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Diffstat (limited to 'ast/erfa/nut80.c')
-rw-r--r-- | ast/erfa/nut80.c | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/ast/erfa/nut80.c b/ast/erfa/nut80.c new file mode 100644 index 0000000..5ffb23c --- /dev/null +++ b/ast/erfa/nut80.c @@ -0,0 +1,334 @@ +#include "erfa.h" + +void eraNut80(double date1, double date2, double *dpsi, double *deps) +/* +** - - - - - - - - - +** e r a N u t 8 0 +** - - - - - - - - - +** +** Nutation, IAU 1980 model. +** +** Given: +** date1,date2 double TT as a 2-part Julian Date (Note 1) +** +** Returned: +** dpsi double nutation in longitude (radians) +** deps double nutation in obliquity (radians) +** +** Notes: +** +** 1) The TT date date1+date2 is a Julian Date, apportioned in any +** convenient way between the two arguments. For example, +** JD(TT)=2450123.7 could be expressed in any of these ways, +** among others: +** +** date1 date2 +** +** 2450123.7 0.0 (JD method) +** 2451545.0 -1421.3 (J2000 method) +** 2400000.5 50123.2 (MJD method) +** 2450123.5 0.2 (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. +** +** 2) The nutation components are with respect to the ecliptic of +** date. +** +** Called: +** eraAnpm normalize angle into range +/- pi +** +** Reference: +** +** Explanatory Supplement to the Astronomical Almanac, +** P. Kenneth Seidelmann (ed), University Science Books (1992), +** Section 3.222 (p111). +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + double t, el, elp, f, d, om, dp, de, arg, s, c; + int j; + +/* Units of 0.1 milliarcsecond to radians */ + const double U2R = ERFA_DAS2R / 1e4; + +/* ------------------------------------------------ */ +/* Table of multiples of arguments and coefficients */ +/* ------------------------------------------------ */ + +/* The units for the sine and cosine coefficients are 0.1 mas and */ +/* the same per Julian century */ + + static const struct { + int nl,nlp,nf,nd,nom; /* coefficients of l,l',F,D,Om */ + double sp,spt; /* longitude sine, 1 and t coefficients */ + double ce,cet; /* obliquity cosine, 1 and t coefficients */ + } x[] = { + + /* 1-10 */ + { 0, 0, 0, 0, 1, -171996.0, -174.2, 92025.0, 8.9 }, + { 0, 0, 0, 0, 2, 2062.0, 0.2, -895.0, 0.5 }, + { -2, 0, 2, 0, 1, 46.0, 0.0, -24.0, 0.0 }, + { 2, 0, -2, 0, 0, 11.0, 0.0, 0.0, 0.0 }, + { -2, 0, 2, 0, 2, -3.0, 0.0, 1.0, 0.0 }, + { 1, -1, 0, -1, 0, -3.0, 0.0, 0.0, 0.0 }, + { 0, -2, 2, -2, 1, -2.0, 0.0, 1.0, 0.0 }, + { 2, 0, -2, 0, 1, 1.0, 0.0, 0.0, 0.0 }, + { 0, 0, 2, -2, 2, -13187.0, -1.6, 5736.0, -3.1 }, + { 0, 1, 0, 0, 0, 1426.0, -3.4, 54.0, -0.1 }, + + /* 11-20 */ + { 0, 1, 2, -2, 2, -517.0, 1.2, 224.0, -0.6 }, + { 0, -1, 2, -2, 2, 