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 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);
}
}
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>
/// 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));
}
/// <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 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);
}
}
public override void Render(IMapContext map)
{
peFrom1950 = Precession.ElementsFK5(Date.EPOCH_B1950, map.JulianDay);
peTo1950 = Precession.ElementsFK5(map.JulianDay, Date.EPOCH_B1950);
Color colorGridEquatorial = map.GetColor("ColorEquatorialGrid");
Color colorGridHorizontal = map.GetColor("ColorHorizontalGrid");
Color colorLineEcliptic = map.GetColor("ColorEcliptic");
Color colorLineGalactic = map.GetColor("ColorGalacticEquator");
Color colorLineMeridian = map.GetColor("ColorMeridian");
penGridEquatorial.Color = colorGridEquatorial;
penGridHorizontal.Color = colorGridHorizontal;
penLineEcliptic.Color = colorLineEcliptic;
penLineGalactic.Color = colorLineGalactic;
penLineMeridian.Color = colorLineMeridian;
if (settings.Get <bool>("GalacticEquator"))
{
DrawGrid(map, penLineGalactic, LineGalactic);
}
if (settings.Get <bool>("EquatorialGrid"))
{
DrawGrid(map, penGridEquatorial, GridEquatorial);
DrawEquatorialPoles(map);
}
if (settings.Get <bool>("HorizontalGrid"))
{
DrawGrid(map, penGridHorizontal, GridHorizontal);
DrawHorizontalPoles(map);
}
if (settings.Get <bool>("EclipticLine"))
{
DrawGrid(map, penLineEcliptic, LineEcliptic);
DrawEquinoxLabels(map);
DrawLunarNodes(map);
}
if (settings.Get <bool>("MeridianLine"))
{
DrawGrid(map, penLineMeridian, LineMeridian);
}
}
/// <summary>
/// Gets precessional elements to convert equatorial coordinates of stars to current epoch
/// </summary>
private PrecessionalElements PrecessionalElements(SkyContext context)
{
return(Precession.ElementsFK5(Date.EPOCH_J2000, context.JulianDay));
}
/// <summary>
/// Gets precessional elements to convert equatorial coordinates of minor body to current epoch
/// </summary>
protected PrecessionalElements GetPrecessionalElements(SkyContext c)
{
return(Precession.ElementsFK5(Date.EPOCH_J2000, c.JulianDay));
}