public AltAz getMoonPosition(long date, double lat, double lng)
{
double lw = rad * -lng,
phi = rad * lat,
d = toDays(date);
RaDec c = moonCoords(d);
double H = siderealTime(d, lw) - c.RA,
h = altitude(H, phi, c.Dec),
// formula 14.1 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
pa = Math.Atan2(Math.Sin(H), Math.Tan(phi) * Math.Cos(c.Dec) - Math.Sin(c.Dec) * Math.Cos(H));
double refraction = astroRefraction(h);
h = h + refraction; // altitude correction for refraction
refraction = refraction / rad;
///HACK HACK magic offsets .76 and .985 determined empirically
///
return(new AltAz()
{
Az = azimuth(H, phi, c.Dec) * dar + 180.0 - 0.76,
Alt = h * dar - 0.985,
distance = c.distance,
paralacticAngle = pa
});
}
/// <summary>
/// </summary>
/// <param name="Alt">The Altitude (90-elevation) in decimal degrees</param>
/// <param name="Az">The Azimuth in decimal degrees</param>
/// <param name="Lat">The latitude in decimal degrees</param>
/// <param name="Long">The longitude in decimal value</param>
/// <param name="Date">The date(time) in UTC</param>
/// <returns>The Right Ascentsion and Decination decimal value</returns>
public static RaDec CalcualteRaDec(double Alt, double Az, double Lat, double Long, DateTime Date)
{
double temp, sin_dec, lat = Lat * (Math.PI / 180);
double cos_lat = Math.Cos(lat);
double alt, az, dec, ha, ra;
alt = Alt * (Math.PI / 180);
az = Az * (Math.PI / 180);
if (alt > Math.PI / 2.0)
{
alt = Math.PI - alt;
az += Math.PI;
}
if (alt < -Math.PI / 2.0)
{
alt = -Math.PI - alt;
az -= Math.PI;
}
sin_dec = Math.Sin(lat) * Math.Sin(alt) + cos_lat * Math.Cos(alt) * Math.Cos(az);
dec = Math.Asin(sin_dec);
if (cos_lat < .00001) /* polar case */
{
ha = az + Math.PI;
}
else
{
temp = cos_lat * Math.Cos(dec);
temp = (Math.Sin(alt) - Math.Sin(lat) * sin_dec) / temp;
if (temp > 1.0)
{
temp = 1.0;
}
temp = Math.Acos(-temp);
///THIS WAS BACKWARDS!
if (Math.Sin(az) < 0.0)
{
ha = Math.PI - temp;
}
else
{
ha = Math.PI + temp;
}
}
double dayOffset = (Date - new DateTime(2000, 1, 1, 12, 0, 0, DateTimeKind.Utc)).TotalDays;
double LST = (100.46 + 0.985647 * dayOffset + Long + 15 * (Date.Hour + Date.Minute / 60d) + 360) % 360;
ra = (LST - (ha * 180.0 / Math.PI) + 360) % 360;
RaDec rd = new RaDec()
{
RA = ra * 24 / 360,
Dec = dec * 180.0 / Math.PI
};
rd.Normalize();
return(rd);
}
// calculates sun position for a given date and latitude/longitude
public AltAz getPosition(int date, double lat, double lng)
{
double lw = rad * -lng,
phi = rad * lat,
d = toDays(date);
RaDec c = sunCoords(d);
double H = siderealTime(d, lw) - c.RA;
return(new AltAz()
{
Az = azimuth(H, phi, c.Dec) * dar + 180.0,
Alt = altitude(H, phi, c.Dec) * dar
});
}
// calculations for illumination parameters of the moon,
// based on http://idlastro.gsfc.nasa.gov/ftp/pro/astro/mphase.pro formulas and
// Chapter 48 of "Astronomical Algorithms" 2nd edition by Jean Meeus (Willmann-Bell, Richmond) 1998.
