public override void Calculate(SkyContext context)
{
var p = Precession.ElementsFK5(Date.EPOCH_J2000, context.JulianDay);
foreach (var b in ConstBorders)
{
foreach (var bp in b)
{
// Equatorial coordinates for the mean equinox and epoch of the target date
var eq = Precession.GetEquatorialCoordinates(bp.Equatorial0, p);
// Apparent horizontal coordinates
bp.Horizontal = eq.ToHorizontal(context.GeoLocation, context.SiderealTime);
}
}
foreach (var c in ConstLabels)
{
// Equatorial coordinates for the mean equinox and epoch of the target date
var eq = Precession.GetEquatorialCoordinates(c.Equatorial0, p);
// Apparent horizontal coordinates
c.Horizontal = eq.ToHorizontal(context.GeoLocation, context.SiderealTime);
}
}
/// <summary>
/// Gets equatorial coordinates of a star for current epoch
/// </summary>
public CrdsEquatorial Equatorial(SkyContext c, ushort hrNumber)
{
Star star = Stars.ElementAt(hrNumber - 1);
PrecessionalElements p = c.Get(GetPrecessionalElements);
double years = c.Get(YearsSince2000);
// Initial coodinates for J2000 epoch
CrdsEquatorial eq0 = new CrdsEquatorial(star.Equatorial0);
// Take into account effect of proper motion:
// now coordinates are for the mean equinox of J2000.0,
// but for epoch of the target date
eq0.Alpha += star.PmAlpha * years / 3600.0;
eq0.Delta += star.PmDelta * years / 3600.0;
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, p);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, c.NutationElements, c.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, c.AberrationElements, c.Epsilon);
// Apparent coordinates of the star
eq += eq1 + eq2;
return(eq);
}
/// <summary>
/// Gets equatorial coordinates of comet tail end
/// </summary>
private CrdsEquatorial TailEquatorial(SkyContext ctx, Comet c)
{
var rBody = ctx.Get(RectangularH, c);
var rSun = ctx.Get(SunRectangular);
// distance from Sun
double r = Math.Sqrt(rBody.X * rBody.X + rBody.Y * rBody.Y + rBody.Z * rBody.Z);
double k = (r + ctx.Get(Appearance, c).Tail) / r;
double x = rSun.X + k * rBody.X;
double y = rSun.Y + k * rBody.Y;
double z = rSun.Z + k * rBody.Z;
// distance from Earth of tail end
double Delta = Math.Sqrt(x * x + y * y + z * z);
double alpha = Angle.ToDegrees(Math.Atan2(y, x));
double delta = Angle.ToDegrees(Math.Asin(z / Delta));
// geocentric equatoral for J2000.0
var eq0 = new CrdsEquatorial(alpha, delta);
// Precessinal elements to convert between epochs
var pe = ctx.Get(GetPrecessionalElements);
// Equatorial coordinates for the mean equinox and epoch of the target date
// No nutation an aberration corrections here, because we do not need high precision
return(Precession.GetEquatorialCoordinates(eq0, pe));
}
/// <summary>
/// Calculates equatorial geocentric coordinates of Pluto for current epoch
/// </summary>
private CrdsEquatorial Pluto_Equatorial0(SkyContext c)
{
PrecessionalElements pe = Precession.ElementsFK5(Date.EPOCH_J2000, c.JulianDay);
CrdsEquatorial eq2000 = c.Get(Pluto_EclipticalJ2000).ToEquatorial(epsilonJ2000);
return(Precession.GetEquatorialCoordinates(eq2000, pe));
}
public override void Calculate(SkyContext context)
{
// precessional elements
var p = Precession.ElementsFK5(Date.EPOCH_J2000, context.JulianDay);
foreach (var ds in DeepSkies)
{
ds.Equatorial = context.Get(Equatorial, ds);
ds.Horizontal = context.Get(Horizontal, ds);
if (ds.Outline != null)
{
foreach (var op in ds.Outline)
{
CrdsEquatorial eq0 = new CrdsEquatorial(op.Equatorial0);
// Equatorial coordinates for the mean equinox and epoch of the target date
