public static MoonRiseResult CalculateMoonRiseSet(Coordinate coordinate, DateTime time)
{
int zone = TimeZone.CurrentTimeZone.ToUniversalTime(time).Hour; //1; // Math.Round(Now.getTimezoneOffset()/60);
double jd = time.DtToJulianDay(); // -2451545; // Julian day relative to Jan 1.5, 2000
//if ((sgn(zone) == sgn(lon))&&(zone != 0))
// window.alert("WARNING: time zone and longitude are incompatible!");
double[,] mp = new double[3, 3]; // create a 3x3 array
for (int i = 0; i < 3; i++)
{
//mp[i] = new Array(3);
for (int j = 0; j < 3; j++)
{
mp[i, j] = 0.0;
}
}
double lon = coordinate.LongitudeDeg / 360;
var tz = zone / 24;
var t0 = CalculateLocalSiderealTime(lon, jd, tz); // local sidereal time
jd = jd + tz; // get moon position at start of day
for (int k = 0; k < 3; k++)
{
double[] Sky = CalculateMoon(jd);
mp[k, 0] = Sky[0];
mp[k, 1] = Sky[1];
mp[k, 2] = Sky[2];
jd = jd + 0.5;
}
if (mp[1, 0] <= mp[0, 0])
{
mp[1, 0] = mp[1, 0] + 2 * Math.PI;
}
if (mp[2, 0] <= mp[1, 0])
{
mp[2, 0] = mp[2, 0] + 2 * Math.PI;
}
double[] RAn = new double[3];
double[] Dec = new double[3];
double[] VHz = new double[3];
RAn[0] = mp[0, 0];
Dec[0] = mp[0, 1];
//bool Moonrise = false; // initialize
//bool Moonset = false;
List <MoonRiseResult> resultArray = new List <MoonRiseResult>();
for (int k = 0; k < 24; k++) // check each hour of this day
{
double ph = (k + 1) / 24;
RAn[2] = Interpolate3values(mp[0, 0], mp[1, 0], mp[2, 0], ph);
Dec[2] = Interpolate3values(mp[0, 1], mp[1, 1], mp[2, 1], ph);
MoonRiseResult TestMoonHour = test_moon(time, k, zone, t0, coordinate.LatitudeDeg, mp[1, 2]);
resultArray.Add(TestMoonHour);
VHz[2] = TestMoonHour.Vhz;
RAn[0] = RAn[2]; // advance to next hour
Dec[0] = Dec[2];
VHz[0] = VHz[2];
}
MoonRiseResult result = new MoonRiseResult();
foreach (var moonres in resultArray)
{
if (moonres.IsMoonRise)
{
result.IsMoonRise = true;
result.RiseTime = moonres.RiseTime;
result.RiseAz = moonres.RiseAz;
}
if (moonres.IsMoonSet)
{
result.IsMoonSet = true;
result.SetTime = moonres.SetTime;
result.SetAZ = moonres.SetAZ;
}
}
// display results
//calc.moonrise.value = zintstr(Rise_time[0], 2) + ":" + zintstr(Rise_time[1], 2)
// + ", az = " + frealstr(Rise_az, 5, 1) + "°";
//calc.moonset.value = zintstr( Set_time[0], 2) + ":" + zintstr( Set_time[1], 2)
// + ", az = " + frealstr(Set_az, 5, 1) + "°";
return(result);
}
public static MoonRiseResult test_moon(DateTime date,
double k, double zone, double t0, double lat, double plx)
{
MoonRiseResult result = new MoonRiseResult();
double[] ha = new double[3] {
0.0, 0.0, 0.0
};
double a, b, c, d, e, s, z;
double hr, min, time;
double az, hz, nz, dz;
double[] RAn = new double[3];
double[] Dec = new double[3];
double[] VHz = new double[3];
double DR = Math.PI / 180;
double K1 = 15 * DR * 1.0027379;
if (RAn[2] < RAn[0])
{
RAn[2] = RAn[2] + 2 * Math.PI;
}
ha[0] = t0 - RAn[0] + k * K1;
ha[2] = t0 - RAn[2] + k * K1 + K1;
ha[1] = (ha[2] + ha[0]) / 2; // hour angle at half hour
Dec[1] = (Dec[2] + Dec[0]) / 2; // declination at half hour
s = Math.Sin(DR * lat);
c = Math.Cos(DR * lat);
// refraction + sun semidiameter at horizon + parallax correction
z = Math.Cos(DR * (90.567 - 41.685 / plx));
if (k <= 0) // first call of function
{
VHz[0] = s * Math.Sin(Dec[0]) + c * Math.Cos(Dec[0]) * Math.Cos(ha[0]) - z;
}
VHz[2] = s * Math.Sin(Dec[2]) + c * Math.Cos(Dec[2]) * Math.Cos(ha[2]) - z;
if (Math.Sign(VHz[0]) == Math.Sign(VHz[2]))
{
result.Vhz = VHz[2];
return(result); // VHz[2]; // no event this hour
}
VHz[1] = s * Math.Sin(Dec[1]) + c * Math.Cos(Dec[1]) * Math.Cos(ha[1]) - z;
a = 2 * VHz[2] - 4 * VHz[1] + 2 * VHz[0];
b = 4 * VHz[1] - 3 * VHz[0] - VHz[2];
d = b * b - 4 * a * VHz[0];
if (d < 0)
{
result.Vhz = VHz[2];
return(result); // VHz[2]; // no event this hour
}
d = Math.Sqrt(d);
e = (-b + d) / (2 * a);
if ((e > 1) || (e < 0))
{
e = (-b - d) / (2 * a);
}
time = k + e + 1 / 120; // time of an event + round up
hr = Math.Floor(time);
min = Math.Floor((time - hr) * 60);
hz = ha[0] + e * (ha[2] - ha[0]); // azimuth of the moon at the event
nz = -Math.Cos(Dec[1]) * Math.Sin(hz);
dz = c * Math.Sin(Dec[1]) - s * Math.Cos(Dec[1]) * Math.Cos(hz);
az = Math.Atan2(nz, dz) / DR;
if (az < 0)
{
az = az + 360;
}
if ((VHz[0] < 0) && (VHz[2] > 0))
{
result.RiseTime = date.Date.AddHours(hr).AddMinutes(min);
result.RiseAz = az;
result.IsMoonRise = true;
result.Vhz = VHz[2];
//Rise_time[0] = hr;
//Rise_time[1] = min;
//Rise_az = az;
//Moonrise = true;
}
if ((VHz[0] > 0) && (VHz[2] < 0))
{
result.SetTime = date.Date.AddHours(hr).AddMinutes(min);
result.SetAZ = az;
result.IsMoonSet = true;
result.Vhz = VHz[2];
//Set_time[0] = hr;
//Set_time[1] = min;
//Set_az = az;
//Moonset = true;
}
return(result);
}
