/*******************************************************************************
* NAME:
* AppSolarCoordinates
*
* PURPOSE:
* Computes the apparent coordinates of the sun
*
* REFERENCES;
* Meeus, Jean. "Astronomical Algorithms, 1st ed." Willmann-Bell. Inc. 1991.
* pp. 151-153
*
* INPUT ARGUMENTS:
* JD (double)
* Julian Day for day/time to calculate at TD
*
* OUTPUT ARGUMENTS:
* *alpha (double)
* apparent right ascention in degrees
* *delta (double)
* apparent declination in degrees
*
* RETURNED VALUE:
* none yet
*
* GLOBALS USED:
* none
*
* FUNCTIONS CALLED:
* SinD, CosD, Revolution, atan2
*
* DATE/PROGRAMMER/NOTE:
* 09-16-1999 Todd A. Guillory created
* 07-04-2000 Todd A. Guillory condensed equations some more
* 07-27-2000 Todd A. Guillory checked with example 24.a
*
********************************************************************************/
void app_solar_coordinates( double JD, double *alpha, double *delta)
{
double T, /* Julian Centuries */
L0, /* geometric mean longitude of the sun */
M, /* mean anomoly */
e, /* eccentricity of Earth's orbit */
C, /* Sun's equation of center */
Long, /* true longitude of the sun */
v, /* true anomaly of the sun */
R, /* Radius in AU */
omega, /* nutation */
lamda, /* apparent longitude of the sun */
ep0; /* mean obliquity of the ecliptic */
/* Get Julian Centuries */
T = julian_centuries(JD);
/* calculate the geometric mean longitude of the sun */
L0 = 280.46645 + 36000.76983 * T + 0.0003032 * T * T;
/* calculate the mean anomaly of the sun */
M = 357.52910 + 35999.05030 * T - 0.0001559 * T * T - 0.00000048 * T * T * T;
/* calculate the eccentricity of the Earth's Orbit */
e = 0.016708617 - 0.000042037 * T - 0.0000001236 * T * T;
/* calculate the sun's equation of center */
C = (1.914600 - 0.004817 * T - 0.000014 * T * T) * SinD(M)
+ (0.019993 - 0.000101 * T) * SinD(2*M)
+ 0.000290 * SinD(3*M);
/* calculate the sun's true longitude */
Long = L0 + C;
/* calculate the true anomaly */
v = M + C;
/* calculate the sun's radius vector, distance of the earth in AUs */
R = (1.000001018 * ( 1 - e * e)) / ( 1 + e * CosD(v) );
omega = 125.04 - 1934.136 * T;
/* calculate the apparent longitude of the sun */
lamda = Revolution(Long - 0.00569 - 0.00478 * SinD(omega));
/* calculate the mean obliquity of the ecliptic */
ep0 = ((23*60)+26)*60+21.448 - 46.8150 * T - 0.00059 * T * T + 0.001813 * T * T * T;
ep0 /= 3600;
/* correct mean obliquity of the ecliptic */
ep0 = ep0 + 0.00256 * CosD(omega);
/* calculate right ascension and declination */
*alpha = Revolution(atan2(CosD(ep0) * SinD(lamda), CosD(lamda)) * kRadDeg);
*delta = asin(SinD(ep0) * SinD(lamda)) * kRadDeg;
}
int
lunar_longitude( mpfr_t *result, mpfr_t *moment ) {
