///////////////////////////////////////////////////////////////////////////////////////////
// Calculate all SPA parameters and put into structure
// Note: All inputs values (listed in header file) must already be in structure
///////////////////////////////////////////////////////////////////////////////////////////
#region Calculate all SPA parameters and put into structure
public int spa_calculate(ref SpaData spa)
{
int result;
result = validate_inputs(ref spa);
if (result == 0)
{
spa.Jd = julian_day(spa.Year, spa.Month, spa.Day,
spa.Hour, spa.Minute, spa.Second, spa.Timezone);
calculate_geocentric_sun_right_ascension_and_declination(ref spa);
spa.H = observer_hour_angle(spa.Nu, spa.Longitude, spa.Alpha);
spa.Xi = sun_equatorial_horizontal_parallax(spa.R);
sun_right_ascension_parallax_and_topocentric_dec(spa.Latitude, spa.Elevation, spa.Xi,
spa.H, spa.Delta, ref spa.DelAlpha, ref spa.DeltaPrime);
spa.AlphaPrime = topocentric_sun_right_ascension(spa.Alpha, spa.DelAlpha);
spa.HPrime = topocentric_local_hour_angle(spa.H, spa.DelAlpha);
spa.E0 = topocentric_elevation_angle(spa.Latitude, spa.DeltaPrime, spa.HPrime);
spa.DelE = atmospheric_refraction_correction(spa.Pressure, spa.Temperature,
spa.AtmosRefract, spa.E0);
spa.E = topocentric_elevation_angle_corrected(spa.E0, spa.DelE);
spa.Zenith = topocentric_zenith_angle(spa.E);
spa.Azimuth180 = topocentric_azimuth_angle_neg180_180(spa.HPrime, spa.Latitude,
spa.DeltaPrime);
spa.Azimuth = topocentric_azimuth_angle_zero_360(spa.Azimuth180);
if ((spa.Function == (int)SpaSelect.SpaZaInc) || (spa.Function == (int)SpaSelect.SpaAll))
{
spa.Incidence = surface_incidence_angle(spa.Zenith, spa.Azimuth180,
spa.AzmRotation, spa.Slope);
}
if ((spa.Function == (int)SpaSelect.SpaZaRts) || (spa.Function == (int)SpaSelect.SpaAll))
{
calculate_eot_and_sun_rise_transit_set(ref spa);
}
}
return(result);
}
////////////////////////////////////////////////////////////////////////////////////////////////
// Calculate required SPA parameters to get the right ascension (alpha) and declination (delta)
// Note: JD must be already calculated and in structure
////////////////////////////////////////////////////////////////////////////////////////////////
#region SPA
public void calculate_geocentric_sun_right_ascension_and_declination(ref SpaData spa)
{
double[] x = new double[(int)TermX.TermXCount];
spa.Jc = julian_century(spa.Jd);
spa.Jde = julian_ephemeris_day(spa.Jd, spa.DeltaT);
spa.Jce = julian_ephemeris_century(spa.Jde);
spa.Jme = julian_ephemeris_millennium(spa.Jce);
spa.L = earth_heliocentric_longitude(spa.Jme);
spa.B = earth_heliocentric_latitude(spa.Jme);
spa.R = earth_radius_vector(spa.Jme);
spa.Theta = geocentric_longitude(spa.L);
spa.Beta = geocentric_latitude(spa.B);
x[(int)TermX.TermX0] = spa.X0 = mean_elongation_moon_sun(spa.Jce);
x[(int)TermX.TermX1] = spa.X1 = mean_anomaly_sun(spa.Jce);
x[(int)TermX.TermX2] = spa.X2 = mean_anomaly_moon(spa.Jce);
x[(int)TermX.TermX3] = spa.X3 = argument_latitude_moon(spa.Jce);
x[(int)TermX.TermX4] = spa.X4 = ascending_longitude_moon(spa.Jce);
nutation_longitude_and_obliquity(spa.Jce, x, ref spa.DelPsi, ref spa.DelEpsilon);
spa.Epsilon0 = ecliptic_mean_obliquity(spa.Jme);
spa.Epsilon = ecliptic_true_obliquity(spa.DelEpsilon, spa.Epsilon0);
spa.DelTau = aberration_correction(spa.R);
spa.Lamda = apparent_sun_longitude(spa.Theta, spa.DelPsi, spa.DelTau);
spa.Nu0 = greenwich_mean_sidereal_time(spa.Jd, spa.Jc);
spa.Nu = greenwich_sidereal_time(spa.Nu0, spa.DelPsi, spa.Epsilon);
spa.Alpha = geocentric_sun_right_ascension(spa.Lamda, spa.Epsilon, spa.Beta);
spa.Delta = geocentric_sun_declination(spa.Beta, spa.Epsilon, spa.Lamda);
}
///////////////////////////////////////////////////////////////////////////////////////////////
public int validate_inputs(ref SpaData spa)
{
if ((spa.Year < -2000) || (spa.Year > 6000))
