public double DailyIncomingRadiationIntensity(double lat, double lng, DateTime day, double cloudcover = 0.1)
{
mSunEarth.Latitude = lat;
mSunEarth.Longitude = lng;
int hours = 24;
double[] radis = new double[hours];
for (int i = 0; i < hours; i++)
{
DateTime dt = day.AddHours(i);
SunCoordinates sc = mSunEarth.SunPostion(dt);
if (sc.Azimuth > 0)
{
radis[i] = 1366.2 * Math.Sin(sc.Azimuth * SunEarth.D2R) * (1 - 0.71 * cloudcover) * SkyAttenuation * 3600;
}
}
return(radis.Sum());
}
public double[] HourlyIncomingRadiationIntensity(DateTime start, DateTime end, double cloudcover)
{
SunEarth se = new SunEarth(Latitude, Longitude);
TimeSpan ts = end - start;
int hours = (int)ts.TotalHours;
double[] radis = new double[hours];
for (int i = 0; i < hours; i++)
{
DateTime dt = start.AddHours(i);
SunCoordinates sc = se.SunPostion(dt);
if (sc.Azimuth > 0)
{
radis[i] = 1366.2 * Math.Sin(sc.Azimuth * SunEarth.D2R) * (1 - 0.71 * cloudcover) * SkyAttenuation;
}
}
return(radis);
}
/// <summary>
/// the Altitude angular height of the sun in the sky measured from the horizontal.
/// </summary>
/// <param name="lat"></param>
/// <param name="lng"></param>
/// <param name="time"></param>
/// <returns>Solar atitude in degree</returns>
public SunCoordinates SunPostion(DateTime time)
{
SunCoordinates sc = new SunCoordinates();
double latR = Latitude * D2R;
double lngR = Longitude * D2R;
double declination = DeclinationAngle(time.DayOfYear);
double lst = LST(Longitude, time);
double hra = HRA(lst);
double ele = Math.Sin(latR) * Math.Sin(declination) + Math.Cos(latR) * Math.Cos(declination) * Math.Cos(hra * D2R);
double eleR = Math.Asin(ele);
sc.Azimuth = eleR * R2D;
double azi = (Math.Sin(declination) * Math.Cos(latR) - Math.Cos(declination) * Math.Sin(latR) * Math.Cos(hra * D2R)) / Math.Cos(eleR);
sc.ZenithAngle = Math.Acos(azi) * R2D;
//if (hra > 0 || lst > 0)
// sc.ZenithAngle = 360 - sc.ZenithAngle;
return(sc);
}
public double[] HourlyIncomingRadiationIntensity(DateTime start, DateTime end, double[] cloudcovers)
{
SunEarth se = new SunEarth(Latitude, Longitude);
TimeSpan ts = end - start;
int hours = (int)ts.TotalHours;
double[] radis = new double[hours];
if (cloudcovers.Length != hours)
{
throw new Exception("The number of cloud-cover values does not match with the hours");
}
for (int i = 0; i < hours; i++)
{
DateTime dt = start.AddHours(i);
SunCoordinates sc = se.SunPostion(dt);
if (sc.Azimuth > 0)
{
radis[i] = 1366.2 * Math.Sin(sc.Azimuth * SunEarth.D2R) * (1 - 0.71 * cloudcovers[i]) * SkyAttenuation;
}
}
return(radis);
}
public SunCoordinates SunPostion(SolarTime udtTime, Location udtLocation)
{
SunCoordinates udtSunCoordinates = new SunCoordinates();
// Main variables
double dElapsedJulianDays;
double dDecimalHours;
double dEclipticLongitude;
double dEclipticObliquity;
double dRightAscension;
double dDeclination;
// Auxiliary variables
double dY;
double dX;
// Calculate difference in days between the current Julian Day
// and JD 2451545.0, which is noon 1 January 2000 Universal Time
double dJulianDate;
long liAux1;
long liAux2;
// Calculate time of the day in UT decimal hours
