4.83016D0, : 131.56370300D0, 175.48640D0, -498.48184D0, : 102.93734808D0, 11612.35290D0, 53.27577D0, : 336.06023395D0, 15980.45908D0, -62.32800D0, : 14.33120687D0, 7758.75163D0, 259.95938D0, : 93.05723748D0, 20395.49439D0, 190.25952D0, : 173.00529106D0, 3215.56238D0, -34.09288D0, : 48.12027554D0, 1050.71912D0, 27.39717D0 / * DATA DINC / : 7.00498625D0, -214.25629D0, 0.28977D0, : 3.39466189D0, -30.84437D0, -11.67836D0, : 0D0, 469.97289D0, -3.35053D0, : 1.84972648D0, -293.31722D0, -8.11830D0, : 1.30326698D0, -71.55890D0, 11.95297D0, : 2.48887878D0, 91.85195D0, -17.66225D0, : 0.77319689D0, -60.72723D0, 1.25759D0, : 1.76995259D0, 8.12333D0, 0.08135D0 / * DATA OMEGA / : 48.33089304D0, -4515.21727D0, -31.79892D0, : 76.67992019D0, -10008.48154D0, -51.32614D0, : 174.87317577D0, -8679.27034D0, 15.34191D0, : 49.55809321D0, -10620.90088D0, -230.57416D0, : 100.46440702D0, 6362.03561D0, 326.52178D0, : 113.66550252D0, -9240.19942D0, -66.23743D0, : 74.00595701D0, 2669.15033D0, 145.93964D0, : 131.78405702D0, -221.94322D0, -0.78728D0 / * * Tables for trigonometric terms to be added to the mean elements * of the semi-major axes. * DATA KP / : 69613, 75645, 88306, 59899, 15746, 71087, 142173, 3086, 0, : 21863, 32794, 26934, 10931, 26250, 43725, 53867, 28939, 0, : 16002, 21863, 32004, 10931, 14529, 16368, 15318, 32794, 0, : 6345, 7818, 15636, 7077, 8184, 14163, 1107, 4872, 0, : 1760, 1454, 1167, 880, 287, 2640, 19, 2047, 1454, : 574, 0, 880, 287, 19, 1760, 1167, 306, 574, : 204, 0, 177, 1265, 4, 385, 200, 208, 204, : 0, 102, 106, 4, 98, 1367, 487, 204, 0 / * DATA CA / : 4, -13, 11, -9, -9, -3, -1, 4, 0, : -156, 59, -42, 6, 19, -20, -10, -12, 0, : 64, -152, 62, -8, 32, -41, 19, -11, 0, : 124, 621, -145, 208, 54, -57, 30, 15, 0, : -23437, -2634, 6601, 6259, -1507, -1821, 2620, -2115,-1489, : 62911,-119919, 79336, 17814,-24241, 12068, 8306, -4893, 8902, : 389061,-262125,-44088, 8387,-22976, -2093, -615, -9720, 6633, :-412235,-157046,-31430, 37817, -9740, -13, -7449, 9644, 0 / * DATA SA / : -29, -1, 9, 6, -6, 5, 4, 0, 0, : -48, -125, -26, -37, 18, -13, -20, -2, 0, : -150, -46, 68, 54, 14, 24, -28, 22, 0, : -621, 532, -694, -20, 192, -94, 71, -73, 0, : -14614,-19828, -5869, 1881, -4372, -2255, 782, 930, 913, : 139737, 0, 24667, 51123, -5102, 7429, -4095, -1976,-9566, : -138081, 0, 37205,-49039,-41901,-33872,-27037,-12474,18797, : 0, 28492,133236, 69654, 52322,-49577,-26430, -3593, 0 / * * Tables giving the trigonometric terms to be added to the mean * elements of the mean longitudes. * DATA KQ / : 3086, 15746, 69613, 59899, 75645, 88306, 12661, 2658, 0, 0, : 21863, 32794, 10931, 73, 4387, 26934, 1473, 2157, 0, 0, : 10, 16002, 21863, 10931, 1473, 32004, 4387, 73, 0, 0, : 10, 6345, 7818, 1107, 15636, 7077, 8184, 532, 10, 0, : 19, 1760, 1454, 287, 1167, 880, 574, 2640, 19,1454, : 19, 574, 287, 306, 1760, 12, 31, 38, 19, 574, : 4, 204, 177, 8, 31, 200, 1265, 102, 4, 204, : 4, 102, 106, 8, 98, 1367, 487, 204, 4, 102 / * DATA CL / : 21, -95, -157, 41, -5, 42, 23, 30, 0, 0, : -160, -313, -235, 60, -74, -76, -27, 34, 0, 0, : -325, -322, -79, 232, -52, 97, 55, -41, 0, 0, : 2268, -979, 802, 602, -668, -33, 345, 201, -55, 0, : 7610, -4997,-7689,-5841,-2617, 1115, -748, -607, 6074, 354, : -18549, 30125,20012, -730, 824, 23, 1289, -352,-14767,-2062, :-135245,-14594, 