mpfr_t C, mean_moon, elongation, solar_anomaly, lunar_anomaly, moon_node, E, correction, venus, jupiter, flat_earth, N, fullangle;
mpfr_init(C);
julian_centuries( &C, moment );
{
mpfr_t a, b, c, d, e;
mpfr_init(mean_moon);
mpfr_init_set_d(a, 218.316591, GMP_RNDN);
mpfr_init_set_d(b, 481267.88134236, GMP_RNDN);
mpfr_init_set_d(c, -0.0013268, GMP_RNDN);
mpfr_init_set_ui(d, 1, GMP_RNDN);
mpfr_div_ui(d, d, 538841, GMP_RNDN);
mpfr_init_set_si(e, -1, GMP_RNDN);
mpfr_div_ui(e, e, 65194000, GMP_RNDN);
polynomial( &mean_moon, &C, 5, &a, &b, &c, &d, &e );
mpfr_clear(a);
mpfr_clear(b);
mpfr_clear(c);
mpfr_clear(d);
mpfr_clear(e);
}
{
mpfr_t a, b, c, d, e;
mpfr_init(elongation);
mpfr_init_set_d(a, 297.8502042, GMP_RNDN);
mpfr_init_set_d(b, 445267.1115168, GMP_RNDN);
mpfr_init_set_d(c, -0.00163, GMP_RNDN);
mpfr_init_set_ui(d, 1, GMP_RNDN);
mpfr_div_ui(d, d, 545868, GMP_RNDN);
mpfr_init_set_si(e, -1, GMP_RNDN);
mpfr_div_ui(e, e, 113065000, GMP_RNDN);
polynomial( &elongation, &C, 5, &a, &b, &c, &d, &e );
mpfr_clear(a);
mpfr_clear(b);
mpfr_clear(c);
mpfr_clear(d);
mpfr_clear(e);
}
{
mpfr_t a, b, c, d;
mpfr_init(solar_anomaly);
mpfr_init_set_d(a, 357.5291092, GMP_RNDN);
mpfr_init_set_d(b, 35999.0502909, GMP_RNDN);
mpfr_init_set_d(c, -0.0001536, GMP_RNDN);
mpfr_init_set_ui(d, 1, GMP_RNDN);
mpfr_div_ui(d, d, 24490000, GMP_RNDN);
polynomial( &solar_anomaly, &C, 4, &a, &b, &c, &d );
mpfr_clear(a);
mpfr_clear(b);
mpfr_clear(c);
mpfr_clear(d);
}
{
mpfr_t a, b, c, d, e;
mpfr_init(lunar_anomaly);
mpfr_init_set_d(a, 134.9634114, GMP_RNDN);
mpfr_init_set_d(b, 477198.8676313, GMP_RNDN);
mpfr_init_set_d(c, 0.0008997, GMP_RNDN);
mpfr_init_set_ui(d, 1, GMP_RNDN);
mpfr_div_ui(d, d, 69699, GMP_RNDN);
mpfr_init_set_si(e, -1, GMP_RNDN);
mpfr_div_ui(e, e, 14712000, GMP_RNDN);
polynomial( &lunar_anomaly, &C, 5, &a, &b, &c, &d, &e);
mpfr_clear(a);
mpfr_clear(b);
mpfr_clear(c);
mpfr_clear(d);
mpfr_clear(e);
}
{
mpfr_t a, b, c, d, e;
mpfr_init(moon_node);
mpfr_init_set_d(a, 93.2720993, GMP_RNDN);
mpfr_init_set_d(b, 483202.0175273, GMP_RNDN);
mpfr_init_set_d(c, -0.0034029, GMP_RNDN);
mpfr_init_set_si(d, -1, GMP_RNDN);
mpfr_div_ui(d, d, 3526000, GMP_RNDN);
mpfr_init_set_ui(e, 1, GMP_RNDN);
mpfr_div_ui(e, e, 863310000, GMP_RNDN);
polynomial(&moon_node, &C, 5, &a, &b, &c, &d, &e);
mpfr_clear(a);
mpfr_clear(b);
mpfr_clear(c);
mpfr_clear(d);
mpfr_clear(e);
}
{
mpfr_t a, b, c;
mpfr_init(E);
mpfr_init_set_ui(a, 1, GMP_RNDN);
mpfr_init_set_d(b, -0.002516, GMP_RNDN);
mpfr_init_set_d(c, -0.0000074, GMP_RNDN);
polynomial( &E, &C, 3, &a, &b, &c );
mpfr_clear(a);
mpfr_clear(b);
mpfr_clear(c);
}
{
int i;
mpfr_t fugly;
mpfr_init_set_ui(fugly, 0, GMP_RNDN);
for(i = 0; i < LUNAR_LONGITUDE_ARGS_SIZE; i++) {
mpfr_t a, b, v, w, x, y, z;
mpfr_init_set_d( v, LUNAR_LONGITUDE_ARGS[i][0], GMP_RNDN );