public illumination getMoonIllumination(long date)
{
double d = toDays(date);
RaDec s = sunCoords(d),
m = moonCoords(d);
double sdist = 149598000, // distance from Earth to Sun in km
phi = Math.Acos(Math.Sin(s.Dec) * Math.Sin(m.Dec) + Math.Cos(s.Dec) * Math.Cos(m.Dec) * Math.Cos(s.RA - m.RA)),
inc = Math.Atan2(sdist * Math.Sin(phi), m.distance - sdist * Math.Cos(phi)),
angle = Math.Atan2(Math.Cos(s.Dec) * Math.Sin(s.RA - m.RA), Math.Sin(s.Dec) * Math.Cos(m.Dec) -
Math.Cos(s.Dec) * Math.Sin(m.Dec) * Math.Cos(s.RA - m.RA));
return(new illumination()
{
fraction = (1 + Math.Cos(inc)) / 2,
phase = 0.5 + 0.5 * inc * (angle < 0 ? -1 : 1) / Math.PI,
angle = angle
});
}
private void presetSelector_SelectedIndexChanged(object sender, EventArgs e)
{
int item = presetSelector.SelectedIndex;
if (item != 0)
{
this.azCommand = this.Presets[item].Az;
this.elCommand = this.Presets[item].El;
GeoAngle mAzAngle = GeoAngle.FromDouble(azCommand, true);
GeoAngle mElAngle = GeoAngle.FromDouble(elCommand);
this.commandAz.Text = string.Format("{0} : {1}", mAzAngle.Degrees, mAzAngle.Minutes);
this.commandEl.Text = string.Format("{0} : {1}", mElAngle.Degrees, mElAngle.Minutes);
RaDec astro = celestialConversion.CalcualteRaDec(mElAngle.ToDouble(), mAzAngle.ToDouble(), settings.latitude, settings.longitude);
GeoAngle Dec = GeoAngle.FromDouble(astro.Dec);
GeoAngle RA = GeoAngle.FromDouble(astro.RA, true);
this.commandRA.Text = string.Format("{0:D3} : {1:D2}", RA.Degrees, RA.Minutes);
this.commandDec.Text = string.Format("{0:D2} : {1:D2}", Dec.Degrees, Dec.Minutes);
}
}
private void SouthPark_Click(object sender, EventArgs e)
{
azCommand = settings.azSouthPark;
elCommand = settings.elSouthPark;
GeoAngle mAzAngle = GeoAngle.FromDouble(azCommand, true);
GeoAngle mElAngle = GeoAngle.FromDouble(elCommand);
this.commandAz.Text = string.Format("{0} : {1}", mAzAngle.Degrees, mAzAngle.Minutes);
this.commandEl.Text = string.Format("{0} : {1}", mElAngle.Degrees, mElAngle.Minutes);
RaDec astro = celestialConversion.CalcualteRaDec(mElAngle.ToDouble(), mAzAngle.ToDouble(), settings.latitude, settings.longitude);
GeoAngle Dec = GeoAngle.FromDouble(astro.Dec);
GeoAngle RA = GeoAngle.FromDouble(astro.RA, true);
this.commandRA.Text = string.Format("{0:D3} : {1:D2}", RA.Degrees, RA.Minutes);
this.commandDec.Text = string.Format("{0:D2} : {1:D2}", Dec.Degrees, Dec.Minutes);
this.state = DishState.Parking;;
azPid.Enable();
elPid.Enable();
}
//update position display
private void updatePosition()
{
if ((DateTime.Now - messageTime).TotalSeconds > 30)
{
Message.Text = "";
}
//read actual form encoders
//if (dev.Connected && state == DishState.Stopped)
//{
// azPos = azReadPosition();
// elPos = elReadPosition();
//}
//set up display variables in deg, min, sec format
GeoAngle AzAngle = GeoAngle.FromDouble(azPos, true);
GeoAngle ElAngle = GeoAngle.FromDouble(elPos);
//convert to RA/DEC
RaDec astro = celestialConversion.CalcualteRaDec(elPos, azPos, settings.latitude, settings.longitude);
//set up RA DEC as deg,min,sec
GeoAngle Dec = GeoAngle.FromDouble(astro.Dec);
GeoAngle RA = GeoAngle.FromDouble(astro.RA, true);
//log position every tenth time through