4197,-4030,-5630,-2898, 2540, -306, 2939, 1986, : 89948, 2103, 8963, 2695, 3682, 1648, 866, -154, -1963, -283 / * DATA SL / : -342, 136, -23, 62, 66, -52, -33, 17, 0, 0, : 524, -149, -35, 117, 151, 122, -71, -62, 0, 0, : -105, -137, 258, 35, -116, -88, -112, -80, 0, 0, : 854, -205, -936, -240, 140, -341, -97, -232, 536, 0, : -56980, 8016, 1012, 1448,-3024,-3710, 318, 503, 3767, 577, : 138606,-13478,-4964, 1441,-1319,-1482, 427, 1236, -9167,-1918, : 71234,-41116, 5334,-4935,-1848, 66, 434,-1748, 3780, -701, : -47645, 11647, 2166, 3194, 679, 0, -244, -419, -2531, 48 / * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * Validate the planet number. IF ( NP.LT.1 .OR. NP.GT.8 ) THEN JSTAT = -1 * Reset the result in case of failure. DO 2 K=1,2 DO 1 I=1,3 PV(I,K) = 0D0 1 CONTINUE 2 CONTINUE ELSE * Time: Julian millennia since J2000. T = ( ( DATE1-DJ0 ) + DATE2 ) / DJM * OK status unless remote epoch. IF ( ABS(T) .LE. 1D0 ) THEN JSTAT = 0 ELSE JSTAT = 1 END IF * Compute the mean elements. DA = A(1,NP) + : ( A(2,NP) + : A(3,NP) * T ) * T DL = ( 3600D0 * DLM(1,NP) + : ( DLM(2,NP) + : DLM(3,NP) * T ) * T ) * DAS2R DE = E(1,NP) + : ( E(2,NP) + : E(3,NP) * T ) * T DP = iau_ANPM ( ( 3600D0 * PI(1,NP) + : ( PI(2,NP) + : PI(3,NP) * T ) * T ) * DAS2R ) DI = ( 3600D0 * DINC(1,NP) + : ( DINC(2,NP) + : DINC(3,NP) * T ) * T ) * DAS2R DOM = iau_ANPM ( ( 3600D0 * OMEGA(1,NP) : + ( OMEGA(2,NP) : + OMEGA(3,NP) * T ) * T ) * DAS2R ) * Apply the trigonometric terms. DMU = 0.35953620D0 * T DO 3 K=1,8 ARGA = KP(K,NP) * DMU ARGL = KQ(K,NP) * DMU DA = DA + ( CA(K,NP) * COS(ARGA) + : SA(K,NP) * SIN(ARGA) ) * 1D-7 DL = DL + ( CL(K,NP) * COS(ARGL) + : SL(K,NP) * SIN(ARGL) ) * 1D-7 3 CONTINUE ARGA = KP(9,NP) * DMU DA = DA + T * ( CA(9,NP) * COS(ARGA) + : SA(9,NP) * SIN(ARGA) ) * 1D-7 DO 4 K=9,10 ARGL = KQ(K,NP) * DMU DL = DL + T * ( CL(K,NP) * COS(ARGL) + : SL(K,NP) * SIN(ARGL) ) * 1D-7 4 CONTINUE DL = MOD(DL, D2PI) * Iterative solution of Kepler's equation to get eccentric anomaly. AM = DL - DP AE = AM + DE*SIN(AM) K = 0 5 CONTINUE DAE = ( AM - AE + DE*SIN(AE) ) / ( 1D0 - DE*COS(AE) ) AE = AE + DAE K = K + 1 IF ( K.GE.KMAX ) JSTAT = 2 IF ( K.LT.KMAX .AND. ABS(DAE) .GT. 1D-12 ) GO TO 5 * True anomaly. AE2 = AE / 2D0 AT = 2D0 * ATAN2(SQRT((1D0+DE)/(1D0-DE)) * SIN(AE2), : COS(AE2)) * Distance (AU) and speed (radians per day). R = DA * ( 1D0 - DE*COS(AE) ) V = GK * SQRT( ( 1D0 + 1D0/AMAS(NP) ) / (DA*DA*DA)) SI2 = SIN(DI/2D0) XQ = SI2 * COS(DOM) XP = SI2 * SIN(DOM) TL = AT + DP XSW = SIN(TL) XCW = COS(TL) XM2 = 2D0 * ( XP*XCW - XQ*XSW ) XF = DA / SQRT(1D0 - DE*DE) CI2 = COS(DI/2D0) XMS = ( DE * SIN(DP) + XSW ) * XF XMC = ( DE * COS(DP) + XCW ) * XF XPXQ2 = 2D0 * XP * XQ * Position (J2000 ecliptic x,y,z in AU). X = R * ( XCW - XM2*XP ) Y = R * ( XSW + XM2*XQ ) Z = R * ( -XM2 * CI2 ) * Rotate to equatorial. PV(1,1) = X PV(2,1) = Y*COSEPS - Z*SINEPS PV(3,1) = Y*SINEPS + Z*COSEPS * Velocity (J2000 ecliptic xdot,ydot,zdot in AU/d). X = V * ( ( -1D0 + 2D0*XP*XP ) * XMS + XPXQ2 * XMC ) Y = V * ( ( 1D0 - 2D0*XQ*XQ ) * XMC - XPXQ2 * XMS ) Z = V * ( 2D0 * CI2 * ( XP*XMS + XQ*XMC ) ) * Rotate to equatorial. PV(1,2) = X PV(2,2) = Y*COSEPS - Z*SINEPS PV(3,2) = Y*SINEPS + Z*COSEPS END IF * Return the status. J = JSTAT * Finished. *+---------------------------------------------------------------------- * * Copyright (C) 2008 * Standards Of Fundamental Astronomy Review Board * of the International Astronomical Union. * * ===================== * SOFA Software License * ===================== * * NOTICE TO USER: * * BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING TERMS AND CONDITIONS * WHICH APPLY TO ITS USE. * * 1. The Software is owned by the IAU SOFA Review Board ("the Board"). * * 2. The Software is made available free of charge for use by: * * a) private individuals for non-profit research; and * * b) non-profit educational, academic and research institutions. * * 3. Commercial use of the Software is specifically excluded from the * terms and conditions of this license. Commercial use of the * Software is subject to the prior written agreement of the Board on * terms to be agreed. * * 4. The provision of any version of the Software under the terms and * conditions specified herein does not imply that future versions * will also be made available under the same terms and conditions. * * 5. The user may modify the Software for his/her own purposes. The * user may distribute the modified software provided that the Board * is informed and that a copy of the modified software is made * available to the Board on request. All modifications made by the * user shall be clearly identified to show how the modified software * differs from the original Software, and the name(s) of the * affected routine(s) shall be changed. The original SOFA Software * License text must be present. * * 6. In any published work produced by the user and which includes * results achieved by using the Software, the user shall acknowledge * that the Software was used in producing the information contained * in such publication. * * 7. The user may incorporate or embed the Software into other software * products which he/she may then give away free of charge but not * sell provided the user makes due acknowledgement of the use which * he/she has made of the Software in creating such software * products. Any redistribution of the Software in this way shall be * made under the same terms and conditions under which the user * received it from the SOFA Center. * * 8. The user shall not cause the Software to be brought into * disrepute, either by misuse, or use for inappropriate tasks, or by * inappropriate modification. * * 9. The Software is provided to the user "as is" and the Board makes * no warranty as to its use or performance. The Board does not and * cannot warrant the performance or results which the user may * obtain by using the Software. The Board makes no warranties, * express or implied, as to non-infringement of third party rights, * merchantability, or fitness for any particular purpose. In no * event will the Board be liable to the user for any consequential, * incidental, or special damages, including any lost profits or lost * savings, even if a Board representative has been advised of such * damages, or for any claim by any third party. * * Correspondence concerning SOFA software should be addressed as * follows: * * Internet email: sofa@rl.ac.uk * Postal address: IAU SOFA Center * Rutherford Appleton Laboratory * Chilton, Didcot, Oxon OX11 0QX * United Kingdom * * *----------------------------------------------------------------------- END