public static GCHourTime CalcSunrise(GregorianDateTime vct, GCEarthData earth)
{
double tempSunrise = 180.0;
GCSunData sun = new GCSunData();
for (int i = 0; i < 3; i++)
{
sun.SunPosition(vct, earth, tempSunrise - 180.0);
double x;
// definition of event
double eventdef = 0.01454;
/* switch(ed.obs)
* {
* case 1: // civil twilight
* eventdef = 0.10453;
* break;
* case 2: // nautical twilight
* eventdef = 0.20791;
* break;
* case 3: // astronomical twilight
* eventdef = 0.30902;
* break;
* default:// center of the sun on the horizont
* eventdef = 0.01454;
* break;
* }*/
eventdef = (eventdef / GCMath.cosDeg(earth.latitudeDeg)) / GCMath.cosDeg(sun.declinationDeg);
x = GCMath.tanDeg(earth.latitudeDeg) * GCMath.tanDeg(sun.declinationDeg) + eventdef;
if ((x >= -1.0) && (x <= 1.0))
{
// time of sunrise
tempSunrise = 90.0 - earth.longitudeDeg - GCMath.arcSinDeg(x) + sun.equationOfTime;
}
else
{
// initial values for the case
// that no rise no set for that day
tempSunrise = -360.0;
break;
}
}
GCHourTime result = new GCHourTime();
result.longitude = sun.longitudeDeg;
result.SetDegTime(tempSunrise + earth.OffsetUtcHours * 15.0);
return(result);
}
public static GCHourTime CalcSunset(GregorianDateTime vct, GCEarthData earth)
{
double tempSunset = 180.0;
GCSunData sun = new GCSunData();
for (int i = 0; i < 3; i++)
{
sun.SunPosition(vct, earth, tempSunset - 180.0);
double x;
// definition of event
double eventdef = GCSunData.RiseAngleLevel;
eventdef = (eventdef / GCMath.cosDeg(earth.latitudeDeg)) / GCMath.cosDeg(sun.declinationDeg);
x = GCMath.tanDeg(earth.latitudeDeg) * GCMath.tanDeg(sun.declinationDeg) + eventdef;
if ((x >= -1.0) && (x <= 1.0))
{
// time of sunset
tempSunset = 270.0 - earth.longitudeDeg + GCMath.arcSinDeg(x) + sun.equationOfTime;
}
else
{
// initial values for the case
// that no rise no set for that day
tempSunset = -360.0;
break;
}
}
GCHourTime result = new GCHourTime();
result.longitude = sun.longitudeDeg;
result.SetDegTime(tempSunset + earth.OffsetUtcHours * 15.0);
return(result);
}
