picplanner/src/calculations/calculations_sun.c

102 wiersze
3.4 KiB
C

/*
* calculations_sun.c
* Copyright (C) 2021 Zwarf <zwarf@mail.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "calculations_sun.h"
double
*picplanner_get_coordinates_rotational_sun (GDateTime *date_time)
{
double *coordinates_sun = malloc(sizeof (double) * 2);
double right_ascension;
double declination;
double T;
double mean_longitude;
double mean_anomaly;
double equation_of_center;
double ecliptic_longitude;
double ecliptic;
double time_jd;
time_jd = calc_jd (date_time);
T = (time_jd-2451545.0)/36525.;
mean_longitude = 280.46645 + (36000.76983 + 0.0003032*T)*T;
mean_anomaly = 357.52910 + (35999.05030 - (0.0001559 - 0.00000048*T)*T)*T;
equation_of_center = (1.914600 - (0.004817 - 0.000014*T)*T)*sin(calc_deg_to_rad (mean_anomaly))
+ (0.019993 - 0.000101*T)*sin(2*calc_deg_to_rad (mean_anomaly))
+ (0.00029)*sin(3*calc_deg_to_rad (mean_anomaly));
ecliptic_longitude = mean_longitude + equation_of_center;
ecliptic = 23.43928 + 0.01301*T;
ecliptic_longitude = calc_deg_to_rad (ecliptic_longitude);
ecliptic = calc_deg_to_rad (ecliptic);
right_ascension = atan2 (cos(ecliptic)*sin(ecliptic_longitude), cos(ecliptic_longitude));
declination = asin (sin(ecliptic)*sin(ecliptic_longitude));
coordinates_sun[0] = calc_rad_to_deg (right_ascension);
coordinates_sun[1] = calc_rad_to_deg (declination);
return coordinates_sun;
}
double
*picplanner_get_coordinates_sun (GDateTime *date_time,
double longitude,
double latitude)
{
double siderial_time;
g_autofree double *coordinates_sun = NULL;
double *coordinates_horizontal_sun;
coordinates_sun = picplanner_get_coordinates_rotational_sun (date_time);
siderial_time = time_jd_to_sidereal_time (longitude, date_time);
coordinates_horizontal_sun = picplanner_transform_rotational_to_horizontal (coordinates_sun,
latitude,
siderial_time);
return coordinates_horizontal_sun;
}
double
*picplanner_get_array_coordinates_sun (GDateTime *date_time,
double longitude,
double latitude)
{
double *array_coordinates_sun = malloc (sizeof (double) * 2 * NUM_DATA_POINTS);
for (int i=0; i<NUM_DATA_POINTS; i++)
{
GDateTime *iteration_time = g_date_time_add_minutes (date_time, i*24*60/NUM_DATA_POINTS-12*60);
g_autofree double *coordinates_sun =
picplanner_get_coordinates_sun (iteration_time,
longitude,
latitude);
array_coordinates_sun[2*i] = coordinates_sun[0];
array_coordinates_sun[2*i+1] = coordinates_sun[1];
}
return array_coordinates_sun;
}