Subversion Repositories planix.SVN

#include "astro.h"

double k1, k2, k3, k4;

double mnom, msun, noded, dmoon;

void

moon(void)

{

	Moontab *mp;

	double dlong, lsun, psun;

	double eccm, eccs, chp, cpe;

	double v0, t0, m0, j0;

	double arg1, arg2, arg3, arg4, arg5, arg6, arg7;

	double arg8, arg9, arg10;

	double dgamma, k5, k6;

	double lterms, sterms, cterms, nterms, pterms, spterms;

	double gamma1, gamma2, gamma3, arglat;

	double xmp, ymp, zmp;

	double obl2;

/*

 *	the fundamental elements - all referred to the epoch of

 *	Jan 0.5, 1900 and to the mean equinox of date.

 */

	dlong = 270.434164 + 13.1763965268*eday - .001133*capt2

		 + 2.e-6*capt3;

	argp = 334.329556 + .1114040803*eday - .010325*capt2

		 - 12.e-6*capt3;

	node = 259.183275 - .0529539222*eday + .002078*capt2

		 + 2.e-6*capt3;

	lsun = 279.696678 + .9856473354*eday + .000303*capt2;

	psun = 281.220833 + .0000470684*eday + .000453*capt2

		 + 3.e-6*capt3;

	dlong = fmod(dlong, 360.);

	argp = fmod(argp, 360.);

	node = fmod(node, 360.);

	lsun = fmod(lsun, 360.);

	psun = fmod(psun, 360.);

	eccm = 22639.550;

	eccs = .01675104 - .00004180*capt;

	incl = 18461.400;

	cpe = 124.986;

	chp = 3422.451;

/*

 *	some subsidiary elements - they are all longitudes

 *	and they are referred to the epoch 1/0.5 1900 and

 *	to the fixed mean equinox of 1850.0.

 */

	v0 = 342.069128 + 1.6021304820*eday;

	t0 =  98.998753 + 0.9856091138*eday;

	m0 = 293.049675 + 0.5240329445*eday;

	j0 = 237.352319 + 0.0830912295*eday;

/*

 *	the following are periodic corrections to the

 *	fundamental elements and constants.

 *	arg3 is the "Great Venus Inequality".

 */

	arg1 = 41.1 + 20.2*(capt+.5);

	arg2 = dlong - argp + 33. + 3.*t0 - 10.*v0 - 2.6*(capt+.5);

	arg3 = dlong - argp + 151.1 + 16.*t0 - 18.*v0 - (capt+.5);

	arg4 = node;

	arg5 = node + 276.2 - 2.3*(capt+.5);

	arg6 = 313.9 + 13.*t0 - 8.*v0;

	arg7 = dlong - argp + 112.0 + 29.*t0 - 26.*v0;

	arg8 = dlong + argp - 2.*lsun + 273. + 21.*t0 - 20.*v0;

	arg9 = node + 290.1 - 0.9*(capt+.5);

	arg10 = 115. + 38.5*(capt+.5);

	arg1 *= radian;

	arg2 *= radian;

	arg3 *= radian;

	arg4 *= radian;

	arg5 *= radian;

	arg6 *= radian;

	arg7 *= radian;

	arg8 *= radian;

	arg9 *= radian;

	arg10 *= radian;

	dlong +=

		   (0.84 *sin(arg1)

		 +  0.31 *sin(arg2)

		 + 14.27 *sin(arg3)

		 +  7.261*sin(arg4)

		 +  0.282*sin(arg5)

		 +  0.237*sin(arg6)

		 +  0.108*sin(arg7)

		 +  0.126*sin(arg8))/3600.;

	argp +=

		 (- 2.10 *sin(arg1)

		 -  0.118*sin(arg3)

		 -  2.076*sin(arg4)

		 -  0.840*sin(arg5)

		 -  0.593*sin(arg6))/3600.;

	node +=

		   (0.63*sin(arg1)

		 +  0.17*sin(arg3)

		 + 95.96*sin(arg4)

		 + 15.58*sin(arg5)

		 +  1.86*sin(arg9))/3600.;

	t0 +=

		 (- 6.40*sin(arg1)

		 -  1.89*sin(arg6))/3600.;

	psun +=

		   (6.40*sin(arg1)

		 +  1.89*sin(arg6))/3600.;

	dgamma = -  4.318*cos(arg4)

		 -  0.698*cos(arg5)

		 -  0.083*cos(arg9);

	j0 +=

		   0.33*sin(arg10);

/*

 *	the following factors account for the fact that the

 *	eccentricity, solar eccentricity, inclination and

 *	parallax used by Brown to make up his coefficients

 *	are both wrong and out of date.  Brown did the same

 *	thing in a different way.

