public static TimeSpan GetTimeEquation(DateTime date)
{
double b = 360 * (date.DayOfYear - 81) / 365;
double t = 7.53 * Math.Cos(Astro.Rad(b)) + 1.5 * Math.Sin(Astro.Rad(b)) - 9.87 * Math.Sin(Astro.Rad(2 * b));
return(new TimeSpan(0, (int)t, 0));
}
//return Sine of the altitude
//mJD0h - is Modified Julian Date on 00:00
//hour - is adding hour to 00:00
private double SinAlt(double mJD0h, double hour, double latitude, double longitude)
{
double MJD, T, RA, Declination, tau;
MJD = mJD0h + hour / 24.0;
T = (MJD - 51544.5) / 36525.0;
var v = GetSunCoor(T);
EclipLon = EclipLon == -1 ? v.X : EclipLon;
v = Astro.ToEquatorial(v);
RA = v.X;
Declination = v.Y;
tau = Astro.GMST(MJD) + Astro.Rad(longitude) - RA;
return(Math.Sin(Astro.Rad(latitude)) * Math.Sin(Declination) + Math.Cos(Astro.Rad(latitude)) * Math.Cos(Declination) * Math.Cos(tau));
}
public Sun(DateTime date, double latitude, double longitude, TimeZoneInfo timezone)
{
//Date = new DateTime(date.Year,date.Month,date.Day) + GetTimeEquation(date);
Date = date;
EclipLon = -1;
double[] rises = new double[] { 0, 0, 0, 0 };
double[] sets = new double[] { 0, 0, 0, 0 };
bool[] isrises = new bool[] { false, false, false, false };
bool[] issets = new bool[] { false, false, false, false };
double[] h_correct = new double[]
{
Astro.Rad(-50 / 60.0), Astro.Rad(-6), Astro.Rad(-12), Astro.Rad(-18)
};
double hour = 1.0;
double y_minus, y_0, y_plus;
double xe = 0, ye = 0, root1 = 0, root2 = 0;
int nRoot = 0;
double MJD0h = Astro.Mjd(date) - timezone.GetUtcOffset(date).TotalHours / 24.0;
for (int i = 0; i < 4; i++)
{
hour = 1.0;
y_minus = SinAlt(MJD0h, hour - 1.0, latitude, longitude) - Math.Sin(h_correct[i]);
// loop over search intervals from [0h-2h] to [22h-24h]
do
{
y_0 = SinAlt(MJD0h, hour, latitude, longitude) - Math.Sin(h_correct[i]);
y_plus = SinAlt(MJD0h, hour + 1.0, latitude, longitude) - Math.Sin(h_correct[i]);
// find parabola through three values y_minus,y_0,y_plus
Astro.Quad(y_minus, y_0, y_plus, out xe, out ye, out root1, out root2, out nRoot);
if (nRoot == 1)
{
if (y_minus < 0.0)
{
rises[i] = hour + root1;
isrises[i] = true;
}
else
{
sets[i] = hour + root1;
issets[i] = true;
}
}
if (nRoot == 2)
{
if (ye < 0.0)
{
rises[i] = hour + root2;
sets[i] = hour + root1;
}
else
{
rises[i] = hour + root1;
sets[i] = hour + root2;
}
isrises[i] = true;
issets[i] = true;
}
y_minus = y_plus; // prepare for next interval
hour += 2.0;
}while (!((hour == 25.0) || (isrises[i] && issets[i])));
}
Dawn = Date.AddHours(rises[0]);
Dusk = Date.AddHours(sets[0]);
Noon = Dawn.AddHours((sets[0] - rises[0]) / 2);
if (Dusk.Day != Dawn.Day)
{
Noon = Noon.AddHours(12);
}
CivilDawn = Date.AddHours(rises[1]);
CivilDusk = Date.AddHours(sets[1]);
NauticalDawn = Date.AddHours(rises[2]);
NauticalDusk = Date.AddHours(sets[2]);
AstronomicalDawn = Date.AddHours(rises[3]);
AstronomicalDusk = Date.AddHours(sets[3]);
Result = new SunResult
{
NoDawnDusk = !isrises[0] || !issets[0],
NoCivil = !isrises[1] || !issets[1],
NoNautical = !isrises[2] | !issets[2],
NoAstronomical = !isrises[3] | !issets[3],
};
}
public Moon(DateTime date, double latitude, double longitude, TimeZoneInfo timezone)
{
Date = date;
EclipLon = -1;
double rise = 0, set = 0;
bool isrise = false, isset = false;
double h_correct = Astro.Rad(8 / 60.0);
double hour = 1.0;
double y_minus, y_0, y_plus;
double xe = 0, ye = 0, root1 = 0, root2 = 0;
int nRoot = 0;
double MJD0h = Astro.Mjd(date) - timezone.GetUtcOffset(date).TotalHours / 24.0;
y_minus = SinAlt(MJD0h, hour - 1.0, latitude, longitude) - Math.Sin(h_correct);
// loop over search intervals from [0h-2h] to [22h-24h]
do
{
y_0 = SinAlt(MJD0h, hour, latitude, longitude) - Math.Sin(h_correct);
y_plus = SinAlt(MJD0h, hour + 1.0, latitude, longitude) - Math.Sin(h_correct);
// find parabola through three values y_minus,y_0,y_plus
Astro.Quad(y_minus, y_0, y_plus, out xe, out ye, out root1, out root2, out nRoot);
if (nRoot == 1)
{
if (y_minus < 0.0)
{
rise = hour + root1;
isrise = true;
}
else
{
set = hour + root1;
isset = true;
}
}
if (nRoot == 2)
{
if (ye < 0.0)
{
rise = hour + root2;
set = hour + root1;
}
else
{
rise = hour + root1;
set = hour + root2;
}
isrise = true;
isset = true;
}
y_minus = y_plus; // prepare for next interval
hour += 2.0;
}while (!((hour == 25.0) || (isrise && isset)));
Dawn = Date.AddHours(rise);
Dusk = Date.AddHours(set);
Result = new MoonResult {
NoDawn = !isrise, NoDusk = !isset
};
var v = GetMoonDay(Date);
}