217.0, -0.5, -95.0, 0.3 }, + { 0, 0, 2, -2, 1, 129.0, 0.1, -70.0, 0.0 }, + { 2, 0, 0, -2, 0, 48.0, 0.0, 1.0, 0.0 }, + { 0, 0, 2, -2, 0, -22.0, 0.0, 0.0, 0.0 }, + { 0, 2, 0, 0, 0, 17.0, -0.1, 0.0, 0.0 }, + { 0, 1, 0, 0, 1, -15.0, 0.0, 9.0, 0.0 }, + { 0, 2, 2, -2, 2, -16.0, 0.1, 7.0, 0.0 }, + { 0, -1, 0, 0, 1, -12.0, 0.0, 6.0, 0.0 }, + { -2, 0, 0, 2, 1, -6.0, 0.0, 3.0, 0.0 }, + + /* 21-30 */ + { 0, -1, 2, -2, 1, -5.0, 0.0, 3.0, 0.0 }, + { 2, 0, 0, -2, 1, 4.0, 0.0, -2.0, 0.0 }, + { 0, 1, 2, -2, 1, 4.0, 0.0, -2.0, 0.0 }, + { 1, 0, 0, -1, 0, -4.0, 0.0, 0.0, 0.0 }, + { 2, 1, 0, -2, 0, 1.0, 0.0, 0.0, 0.0 }, + { 0, 0, -2, 2, 1, 1.0, 0.0, 0.0, 0.0 }, + { 0, 1, -2, 2, 0, -1.0, 0.0, 0.0, 0.0 }, + { 0, 1, 0, 0, 2, 1.0, 0.0, 0.0, 0.0 }, + { -1, 0, 0, 1, 1, 1.0, 0.0, 0.0, 0.0 }, + { 0, 1, 2, -2, 0, -1.0, 0.0, 0.0, 0.0 }, + + /* 31-40 */ + { 0, 0, 2, 0, 2, -2274.0, -0.2, 977.0, -0.5 }, + { 1, 0, 0, 0, 0, 712.0, 0.1, -7.0, 0.0 }, + { 0, 0, 2, 0, 1, -386.0, -0.4, 200.0, 0.0 }, + { 1, 0, 2, 0, 2, -301.0, 0.0, 129.0, -0.1 }, + { 1, 0, 0, -2, 0, -158.0, 0.0, -1.0, 0.0 }, + { -1, 0, 2, 0, 2, 123.0, 0.0, -53.0, 0.0 }, + { 0, 0, 0, 2, 0, 63.0, 0.0, -2.0, 0.0 }, + { 1, 0, 0, 0, 1, 63.0, 0.1, -33.0, 0.0 }, + { -1, 0, 0, 0, 1, -58.0, -0.1, 32.0, 0.0 }, + { -1, 0, 2, 2, 2, -59.0, 0.0, 26.0, 0.0 }, + + /* 41-50 */ + { 1, 0, 2, 0, 1, -51.0, 0.0, 27.0, 0.0 }, + { 0, 0, 2, 2, 2, -38.0, 0.0, 16.0, 0.0 }, + { 2, 0, 0, 0, 0, 29.0, 0.0, -1.0, 0.0 }, + { 1, 0, 2, -2, 2, 29.0, 0.0, -12.0, 0.0 }, + { 2, 0, 2, 0, 2, -31.0, 0.0, 13.0, 0.0 }, + { 0, 0, 2, 0, 0, 26.0, 0.0, -1.0, 0.0 }, + { -1, 0, 2, 0, 1, 21.0, 0.0, -10.0, 0.0 }, + { -1, 0, 0, 2, 1, 16.0, 0.0, -8.0, 0.0 }, + { 1, 0, 0, -2, 1, -13.0, 0.0, 7.0, 0.0 }, + { -1, 0, 2, 2, 1, -10.0, 0.0, 5.0, 0.0 }, + + /* 51-60 */ + { 1, 1, 0, -2, 0, -7.0, 0.0, 0.0, 0.0 }, + { 0, 1, 2, 0, 2, 7.0, 0.0, -3.0, 0.0 }, + { 0, -1, 2, 0, 2, -7.0, 0.0, 3.0, 0.0 }, + { 1, 0, 2, 2, 2, -8.0, 0.0, 3.0, 0.0 }, + { 1, 0, 0, 2, 0, 6.0, 0.0, 0.0, 0.0 }, + { 2, 0, 2, -2, 2, 6.0, 0.0, -3.0, 0.0 }, + { 0, 0, 0, 2, 1, -6.0, 0.0, 3.0, 0.0 }, + { 0, 0, 2, 2, 1, -7.0, 0.0, 3.0, 0.0 }, + { 1, 0, 2, -2, 1, 6.0, 0.0, -3.0, 0.0 }, + { 0, 0, 0, -2, 1, -5.0, 0.0, 3.0, 0.0 }, + + /* 61-70 */ + { 1, -1, 0, 0, 0, 5.0, 0.0, 0.0, 0.0 }, + { 2, 0, 2, 0, 1, -5.0, 0.0, 3.0, 0.0 }, + { 0, 1, 0, -2, 0, -4.0, 0.0, 0.0, 0.0 }, + { 1, 0, -2, 0, 0, 4.0, 0.0, 0.0, 0.0 }, + { 0, 0, 0, 1, 0, -4.0, 0.0, 0.0, 0.0 }, + { 1, 1, 0, 0, 0, -3.0, 0.0, 0.0, 0.0 }, + { 1, 0, 2, 0, 0, 3.0, 0.0, 0.0, 0.0 }, + { 1, -1, 2, 0, 2, -3.0, 0.0, 1.0, 0.0 }, + { -1, -1, 2, 2, 2, -3.0, 0.0, 1.0, 0.0 }, + { -2, 0, 0, 0, 1, -2.0, 0.0, 1.0, 0.0 }, + + /* 71-80 */ + { 3, 0, 2, 0, 2, -3.0, 0.0, 1.0, 0.0 }, + { 0, -1, 2, 2, 