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import defined from "./defined.js";
import DeveloperError from "./DeveloperError.js";
import JulianDate from "./JulianDate.js";
import CesiumMath from "./Math.js";
import Matrix3 from "./Matrix3.js";
import TimeConstants from "./TimeConstants.js";
import TimeStandard from "./TimeStandard.js";
/**
* Contains functions for finding the Cartesian coordinates of the sun and the moon in the
* Earth-centered inertial frame.
*
* @namespace Simon1994PlanetaryPositions
*/
const Simon1994PlanetaryPositions = {};
function computeTdbMinusTtSpice(daysSinceJ2000InTerrestrialTime) {
/* STK Comments ------------------------------------------------------
* This function uses constants designed to be consistent with
* the SPICE Toolkit from JPL version N0051 (unitim.c)
* M0 = 6.239996
* M0Dot = 1.99096871e-7 rad/s = 0.01720197 rad/d
* EARTH_ECC = 1.671e-2
* TDB_AMPL = 1.657e-3 secs
*--------------------------------------------------------------------*/
//* Values taken as specified in STK Comments except: 0.01720197 rad/day = 1.99096871e-7 rad/sec
//* Here we use the more precise value taken from the SPICE value 1.99096871e-7 rad/sec converted to rad/day
//* All other constants are consistent with the SPICE implementation of the TDB conversion
//* except where we treat the independent time parameter to be in TT instead of TDB.
//* This is an approximation made to facilitate performance due to the higher prevalance of
//* the TT2TDB conversion over TDB2TT in order to avoid having to iterate when converting to TDB for the JPL ephemeris.
//* Days are used instead of seconds to provide a slight improvement in numerical precision.
//* For more information see:
//* http://www.cv.nrao.edu/~rfisher/Ephemerides/times.html#TDB
//* ftp://ssd.jpl.nasa.gov/pub/eph/planets/ioms/ExplSupplChap8.pdf
const g = 6.239996 + 0.0172019696544 * daysSinceJ2000InTerrestrialTime;
return 1.657e-3 * Math.sin(g + 1.671e-2 * Math.sin(g));
}
const TdtMinusTai = 32.184;
const J2000d = 2451545;
function taiToTdb(date, result) {
//Converts TAI to TT
result = JulianDate.addSeconds(date, TdtMinusTai, result);
//Converts TT to TDB
const days = JulianDate.totalDays(result) - J2000d;
result = JulianDate.addSeconds(result, computeTdbMinusTtSpice(days), result);
return result;
}
const epoch = new JulianDate(2451545, 0, TimeStandard.TAI); //Actually TDB (not TAI)
const MetersPerKilometer = 1000.0;
const RadiansPerDegree = CesiumMath.RADIANS_PER_DEGREE;
const RadiansPerArcSecond = CesiumMath.RADIANS_PER_ARCSECOND;
const MetersPerAstronomicalUnit = 1.4959787e11; // IAU 1976 value
const perifocalToEquatorial = new Matrix3();
function elementsToCartesian(
semimajorAxis,
eccentricity,
inclination,
longitudeOfPerigee,
longitudeOfNode,
meanLongitude,
result,
) {
if (inclination < 0.0) {
inclination = -inclination;
longitudeOfNode += CesiumMath.PI;
}
//>>includeStart('debug', pragmas.debug);
Iif (inclination < 0 || inclination > CesiumMath.PI) {
throw new DeveloperError(
"The inclination is out of range. Inclination must be greater than or equal to zero and less than or equal to Pi radians.",
);
}
//>>includeEnd('debug');
const radiusOfPeriapsis = semimajorAxis * (1.0 - eccentricity);
const argumentOfPeriapsis = longitudeOfPerigee - longitudeOfNode;
const rightAscensionOfAscendingNode = longitudeOfNode;
const trueAnomaly = meanAnomalyToTrueAnomaly(
meanLongitude - longitudeOfPerigee,
eccentricity,
);
const type = chooseOrbit(eccentricity, 0.0);
//>>includeStart('debug', pragmas.debug);
Iif (
type === "Hyperbolic" &&
Math.abs(CesiumMath.negativePiToPi(trueAnomaly)) >=
Math.acos(-1.0 / eccentricity)
) {
throw new DeveloperError(
"The true anomaly of the hyperbolic orbit lies outside of the bounds of the hyperbola.",
);
}
//>>includeEnd('debug');
perifocalToCartesianMatrix(
argumentOfPeriapsis,
inclination,
rightAscensionOfAscendingNode,
perifocalToEquatorial,
);
const semilatus = radiusOfPeriapsis * (1.0 + eccentricity);
const costheta = Math.cos(trueAnomaly);
const sintheta = Math.sin(trueAnomaly);
const denom = 1.0 + eccentricity * costheta;
//>>includeStart('debug', pragmas.debug);
Iif (denom <= CesiumMath.Epsilon10) {
throw new DeveloperError("elements cannot be converted to cartesian");
}
//>>includeEnd('debug');
const radius = semilatus / denom;
if (!defined(result)) {
result = new Cartesian3(radius * costheta, radius * sintheta, 0.0);
} else {
result.x = radius * costheta;
result.y = radius * sintheta;
result.z = 0.0;
}
return Matrix3.multiplyByVector(perifocalToEquatorial, result, result);
}
function chooseOrbit(eccentricity, tolerance) {
//>>includeStart('debug', pragmas.debug);
Iif (eccentricity < 0) {
throw new DeveloperError("eccentricity cannot be negative.");
}
//>>includeEnd('debug');
Iif (eccentricity <= tolerance) {
return "Circular";
} else if (eccentricity < 1.0 - tolerance) {
return "Elliptical";
} else Eif (eccentricity <= 1.0 + tolerance) {
return "Parabolic";
}
return "Hyperbolic";
}
// Calculates the true anomaly given the mean anomaly and the eccentricity.