var eq = Precession.GetEquatorialCoordinates(eq0, p);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, context.NutationElements, context.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, context.AberrationElements, context.Epsilon);
// Apparent coordinates of the object
eq += eq1 + eq2;
// Apparent horizontal coordinates
op.Horizontal = eq.ToHorizontal(context.GeoLocation, context.SiderealTime);
}
}
}
}
public void GetEquatorialCoordinates()
{
// Equatorial coordinates of Theta Persei
CrdsEquatorial eq0 = new CrdsEquatorial(new HMS(2, 44, 11.986), new DMS(49, 13, 42.48));
// proper motion of Theta Persei, units per year
CrdsEquatorial pm = new CrdsEquatorial(new HMS(0, 0, 0.03425), -new DMS(0, 0, 0.0895));
// target date (2018 November 13.19)
double jd = Date.JulianDay(new Date(2028, 11, 13.19));
Assert.AreEqual(2462088.69, jd);
// years since initial epoch
double years = (jd - Date.EPOCH_J2000) / 365.25;
// Take into account effect of proper motion:
// now coordinates are for the mean equinox of J2000.0,
// but for epoch of the target date
eq0.Alpha += pm.Alpha * years;
eq0.Delta += pm.Delta * years;
// precessional elements
var p = Precession.ElementsFK5(Date.EPOCH_J2000, jd);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, p);
// Check final results
Assert.AreEqual(new HMS(2, 46, 11.331), new HMS(eq.Alpha));
Assert.AreEqual(new DMS(49, 20, 54.54), new DMS(eq.Delta));
}
/// <summary>
/// Converts coordinates of telescope from epoch used by hardware to current epoch (used in sky map)
/// </summary>
/// <returns>Equatorial coordinates in current epoch</returns>
private CrdsEquatorial ConvertCoordinatesFromTelescopeEpoch()
{
double jd = new Date(DateTime.UtcNow).ToJulianEphemerisDay();
CrdsEquatorial eq = new CrdsEquatorial(telescope.RightAscension * 15, telescope.Declination);
switch (telescope.EquatorialSystem)
{
default:
case EquatorialCoordinateType.equOther:
case EquatorialCoordinateType.equTopocentric:
break;
case EquatorialCoordinateType.equB1950:
eq = Precession.GetEquatorialCoordinates(eq, Precession.ElementsFK5(Date.EPOCH_B1950, jd));
break;
case EquatorialCoordinateType.equJ2000:
eq = Precession.GetEquatorialCoordinates(eq, Precession.ElementsFK5(Date.EPOCH_J2000, jd));
break;
case EquatorialCoordinateType.equJ2050:
eq = Precession.GetEquatorialCoordinates(eq, Precession.ElementsFK5(Date.EPOCH_J2050, jd));
break;
}
return(eq);
}
/// <summary>
/// Converts coordinates in current epoch to an epoch used by telescope hardware.
/// </summary>
/// <param name="eq">Equatorial coordinates in current epoch (used by sky map)</param>
/// <returns>Coordinates in epoch used by telescope hardware</returns>
private CrdsEquatorial ConvertCoordinatesToTelescopeEpoch(CrdsEquatorial eq)
{
CrdsEquatorial eqT = new CrdsEquatorial(eq);
double jd0 = new Date(DateTime.UtcNow).ToJulianEphemerisDay();
switch (telescope.EquatorialSystem)
{
default:
case EquatorialCoordinateType.equOther:
case EquatorialCoordinateType.equTopocentric:
break;
case EquatorialCoordinateType.equB1950:
eqT = Precession.GetEquatorialCoordinates(eq, Precession.ElementsFK5(jd0, Date.EPOCH_B1950));
break;
case EquatorialCoordinateType.equJ2000:
eqT = Precession.GetEquatorialCoordinates(eq, Precession.ElementsFK5(jd0, Date.EPOCH_J2000));
break;
case EquatorialCoordinateType.equJ2050:
eqT = Precession.GetEquatorialCoordinates(eq, Precession.ElementsFK5(jd0, Date.EPOCH_J2050));
break;
}
return(eqT);
}
public override void Initialize()