string posLog = string.Format("RA {0:D3} : {1:D2}\t DEC {2:D3} : {3:D2}", RA.Degrees, RA.Minutes, Dec.Degrees, Dec.Minutes);
currentIncrement++;
if (currentIncrement % 9 == 0)
{
RollingLogger.LogMessage(posLog);
currentIncrement = 0;
}
//show AZ, EL on main form
this.Azimuth.Text = string.Format("{0:D3} : {1:D2}", AzAngle.Degrees, AzAngle.Minutes);
this.Elevation.Text = string.Format("{0:D2} : {1:D2}", ElAngle.Degrees, ElAngle.Minutes);
//show RA,DEC on main form
this.RA.Text = string.Format("{0:D3} : {1:D2}", RA.Degrees, RA.Minutes);
this.DEC.Text = string.Format("{0:D2} : {1:D2}", Dec.Degrees, Dec.Minutes);
//if celestial track is set, check to make sure command position is above horizon if so then enable motion
//probably have to have a completely seperate velocity track loop here - PID loop may not be satisfactor
//-----NEEDS TESTING
if (trackCelestial)
{
AltAz aa = celestialConversion.CalculateAltAz(RAcommand, decCommand, settings.latitude, settings.longitude);
if (aa.Alt < 0)
{
Message.Text = "Requested position is below horizon!";
trackMoon = false;
messageTime = DateTime.Now;
trackCelestial = false;
}
GeoAngle cAzAngle = GeoAngle.FromDouble(aa.Az, true);
GeoAngle cElAngle = GeoAngle.FromDouble(aa.Alt);
azCommand = aa.Az;
elCommand = aa.Alt;
this.commandAz.Text = string.Format("{0:D3} : {1:D2}", cAzAngle.Degrees, cAzAngle.Minutes);
this.commandEl.Text = string.Format("{0:D2} : {1:D2}", cElAngle.Degrees, cElAngle.Minutes);
if (state != DishState.Moving && state != DishState.Tracking && aa.Alt > 1.0)
{
this.Go();
}
}
//if Lunar track is set, check to make sure Moon position is above horizon if so then enable motion
//probably have to have a completely seperate velocity track loop here - PID loop may not be satisfactor
//-----NEEDS TESTING
if (trackMoon)
{
SunCalc sc = new SunCalc();
long eDate = sc.epochDate(DateTime.UtcNow);
double jdate = sc.toJulian(eDate);
AltAz aa = sc.getMoonPosition(eDate, settings.latitude, settings.longitude);
if (aa.Alt < 0)
{
Message.Text = "Moon is below horizon!";
trackMoon = false;
messageTime = DateTime.Now;
}
moonRiseSet mrs = sc.getMoonTimes(eDate, settings.latitude, settings.longitude, true);
azCommand = aa.Az;
elCommand = aa.Alt;
GeoAngle mAzAngle = GeoAngle.FromDouble(aa.Az, true);
GeoAngle mElAngle = GeoAngle.FromDouble(aa.Alt);
this.commandAz.Text = string.Format("{0} : {1}", mAzAngle.Degrees, mAzAngle.Minutes);
this.commandEl.Text = string.Format("{2}{0} : {1}", mElAngle.Degrees, mElAngle.Minutes, mElAngle.IsNegative ? "-" : "");
double Alt = elCommand;
if (Alt > 90.0)
{
Alt = Alt - 90.0;
}
RaDec mastro = celestialConversion.CalcualteRaDec(Alt, azCommand, settings.latitude, settings.longitude);
GeoAngle mDec = GeoAngle.FromDouble(mastro.Dec);
GeoAngle mRA = GeoAngle.FromDouble(mastro.RA, true);
this.commandRA.Text = string.Format("{0:D3} : {1:D2}", mRA.Degrees, mRA.Minutes);
this.commandDec.Text = string.Format("{0:D2} : {1:D2}", mDec.Degrees, mDec.Minutes);
if (state != DishState.Moving && state != DishState.Tracking && aa.Alt > 1.0)
{
this.Go();
}
}//trackMoon
//send stop command if we have to here
if (state != DishState.Stopped && state != DishState.Unknown)
{
if (azPid.Complete && elPid.Complete)
{
this.Stop();
}
}
}