dDecimalHours = udtTime.dHours + (udtTime.dMinutes
+ udtTime.dSeconds / 60.0) / 60.0;
// Calculate current Julian Day
liAux1 = (udtTime.iMonth - 14) / 12;
liAux2 = (1461 * (udtTime.iYear + 4800 + liAux1)) / 4 + (367 * (udtTime.iMonth
- 2 - 12 * liAux1)) / 12 - (3 * ((udtTime.iYear + 4900
+ liAux1) / 100)) / 4 + udtTime.iDay - 32075;
dJulianDate = (double)(liAux2) - 0.5 + dDecimalHours / 24.0;
// Calculate difference between current Julian Day and JD 2451545.0
dElapsedJulianDays = dJulianDate - 2451545.0;
// Calculate ecliptic coordinates (ecliptic longitude and obliquity of the
// ecliptic in radians but without limiting the angle to be less than 2*Pi
// (i.e., the result may be greater than 2*Pi)
double dMeanLongitude;
double dMeanAnomaly;
double dOmega;
dOmega = 2.1429 - 0.0010394594 * dElapsedJulianDays;
dMeanLongitude = 4.8950630 + 0.017202791698 * dElapsedJulianDays; // Radians
dMeanAnomaly = 6.2400600 + 0.0172019699 * dElapsedJulianDays;
dEclipticLongitude = dMeanLongitude + 0.03341607 * Math.Sin(dMeanAnomaly)
+ 0.00034894 * Math.Sin(2 * dMeanAnomaly) - 0.0001134
- 0.0000203 * Math.Sin(dOmega);
dEclipticObliquity = 0.4090928 - 6.2140e-9 * dElapsedJulianDays
+ 0.0000396 * Math.Cos(dOmega);
// Calculate celestial coordinates ( right ascension and declination ) in radians
// but without limiting the angle to be less than 2*Pi (i.e., the result may be
// greater than 2*Pi)
double dSin_EclipticLongitude;
dSin_EclipticLongitude = Math.Sin(dEclipticLongitude);
dY = Math.Cos(dEclipticObliquity) * dSin_EclipticLongitude;
dX = Math.Cos(dEclipticLongitude);
dRightAscension = Math.Atan2(dY, dX);
if (dRightAscension < 0.0)
{
dRightAscension = dRightAscension + twopi;
}
dDeclination = Math.Asin(Math.Sin(dEclipticObliquity) * dSin_EclipticLongitude);
// Calculate local coordinates ( azimuth and zenith angle ) in degrees
double dGreenwichMeanSiderealTime;
double dLocalMeanSiderealTime;
double dLatitudeInRadians;
double dHourAngle;
double dCos_Latitude;
double dSin_Latitude;
double dCos_HourAngle;
double dParallax;
dGreenwichMeanSiderealTime = 6.6974243242 +
0.0657098283 * dElapsedJulianDays
+ dDecimalHours;
dLocalMeanSiderealTime = (dGreenwichMeanSiderealTime * 15
+ udtLocation.dLongitude) * rad;
dHourAngle = dLocalMeanSiderealTime - dRightAscension;
dLatitudeInRadians = udtLocation.dLatitude * rad;
dCos_Latitude = Math.Cos(dLatitudeInRadians);
dSin_Latitude = Math.Sin(dLatitudeInRadians);
dCos_HourAngle = Math.Cos(dHourAngle);
udtSunCoordinates.ZenithAngle = (Math.Acos(dCos_Latitude * dCos_HourAngle
* Math.Cos(dDeclination) + Math.Sin(dDeclination) * dSin_Latitude));
dY = -Math.Sin(dHourAngle);
dX = Math.Tan(dDeclination) * dCos_Latitude - dSin_Latitude * dCos_HourAngle;
udtSunCoordinates.Azimuth = Math.Atan2(dY, dX);
if (udtSunCoordinates.Azimuth < 0.0)
{
udtSunCoordinates.Azimuth = udtSunCoordinates.Azimuth + twopi;
}
udtSunCoordinates.Azimuth = udtSunCoordinates.Azimuth / rad;
// Parallax Correction
dParallax = (dEarthMeanRadius / dAstronomicalUnit)
* Math.Sin(udtSunCoordinates.ZenithAngle);
udtSunCoordinates.ZenithAngle = (udtSunCoordinates.ZenithAngle + dParallax) / rad;
return(udtSunCoordinates);
}