2, -3.0, 0.0, 1.0, 0.0 }, + { 1, 1, 2, 0, 2, 2.0, 0.0, -1.0, 0.0 }, + { -1, 0, 2, -2, 1, -2.0, 0.0, 1.0, 0.0 }, + { 2, 0, 0, 0, 1, 2.0, 0.0, -1.0, 0.0 }, + { 1, 0, 0, 0, 2, -2.0, 0.0, 1.0, 0.0 }, + { 3, 0, 0, 0, 0, 2.0, 0.0, 0.0, 0.0 }, + { 0, 0, 2, 1, 2, 2.0, 0.0, -1.0, 0.0 }, + { -1, 0, 0, 0, 2, 1.0, 0.0, -1.0, 0.0 }, + { 1, 0, 0, -4, 0, -1.0, 0.0, 0.0, 0.0 }, + + /* 81-90 */ + { -2, 0, 2, 2, 2, 1.0, 0.0, -1.0, 0.0 }, + { -1, 0, 2, 4, 2, -2.0, 0.0, 1.0, 0.0 }, + { 2, 0, 0, -4, 0, -1.0, 0.0, 0.0, 0.0 }, + { 1, 1, 2, -2, 2, 1.0, 0.0, -1.0, 0.0 }, + { 1, 0, 2, 2, 1, -1.0, 0.0, 1.0, 0.0 }, + { -2, 0, 2, 4, 2, -1.0, 0.0, 1.0, 0.0 }, + { -1, 0, 4, 0, 2, 1.0, 0.0, 0.0, 0.0 }, + { 1, -1, 0, -2, 0, 1.0, 0.0, 0.0, 0.0 }, + { 2, 0, 2, -2, 1, 1.0, 0.0, -1.0, 0.0 }, + { 2, 0, 2, 2, 2, -1.0, 0.0, 0.0, 0.0 }, + + /* 91-100 */ + { 1, 0, 0, 2, 1, -1.0, 0.0, 0.0, 0.0 }, + { 0, 0, 4, -2, 2, 1.0, 0.0, 0.0, 0.0 }, + { 3, 0, 2, -2, 2, 1.0, 0.0, 0.0, 0.0 }, + { 1, 0, 2, -2, 0, -1.0, 0.0, 0.0, 0.0 }, + { 0, 1, 2, 0, 1, 1.0, 0.0, 0.0, 0.0 }, + { -1, -1, 0, 2, 1, 1.0, 0.0, 0.0, 0.0 }, + { 0, 0, -2, 0, 1, -1.0, 0.0, 0.0, 0.0 }, + { 0, 0, 2, -1, 2, -1.0, 0.0, 0.0, 0.0 }, + { 0, 1, 0, 2, 0, -1.0, 0.0, 0.0, 0.0 }, + { 1, 0, -2, -2, 0, -1.0, 0.0, 0.0, 0.0 }, + + /* 101-106 */ + { 0, -1, 2, 0, 1, -1.0, 0.0, 0.0, 0.0 }, + { 1, 1, 0, -2, 1, -1.0, 0.0, 0.0, 0.0 }, + { 1, 0, -2, 2, 0, -1.0, 0.0, 0.0, 0.0 }, + { 2, 0, 0, 2, 0, 1.0, 0.0, 0.0, 0.0 }, + { 0, 0, 2, 4, 2, -1.0, 0.0, 0.0, 0.0 }, + { 0, 1, 0, 1, 0, 1.0, 0.0, 0.0, 0.0 } + }; + +/* Number of terms in the series */ + const int NT = (int) (sizeof x / sizeof x[0]); + +/*--------------------------------------------------------------------*/ + +/* Interval between fundamental epoch J2000.0 and given date (JC). */ + t = ((date1 - ERFA_DJ00) + date2) / ERFA_DJC; + +/* --------------------- */ +/* Fundamental arguments */ +/* --------------------- */ + +/* Mean longitude of Moon minus mean longitude of Moon's perigee. */ + el = eraAnpm( + (485866.733 + (715922.633 + (31.310 + 0.064 * t) * t) * t) + * ERFA_DAS2R + fmod(1325.0 * t, 1.0) * ERFA_D2PI); + +/* Mean longitude of Sun minus mean longitude of Sun's perigee. */ + elp = eraAnpm( + (1287099.804 + (1292581.224 + (-0.577 - 0.012 * t) * t) * t) + * ERFA_DAS2R + fmod(99.0 * t, 1.0) * ERFA_D2PI); + +/* Mean longitude of Moon minus mean longitude of Moon's node. */ + f = eraAnpm( + (335778.877 + (295263.137 + (-13.257 + 0.011 * t) * t) * t) + * ERFA_DAS2R + fmod(1342.0 * t, 1.0) * ERFA_D2PI); + +/* Mean elongation of Moon from Sun. */ + d = eraAnpm( + (1072261.307 + (1105601.328 + (-6.891 + 0.019 * t) * t) * t) + * ERFA_DAS2R + fmod(1236.0 * t, 1.0) * ERFA_D2PI); + +/* Longitude of the