 */

	k1 = eccm/22639.500;

	k2 = eccs/.01675104;

	k3 = 1. + 2.708e-6 + .000108008*dgamma;

	k4 = cpe/125.154;

	k5 = chp/3422.700;

/*

 *	the principal arguments that are used to compute

 *	perturbations are the following differences of the

 *	fundamental elements.

 */

	mnom = dlong - argp;

	msun = lsun - psun;

	noded = dlong - node;

	dmoon = dlong - lsun;

/*

 *	solar terms in longitude

 */

	lterms = 0.0;

	mp = moontab;

	for(;;) {

		if(mp->f == 0.0)

			break;

		lterms += sinx(mp->f,

			mp->c[0], mp->c[1],

			mp->c[2], mp->c[3], 0.0);

		mp++;

	}

	mp++;

/*

 *	planetary terms in longitude

 */

	lterms += sinx(0.822, 0,0,0,0, t0-v0);

	lterms += sinx(0.307, 0,0,0,0, 2.*t0-2.*v0+179.8);

	lterms += sinx(0.348, 0,0,0,0, 3.*t0-2.*v0+272.9);

	lterms += sinx(0.176, 0,0,0,0, 4.*t0-3.*v0+271.7);

	lterms += sinx(0.092, 0,0,0,0, 5.*t0-3.*v0+199.);

	lterms += sinx(0.129, 1,0,0,0, -t0+v0+180.);

	lterms += sinx(0.152, 1,0,0,0, t0-v0);

	lterms += sinx(0.127, 1,0,0,0, 3.*t0-3.*v0+180.);

	lterms += sinx(0.099, 0,0,0,2, t0-v0);

	lterms += sinx(0.136, 0,0,0,2, 2.*t0-2.*v0+179.5);

	lterms += sinx(0.083, -1,0,0,2, -4.*t0+4.*v0+180.);

	lterms += sinx(0.662, -1,0,0,2, -3.*t0+3.*v0+180.0);

	lterms += sinx(0.137, -1,0,0,2, -2.*t0+2.*v0);

	lterms += sinx(0.133, -1,0,0,2, t0-v0);

	lterms += sinx(0.157, -1,0,0,2, 2.*t0-2.*v0+179.6);

	lterms += sinx(0.079, -1,0,0,2, -8.*t0+6.*v0+162.6);

	lterms += sinx(0.073, 2,0,0,-2, 3.*t0-3.*v0+180.);

	lterms += sinx(0.643, 0,0,0,0, -t0+j0+178.8);

	lterms += sinx(0.187, 0,0,0,0, -2.*t0+2.*j0+359.6);

	lterms += sinx(0.087, 0,0,0,0, j0+289.9);

	lterms += sinx(0.165, 0,0,0,0, -t0+2.*j0+241.5);

	lterms += sinx(0.144, 1,0,0,0, t0-j0+1.0);

	lterms += sinx(0.158, 1,0,0,0, -t0+j0+179.0);

	lterms += sinx(0.190, 1,0,0,0, -2.*t0+2.*j0+180.0);

	lterms += sinx(0.096, 1,0,0,0, -2.*t0+3.*j0+352.5);

	lterms += sinx(0.070, 0,0,0,2, 2.*t0-2.*j0+180.);

	lterms += sinx(0.167, 0,0,0,2, -t0+j0+178.5);

	lterms += sinx(0.085, 0,0,0,2, -2.*t0+2.*j0+359.2);

	lterms += sinx(1.137, -1,0,0,2, 2.*t0-2.*j0+180.3);

	lterms += sinx(0.211, -1,0,0,2, -t0+j0+178.4);

	lterms += sinx(0.089, -1,0,0,2, -2.*t0+2.*j0+359.2);

	lterms += sinx(0.436, -1,0,0,2, 2.*t0-3.*j0+7.5);

	lterms += sinx(0.240, 2,0,0,-2, -2.*t0+2.*j0+179.9);

	lterms += sinx(0.284, 2,0,0,-2, -2.*t0+3.*j0+172.5);

	lterms += sinx(0.195, 0,0,0,0, -2.*t0+2.*m0+180.2);

	lterms += sinx(0.327, 0,0,0,0, -t0+2.*m0+224.4);

	lterms += sinx(0.093, 0,0,0,0, -2.*t0+4.*m0+244.8);

	lterms += sinx(0.073, 1,0,0,0, -t0+2.*m0+223.3);

	lterms += sinx(0.074, 1,0,0,0, t0-2.*m0+306.3);

	lterms += sinx(0.189, 0,0,0,0, node+180.);

