public void TransitAndHourAngle()
{
// values from Astronomical Algorithms page 103
double longitude = -71.0833;
double Θ = 177.74208;
double α1 = 40.68021;
double α2 = 41.73129;
double α3 = 42.78204;
double m0 = Astronomical.ApproximateTransit(longitude,
/* siderealTime */ Θ, /* rightAscension */ α2);
Assert.IsTrue(m0.IsWithin(0.00001, 0.81965));
double transit = Astronomical.CorrectedTransit(
/* approximateTransit */ m0, longitude, /* siderealTime */ Θ,
/* rightAscension */ α2, /* previousRightAscension */ α1,
/* nextRightAscension */ α3) / 24;
Assert.IsTrue(transit.IsWithin(0.00001, 0.81980));
double δ1 = 18.04761;
double δ2 = 18.44092;
double δ3 = 18.82742;
double rise = Astronomical.CorrectedHourAngle(/* approximateTransit */ m0,
/* angle */ -0.5667, new Coordinates(/* latitude */ 42.3333, longitude),
/* afterTransit */ false, /* siderealTime */ Θ,
/* rightAscension */ α2, /* previousRightAscension */ α1,
/* nextRightAscension */ α3, /* declination */ δ2,
/* previousDeclination */ δ1, /* nextDeclination */ δ3) / 24;
Assert.IsTrue(rise.IsWithin(0.00001, 0.51766));
}
public void AltitudeOfCelestialBody()
{
double φ = 38 + (55 / 60.0) + (17.0 / 3600);
double δ = -6 - (43 / 60.0) - (11.61 / 3600);
double H = 64.352133;
double h = Astronomical.AltitudeOfCelestialBody(
/* observerLatitude */ φ, /* declination */ δ, /* localHourAngle */ H);
Assert.IsTrue(h.IsWithin(0.0001, 15.1249));
}
public void AngleInterpolation()
{
double i1 = Astronomical.InterpolateAngles(/* value */ 1, /* previousValue */ -1,
/* nextValue */ 3, /* factor */ 0.6);
Assert.IsTrue(i1.IsWithin(0.000001, 2.2));
double i2 = Astronomical.InterpolateAngles(/* value */ 1, /* previousValue */ 359,
/* nextValue */ 3, /* factor */ 0.6);
Assert.IsTrue(i2.IsWithin(0.000001, 2.2));
}
public void Interpolation()
{
// values from Astronomical Algorithms page 25
double interpolatedValue = Astronomical.Interpolate(/* value */ 0.877366,
/* previousValue */ 0.884226, /* nextValue */ 0.870531, /* factor */ 4.35 / 24);
Assert.IsTrue(interpolatedValue.IsWithin(0.000001, 0.876125));
double i1 = Astronomical.Interpolate(
/* value */ 1, /* previousValue */ -1, /* nextValue */ 3, /* factor */ 0.6);
Assert.IsTrue(i1.IsWithin(0.000001, 2.2));
}
public void SolarCoordinates()
{
// values from Astronomical Algorithms page 165
double jd = CalendricalHelper.JulianDay(/* year */ 1992, /* month */ 10, /* day */ 13);
SolarCoordinates solar = new SolarCoordinates(/* JulianDay */ jd);
double T = CalendricalHelper.JulianCentury(/* JulianDay */ jd);
double L0 = Astronomical.MeanSolarLongitude(/* julianCentury */ T);
double ε0 = Astronomical.MeanObliquityOfTheEcliptic(/* julianCentury */ T);
double εapp = Astronomical.ApparentObliquityOfTheEcliptic(
/* julianCentury */ T, /* meanObliquityOfTheEcliptic */ ε0);
double M = Astronomical.MeanSolarAnomaly(/* julianCentury */ T);
double C = Astronomical.SolarEquationOfTheCenter(
/* julianCentury */ T, /* meanAnomaly */ M);
double λ = Astronomical.ApparentSolarLongitude(
/* julianCentury */ T, /* meanLongitude */ L0);
double δ = solar.Declination;
double α = DoubleUtil.UnwindAngle(solar.RightAscension);
Assert.IsTrue(T.IsWithin(0.00000000001, (-0.072183436)));
Assert.IsTrue(L0.IsWithin(0.00001, (201.80720)));
Assert.IsTrue(ε0.IsWithin(0.00001, (23.44023)));
Assert.IsTrue(εapp.IsWithin(0.00001, (23.43999)));
Assert.IsTrue(M.IsWithin(0.00001, (278.99397)));
Assert.IsTrue(C.IsWithin(0.00001, (-1.89732)));
// lower accuracy than desired
Assert.IsTrue(λ.IsWithin(0.00002, (199.90895)));
Assert.IsTrue(δ.IsWithin(0.00001, (-7.78507)));
Assert.IsTrue(α.IsWithin(0.00001, (198.38083)));
// values from Astronomical Algorithms page 88
jd = CalendricalHelper.JulianDay(/* year */ 1987, /* month */ 4, /* day */ 10);
solar = new SolarCoordinates(/* JulianDay */ jd);
T = CalendricalHelper.JulianCentury(/* JulianDay */ jd);
double θ0 = Astronomical.MeanSiderealTime(/* julianCentury */ T);
double θapp = solar.ApparentSiderealTime;
double Ω = Astronomical.AscendingLunarNodeLongitude(/* julianCentury */ T);
ε0 = Astronomical.MeanObliquityOfTheEcliptic(/* julianCentury */ T);
L0 = Astronomical.MeanSolarLongitude(/* julianCentury */ T);
double Lp = Astronomical.MeanLunarLongitude(/* julianCentury */ T);
double ΔΨ = Astronomical.NutationInLongitude(/* julianCentury */ T,
/* solarLongitude */ L0, /* lunarLongitude */ Lp, /* ascendingNode */ Ω);
double Δε = Astronomical.NutationInObliquity(/* julianCentury */ T,
/* solarLongitude */ L0, /* lunarLongitude */ Lp, /* ascendingNode */ Ω);
double ε = ε0 + Δε;
Assert.IsTrue(θ0.IsWithin(0.000001, (197.693195)));
Assert.IsTrue(θapp.IsWithin(0.0001, (197.6922295833)));
// values from Astronomical Algorithms page 148
Assert.IsTrue(Ω.IsWithin(0.0001, (11.2531)));
Assert.IsTrue(ΔΨ.IsWithin(0.0001, (-0.0010522)));
Assert.IsTrue(Δε.IsWithin(0.00001, (0.0026230556)));
Assert.IsTrue(ε0.IsWithin(0.000001, (23.4409463889)));
Assert.IsTrue(ε.IsWithin(0.00001, (23.4435694444)));
}