mpfr_init_set_d( w, LUNAR_LONGITUDE_ARGS[i][1], GMP_RNDN );
mpfr_init_set_d( x, LUNAR_LONGITUDE_ARGS[i][2], GMP_RNDN );
mpfr_init_set_d( y, LUNAR_LONGITUDE_ARGS[i][3], GMP_RNDN );
mpfr_init_set_d( z, LUNAR_LONGITUDE_ARGS[i][4], GMP_RNDN );
mpfr_init(b);
mpfr_pow(b, E, x, GMP_RNDN);
mpfr_mul(w, w, elongation, GMP_RNDN);
mpfr_mul(x, x, solar_anomaly, GMP_RNDN);
mpfr_mul(y, y, lunar_anomaly, GMP_RNDN);
mpfr_mul(z, z, moon_node, GMP_RNDN);
mpfr_init_set(a, w, GMP_RNDN);
mpfr_add(a, a, x, GMP_RNDN);
mpfr_add(a, a, y, GMP_RNDN);
mpfr_add(a, a, z, GMP_RNDN);
dt_astro_sin(&a, &a);
mpfr_mul(a, a, v, GMP_RNDN);
mpfr_mul(a, a, b, GMP_RNDN);
mpfr_add(fugly, fugly, a, GMP_RNDN);
mpfr_clear(a);
mpfr_clear(b);
mpfr_clear(v);
mpfr_clear(w);
mpfr_clear(x);
mpfr_clear(y);
mpfr_clear(z);
}
mpfr_init_set_d( correction, 0.000001, GMP_RNDN );
mpfr_mul( correction, correction, fugly, GMP_RNDN);
mpfr_clear(fugly);
}
{
mpfr_t a, b;
mpfr_init(venus);
mpfr_init_set_d(a, 119.75, GMP_RNDN);
mpfr_init_set(b, C, GMP_RNDN);
mpfr_mul_d(b, b, 131.849, GMP_RNDN);
mpfr_add(a, a, b, GMP_RNDN);
dt_astro_sin(&a, &a);
mpfr_mul_d(venus, a, 0.003957, GMP_RNDN );
mpfr_clear(a);
mpfr_clear(b);
}
{
mpfr_t a, b;
mpfr_init(jupiter);
mpfr_init_set_d(a, 53.09, GMP_RNDN);
mpfr_init_set(b, C, GMP_RNDN);
mpfr_mul_d(b, b, 479264.29, GMP_RNDN);
mpfr_add(a, a, b, GMP_RNDN);
dt_astro_sin(&a, &a);
mpfr_mul_d(jupiter, a, 0.000318, GMP_RNDN );
mpfr_clear(a);
mpfr_clear(b);
}
{
mpfr_t a;
mpfr_init(flat_earth);
mpfr_init_set(a, mean_moon, GMP_RNDN);
mpfr_sub(a, a, moon_node, GMP_RNDN);
dt_astro_sin(&a, &a);
mpfr_mul_d(flat_earth, a, 0.001962, GMP_RNDN);
mpfr_clear(a);
}
mpfr_set(*result, mean_moon, GMP_RNDN);
mpfr_add(*result, *result, correction, GMP_RNDN);
mpfr_add(*result, *result, venus, GMP_RNDN);
mpfr_add(*result, *result, jupiter, GMP_RNDN);
mpfr_add(*result, *result, flat_earth, GMP_RNDN);
#ifdef ANNOYING_DEBUG
#if (ANNOYING_DEBUG)
mpfr_fprintf(stderr,
"mean_moon = %.10RNf\ncorrection = %.10RNf\nvenus = %.10RNf\njupiter = %.10RNf\nflat_earth = %.10RNf\n",
mean_moon,
correction,
venus,
jupiter,
flat_earth);
#endif
#endif
mpfr_init(N);
nutation(&N, moment);
mpfr_add(*result, *result, N, GMP_RNDN);
mpfr_init_set_ui(fullangle, 360, GMP_RNDN);
#ifdef ANNOYING_DEBUG
#if (ANNOYING_DEBUG)
mpfr_fprintf(stderr, "lunar = mod(%.10RNf) = ", *result );
#endif
#endif
dt_astro_mod(result, result, &fullangle);
#ifdef ANNOYING_DEBUG
#if (ANNOYING_DEBUG)
mpfr_fprintf(stderr, "%.10RNf\n", *result );
#endif
#endif
mpfr_clear(C);
mpfr_clear(mean_moon);
mpfr_clear(elongation);
mpfr_clear(solar_anomaly);
mpfr_clear(lunar_anomaly);
mpfr_clear(moon_node);
mpfr_clear(E);
mpfr_clear(correction);
mpfr_clear(venus);
mpfr_clear(jupiter);
mpfr_clear(flat_earth);
mpfr_clear(N);
mpfr_clear(fullangle);
return 1;
}