/*

 *	solar terms in latitude

 */

	sterms = 0;

	for(;;) {

		if(mp->f == 0)

			break;

		sterms += sinx(mp->f,

			mp->c[0], mp->c[1],

			mp->c[2], mp->c[3], 0);

		mp++;

	}

	mp++;

	cterms = 0;

	for(;;) {

		if(mp->f == 0)

			break;

		cterms += cosx(mp->f,

			mp->c[0], mp->c[1],

			mp->c[2], mp->c[3], 0);

		mp++;

	}

	mp++;

	nterms = 0;

	for(;;) {

		if(mp->f == 0)

			break;

		nterms += sinx(mp->f,

			mp->c[0], mp->c[1],

			mp->c[2], mp->c[3], 0);

		mp++;

	}

	mp++;

/*

 *	planetary terms in latitude

 */

	pterms =

		   sinx(0.215, 0,0,0,0, dlong);

/*

 *	solar terms in parallax

 */

	spterms = 3422.700;

	for(;;) {

		if(mp->f == 0)

			break;

		spterms += cosx(mp->f,

			mp->c[0], mp->c[1],

			mp->c[2], mp->c[3], 0);

		mp++;

	}

/*

 *	planetary terms in parallax

 */

	spterms = spterms;

/*

 *	computation of longitude

 */

	lambda = (dlong + lterms/3600.)*radian;

/*

 *	computation of latitude

 */

	arglat = (noded + sterms/3600.)*radian;

	gamma1 = 18519.700 * k3;

	gamma2 = -6.241 * k3*k3*k3;

	gamma3 = 0.004 * k3*k3*k3*k3*k3;

	k6 = (gamma1 + cterms) / gamma1;

	beta = k6 * (gamma1*sin(arglat) + gamma2*sin(3.*arglat)

		 + gamma3*sin(5.*arglat) + nterms)

		 + pterms;

	if(flags['o'])

		beta -= 0.6;

	beta *= radsec;

/*

 *	computation of parallax

 */

	spterms = k5 * spterms *radsec;

	hp = spterms + (spterms*spterms*spterms)/6.;

	rad = hp/radsec;

	rp = 1.;

	semi = .0799 + .272453*(hp/radsec);

	if(dmoon < 0.)

		dmoon += 360.;

	mag = dmoon/360.;

/*

 *	change to equatorial coordinates

 */

	lambda += phi;

	obl2 = obliq + eps;

	xmp = rp*cos(lambda)*cos(beta);

	ymp = rp*(sin(lambda)*cos(beta)*cos(obl2) - sin(obl2)*sin(beta));

	zmp = rp*(sin(lambda)*cos(beta)*sin(obl2) + cos(obl2)*sin(beta));

	alpha = atan2(ymp, xmp);

	delta = atan2(zmp, sqrt(xmp*xmp+ymp*ymp));

	meday = eday;

	mhp = hp;

	geo();

}

double

sinx(double coef, int i, int j, int k, int m, double angle)

{

	double x;

	x = i*mnom + j*msun + k*noded + m*dmoon + angle;

	x = coef*sin(x*radian);

	if(i < 0)

		i = -i;

	for(; i>0; i--)

		x *= k1;

	if(j < 0)

		j = -j;

	for(; j>0; j--)

		x *= k2;

	if(k < 0)

		k = -k;

	for(; k>0; k--)

		x *= k3;

	if(m & 1)

		x *= k4;

	return x;

}

double

cosx(double coef, int i, int j, int k, int m, double angle)

{

	double x;

	x = i*mnom + j*msun + k*noded + m*dmoon + angle;

	x = coef*cos(x*radian);

	if(i < 0)

		i = -i;

	for(; i>0; i--)

		x *= k1;

	if(j < 0)

		j = -j;

	for(; j>0; j--)

		x *= k2;

	if(k < 0)

		k = -k;

	for(; k>0; k--)

		x *= k3;

	if(m & 1)

		x *= k4;

	return x;

}