{
// Ecliptic
LineEcliptic.FromHorizontal = (h, ctx) =>
{
var eq = h.ToEquatorial(ctx.GeoLocation, ctx.SiderealTime);
var ec = eq.ToEcliptical(ctx.Epsilon);
return(new GridPoint(ec.Lambda, ec.Beta));
};
LineEcliptic.ToHorizontal = (c, ctx) =>
{
var ec = new CrdsEcliptical(c.Longitude, c.Latitude);
var eq = ec.ToEquatorial(ctx.Epsilon);
return(eq.ToHorizontal(ctx.GeoLocation, ctx.SiderealTime));
};
// Galactic equator
LineGalactic.FromHorizontal = (h, ctx) =>
{
var eq = h.ToEquatorial(ctx.GeoLocation, ctx.SiderealTime);
var eq1950 = Precession.GetEquatorialCoordinates(eq, peTo1950);
var gal = eq1950.ToGalactical();
return(new GridPoint(gal.l, gal.b));
};
LineGalactic.ToHorizontal = (c, ctx) =>
{
var gal = new CrdsGalactical(c.Longitude, c.Latitude);
var eq1950 = gal.ToEquatorial();
var eq = Precession.GetEquatorialCoordinates(eq1950, peFrom1950);
return(eq.ToHorizontal(ctx.GeoLocation, ctx.SiderealTime));
};
// Meridian line
LineMeridian.FromHorizontal = (h, ctx) => new GridPoint(0, h.Azimuth - 180);
LineMeridian.ToHorizontal = (c, context) => new CrdsHorizontal(0, c.Longitude - 180);
// Horizontal grid
GridHorizontal.FromHorizontal = (h, ctx) => new GridPoint(h.Azimuth, h.Altitude);
GridHorizontal.ToHorizontal = (c, context) => new CrdsHorizontal(c.Longitude, c.Latitude);
// Equatorial grid
GridEquatorial.FromHorizontal = (h, ctx) =>
{
var eq = h.ToEquatorial(ctx.GeoLocation, ctx.SiderealTime);
return(new GridPoint(eq.Alpha, eq.Delta));
};
GridEquatorial.ToHorizontal = (c, ctx) =>
{
var eq = new CrdsEquatorial(c.Longitude, c.Latitude);
return(eq.ToHorizontal(ctx.GeoLocation, ctx.SiderealTime));
};
}
public override void Render(IMapContext map)
{
Graphics g = map.Graphics;
bool isGround = settings.Get <bool>("Ground");
bool isLabels = settings.Get <bool>("StarsLabels");
Brush brushNames = new SolidBrush(map.GetColor("ColorStarsLabels"));
if (map.MagLimit > 8 && settings.Get <bool>("Stars") && settings.Get <bool>("Tycho2"))
{
Brush brushStar = GetColor(map);
PrecessionalElements pe = Precession.ElementsFK5(map.JulianDay, Date.EPOCH_J2000);
var eq0 = map.Center.ToEquatorial(map.GeoLocation, map.SiderealTime);
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, pe);
SkyContext context = new SkyContext(map.JulianDay, map.GeoLocation);
tycho2.LockedStar = map.LockedObject as Tycho2Star;
tycho2.SelectedStar = map.SelectedObject as Tycho2Star;
var stars = tycho2.GetStars(context, eq, map.ViewAngle, m => MagFilter(map, m));
foreach (var star in stars)
{
if (!isGround || star.Horizontal.Altitude > 0)
{
PointF p = map.Project(star.Horizontal);
if (!map.IsOutOfScreen(p))
{
float size = map.GetPointSize(star.Magnitude);
if (map.Schema == ColorSchema.White)
{
g.FillEllipse(Brushes.White, p.X - size / 2 - 1, p.Y - size / 2 - 1, size + 2, size + 2);
}
g.FillEllipse(brushStar, p.X - size / 2, p.Y - size / 2, size, size);
if (isLabels && map.ViewAngle < 1 && size > 3)
{
map.DrawObjectCaption(fontNames, brushNames, star.ToString(), p, size);
}
map.AddDrawnObject(star);
}
}
}
}
}
public void FindConstellation()
{
// precessional elements for converting from J1950 to B1875 epoch
var p = Precession.ElementsFK5(Date.EPOCH_J1950, Date.EPOCH_B1875);
foreach (var test in testData)
{
// Equatorial coordinates for B1875 epoch
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(new CrdsEquatorial(test.RA, test.Dec), p);
// Constellation name
string con = Constellations.FindConstellation(eq);
// Check result
Assert.AreEqual(test.ConstName, con);