mean ascending node of the lunar orbit on the */ +/* ecliptic, measured from the mean equinox of date. */ + om = eraAnpm( + (450160.280 + (-482890.539 + (7.455 + 0.008 * t) * t) * t) + * ERFA_DAS2R + fmod(-5.0 * t, 1.0) * ERFA_D2PI); + +/* --------------- */ +/* Nutation series */ +/* --------------- */ + +/* Initialize nutation components. */ + dp = 0.0; + de = 0.0; + +/* Sum the nutation terms, ending with the biggest. */ + for (j = NT-1; j >= 0; j--) { + + /* Form argument for current term. */ + arg = (double)x[j].nl * el + + (double)x[j].nlp * elp + + (double)x[j].nf * f + + (double)x[j].nd * d + + (double)x[j].nom * om; + + /* Accumulate current nutation term. */ + s = x[j].sp + x[j].spt * t; + c = x[j].ce + x[j].cet * t; + if (s != 0.0) dp += s * sin(arg); + if (c != 0.0) de += c * cos(arg); + } + +/* Convert results from 0.1 mas units to radians. */ + *dpsi = dp * U2R; + *deps = de * U2R; + + return; + +} +/*---------------------------------------------------------------------- +** +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** All rights reserved. +** +** This library is derived, with permission, from the International +** Astronomical Union's "Standards of Fundamental Astronomy" library, +** available from http://www.iausofa.org. +** +** The ERFA version is intended to retain identical functionality to +** the SOFA library, but made distinct through different function and +** file names, as set out in the SOFA license conditions. The SOFA +** original has a role as a reference standard for the IAU and IERS, +** and consequently redistribution is permitted only in its unaltered +** state. The ERFA version is not subject to this restriction and +** therefore can be included in distributions which do not support the +** concept of "read only" software. +** +** Although the intent is to replicate the SOFA API (other than +** replacement of prefix names) and results (with the exception of +** bugs; any that are discovered will be fixed), SOFA is not +** responsible for any errors found in this version of the library. +** +** If you wish to acknowledge the SOFA heritage, please acknowledge +** that you are using a library derived from SOFA, rather than SOFA +** itself. +** +** +** TERMS AND CONDITIONS +** +** Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions +** are met: +** +** 1 Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** +** 2 Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** +** 3 Neither the name of the Standards Of Fundamental Astronomy Board, +** the International Astronomical Union nor the names of its +** contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +** POSSIBILITY OF SUCH DAMAGE. +** +*/ |