{
return(1);
}
if ((spa.Month < 1) || (spa.Month > 12))
{
return(2);
}
if ((spa.Day < 1) || (spa.Day > 31))
{
return(3);
}
if ((spa.Hour < 0) || (spa.Hour > 24))
{
return(4);
}
if ((spa.Minute < 0) || (spa.Minute > 59))
{
return(5);
}
if ((spa.Second < 0) || (spa.Second > 59))
{
return(6);
}
if ((spa.Pressure < 0) || (spa.Pressure > 5000))
{
return(12);
}
if ((spa.Temperature <= -273) || (spa.Temperature > 6000))
{
return(13);
}
if ((spa.Hour == 24) && (spa.Minute > 0))
{
return(5);
}
if ((spa.Hour == 24) && (spa.Second > 0))
{
return(6);
}
if (Math.Abs(spa.DeltaT) > 8000)
{
return(7);
}
if (Math.Abs(spa.Timezone) > 18)
{
return(8);
}
if (Math.Abs(spa.Longitude) > 180)
{
return(9);
}
if (Math.Abs(spa.Latitude) > 90)
{
return(10);
}
if (Math.Abs(spa.AtmosRefract) > 5)
{
return(16);
}
if (spa.Elevation < -6500000)
{
return(11);
}
if ((spa.Function == (int)SpaSelect.SpaZaInc) || (spa.Function == (int)SpaSelect.SpaAll))
{
if (Math.Abs(spa.Slope) > 360)
{
return(14);
}
if (Math.Abs(spa.AzmRotation) > 360)
{
return(15);
}
}
return(0);
}
public Spa()
{
spa = new SpaData();
}
////////////////////////////////////////////////////////////////////////
// Calculate Equation of Time (EOT) and Sun Rise, Transit, & Set (RTS)
////////////////////////////////////////////////////////////////////////
#region Calculate Equation of Time (EOT) and Sun Rise, Transit, & Set (RTS)
private void calculate_eot_and_sun_rise_transit_set(ref SpaData spa)
{
SpaData sunRts;
double nu, m, h0, n;
double[] alpha = new double[(int)Julian.JdCount];
double[] delta = new double[(int)Julian.JdCount];
double[] mRts = new double[(int)SunTerm.SunCount];
double[] nuRts = new double[(int)SunTerm.SunCount];
double[] hRts = new double[(int)SunTerm.SunCount];
double[] alphaPrime = new double[(int)SunTerm.SunCount];
double[] deltaPrime = new double[(int)SunTerm.SunCount];
double[] hPrime = new double[(int)SunTerm.SunCount];
double h0Prime = -1 * (SunRadius + spa.AtmosRefract);
int i;
sunRts = spa;
m = sun_mean_longitude(spa.Jme);
spa.Eot = Eot(m, spa.Alpha, spa.DelPsi, spa.Epsilon);
sunRts.Hour = sunRts.Minute = sunRts.Second = 0;
sunRts.Timezone = 0.0;
sunRts.Jd = julian_day(sunRts.Year, sunRts.Month, sunRts.Day,
sunRts.Hour, sunRts.Minute, sunRts.Second, sunRts.Timezone);
calculate_geocentric_sun_right_ascension_and_declination(ref sunRts);
nu = sunRts.Nu;
sunRts.DeltaT = 0;
sunRts.Jd--;
for (i = 0; i < (int)Julian.JdCount; i++)
{
calculate_geocentric_sun_right_ascension_and_declination(ref sunRts);
alpha[i] = sunRts.Alpha;
delta[i] = sunRts.Delta;
sunRts.Jd++;
}
mRts[(int)SunTerm.SunTransit] = approx_sun_transit_time(alpha[(int)Julian.JdZero], spa.Longitude, nu);
h0 = sun_hour_angle_at_rise_set(spa.Latitude, delta[(int)Julian.JdZero], h0Prime);
if (h0 >= 0)
{
approx_sun_rise_and_set(ref mRts, h0);
for (i = 0; i < (int)SunTerm.SunCount; i++)
{
nuRts[i] = nu + 360.985647 * mRts[i];
n = mRts[i] + spa.DeltaT / 86400.0;
alphaPrime[i] = rts_alpha_delta_prime(ref alpha, n);
deltaPrime[i] = rts_alpha_delta_prime(ref delta, n);
hPrime[i] = limit_degrees180pm(nuRts[i] + spa.Longitude - alphaPrime[i]);
hRts[i] = rts_sun_altitude(spa.Latitude, deltaPrime[i], hPrime[i]);
}
spa.Srha = hPrime[(int)SunTerm.SunRise];
spa.Ssha = hPrime[(int)SunTerm.SunSet];
spa.Sta = hRts[(int)SunTerm.SunTransit];
spa.Suntransit = dayfrac_to_local_hr(mRts[(int)SunTerm.SunTransit] - hPrime[(int)SunTerm.SunTransit] / 360.0,
spa.Timezone);
spa.Sunrise = dayfrac_to_local_hr(sun_rise_and_set(ref mRts, ref hRts, ref deltaPrime,
spa.Latitude, ref hPrime, h0Prime, (int)SunTerm.SunRise), spa.Timezone);
spa.Sunset = dayfrac_to_local_hr(sun_rise_and_set(ref mRts, ref hRts, ref deltaPrime,
spa.Latitude, ref hPrime, h0Prime, (int)SunTerm.SunSet), spa.Timezone);
}
else
{
spa.Srha = spa.Ssha = spa.Sta = spa.Suntransit = spa.Sunrise = spa.Sunset = -99999;
}
}