}
}
/// <summary>
/// Gets equatorial coordinates of deep sky object for current epoch
/// </summary>
private CrdsEquatorial Equatorial(SkyContext c, DeepSky ds)
{
PrecessionalElements p = c.Get(GetPrecessionalElements);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(ds.Equatorial0, p);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, c.NutationElements, c.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, c.AberrationElements, c.Epsilon);
// Apparent coordinates of the object
eq += eq1 + eq2;
return(eq);
}
private CrdsEquatorial StarEquatorial(SkyContext c, ConjunctedStar star)
{
PrecessionalElements p = c.Get(PrecessionalElements);
// Number of years, with fractions, since J2000 epoch
double years = (c.JulianDay - Date.EPOCH_J2000) / 365.25;
// Initial coodinates for J2000 epoch
CrdsEquatorial eq0 = new CrdsEquatorial(star.Equatorial0);
// Take into account effect of proper motion:
// now coordinates are for the mean equinox of J2000.0,
// but for epoch of the target date
eq0.Alpha += star.PmAlpha * years / 3600.0;
eq0.Delta += star.PmDelta * years / 3600.0;
// Equatorial coordinates for the mean equinox and epoch of the target date
// without aberration and nutation corrections
return(Precession.GetEquatorialCoordinates(eq0, p));
}
/// <summary>
/// Gets equatorial geocentrical coordinates for current epoch
/// </summary>
protected CrdsEquatorial EquatorialG(SkyContext c, T body)
{
// Precessinal elements to convert between epochs
var pe = c.Get(GetPrecessionalElements);
// Equatorial geocentrical coordinates for J2000 epoch
var eq0 = c.Get(EquatorialJ2000, body);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, pe);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, c.NutationElements, c.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, c.AberrationElements, c.Epsilon);
// Apparent coordinates of the object
eq += eq1 + eq2;
return(eq);
}
/// <summary>
/// Gets equatorial coordinates of a star for current epoch
/// </summary>
public CrdsEquatorial Equatorial(SkyContext c, Nova n)
{
PrecessionalElements p = c.Get(GetPrecessionalElements);
double years = c.Get(YearsSince2000);
// Initial coodinates for J2000 epoch
CrdsEquatorial eq0 = new CrdsEquatorial(n.Equatorial0);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, p);
// Nutation effect
var eq1 = Nutation.NutationEffect(eq, c.NutationElements, c.Epsilon);
// Aberration effect
var eq2 = Aberration.AberrationEffect(eq, c.AberrationElements, c.Epsilon);
// Apparent coordinates of the star
eq += eq1 + eq2;
return(eq);
}
/// <summary>
/// Gets equatorial coordinates of a star for current epoch
/// </summary>
private CrdsEquatorial Equatorial(SkyContext context, Tycho2Star star)
{
PrecessionalElements p = context.Get(PrecessionalElements);
double years = context.Get(YearsSince2000);
// Take into account effect of proper motion:
// now coordinates are for the mean equinox of J2000.0,
// but for epoch of the target date
var eq0 = star.Equatorial0 + new CrdsEquatorial(star.PmRA * years / 3600000, star.PmDec * years / 3600000);
// Equatorial coordinates for the mean equinox and epoch of the target date
CrdsEquatorial eq = Precession.GetEquatorialCoordinates(eq0, p);
// Nutation effect
var eqN = Nutation.NutationEffect(eq, context.NutationElements, context.Epsilon);
// Aberration effect
var eqA = Aberration.AberrationEffect(eq, context.AberrationElements, context.Epsilon);
// Apparent coordinates of the star
eq += eqN + eqA;
return(eq);
}