function meanAnomalyToTrueAnomaly(meanAnomaly, eccentricity) {
//>>includeStart('debug', pragmas.debug);
Iif (eccentricity < 0.0 || eccentricity >= 1.0) {
throw new DeveloperError("eccentricity out of range.");
}
//>>includeEnd('debug');
const eccentricAnomaly = meanAnomalyToEccentricAnomaly(
meanAnomaly,
eccentricity,
);
return eccentricAnomalyToTrueAnomaly(eccentricAnomaly, eccentricity);
}
const maxIterationCount = 50;
const keplerEqConvergence = CesiumMath.EPSILON8;
// Calculates the eccentric anomaly given the mean anomaly and the eccentricity.
function meanAnomalyToEccentricAnomaly(meanAnomaly, eccentricity) {
//>>includeStart('debug', pragmas.debug);
Iif (eccentricity < 0.0 || eccentricity >= 1.0) {
throw new DeveloperError("eccentricity out of range.");
}
//>>includeEnd('debug');
const revs = Math.floor(meanAnomaly / CesiumMath.TWO_PI);
// Find angle in current revolution
meanAnomaly -= revs * CesiumMath.TWO_PI;
// calculate starting value for iteration sequence
let iterationValue =
meanAnomaly +
(eccentricity * Math.sin(meanAnomaly)) /
(1.0 - Math.sin(meanAnomaly + eccentricity) + Math.sin(meanAnomaly));
// Perform Newton-Raphson iteration on Kepler's equation
let eccentricAnomaly = Number.MAX_VALUE;
let count;
for (
count = 0;
count < maxIterationCount &&
Math.abs(eccentricAnomaly - iterationValue) > keplerEqConvergence;
++count
) {
eccentricAnomaly = iterationValue;
const NRfunction =
eccentricAnomaly -
eccentricity * Math.sin(eccentricAnomaly) -
meanAnomaly;
const dNRfunction = 1 - eccentricity * Math.cos(eccentricAnomaly);
iterationValue = eccentricAnomaly - NRfunction / dNRfunction;
}
//>>includeStart('debug', pragmas.debug);
Iif (count >= maxIterationCount) {
throw new DeveloperError("Kepler equation did not converge");
// STK Components uses a numerical method to find the eccentric anomaly in the case that Kepler's
// equation does not converge. We don't expect that to ever be necessary for the reasonable orbits used here.
}
//>>includeEnd('debug');
eccentricAnomaly = iterationValue + revs * CesiumMath.TWO_PI;
return eccentricAnomaly;
}
// Calculates the true anomaly given the eccentric anomaly and the eccentricity.
function eccentricAnomalyToTrueAnomaly(eccentricAnomaly, eccentricity) {
//>>includeStart('debug', pragmas.debug);
Iif (eccentricity < 0.0 || eccentricity >= 1.0) {
throw new DeveloperError("eccentricity out of range.");
}
//>>includeEnd('debug');
// Calculate the number of previous revolutions
const revs = Math.floor(eccentricAnomaly / CesiumMath.TWO_PI);
// Find angle in current revolution
eccentricAnomaly -= revs * CesiumMath.TWO_PI;
// Calculate true anomaly from eccentric anomaly
const trueAnomalyX = Math.cos(eccentricAnomaly) - eccentricity;
const trueAnomalyY =
Math.sin(eccentricAnomaly) * Math.sqrt(1 - eccentricity * eccentricity);
let trueAnomaly = Math.atan2(trueAnomalyY, trueAnomalyX);
// Ensure the correct quadrant
trueAnomaly = CesiumMath.zeroToTwoPi(trueAnomaly);
Iif (eccentricAnomaly < 0) {
trueAnomaly -= CesiumMath.TWO_PI;
}
// Add on previous revolutions
trueAnomaly += revs * CesiumMath.TWO_PI;
return trueAnomaly;
}
// Calculates the transformation matrix to convert from the perifocal (PQW) coordinate
// system to inertial cartesian coordinates.
function perifocalToCartesianMatrix(
argumentOfPeriapsis,
inclination,
rightAscension,
result,
) {
//>>includeStart('debug', pragmas.debug);
Iif (inclination < 0 || inclination > CesiumMath.PI) {
throw new DeveloperError("inclination out of range");
}
//>>includeEnd('debug');
const cosap = Math.cos(argumentOfPeriapsis);
const sinap = Math.sin(argumentOfPeriapsis);
const cosi = Math.cos(inclination);
const sini = Math.sin(inclination);
const cosraan = Math.cos(rightAscension);
const sinraan = Math.sin(rightAscension);
Iif (!defined(result)) {
result = new Matrix3(
cosraan * cosap - sinraan * sinap * cosi,
-cosraan * sinap - sinraan * cosap * cosi,
sinraan * sini,
sinraan * cosap + cosraan * sinap * cosi,
-sinraan * sinap + cosraan * cosap * cosi,
-cosraan * sini,
sinap * sini,
cosap * sini,
cosi,
);
} else {
result[0] = cosraan * cosap - sinraan * sinap * cosi;
result[1] = sinraan * cosap + cosraan * sinap * cosi;
result[2] = sinap * sini;
result[3] = -cosraan * sinap - sinraan * cosap * cosi;
result[4] = -sinraan * sinap + cosraan * cosap * cosi;
result[5] = cosap * sini;
result[6] = sinraan * sini;
result[7] = -cosraan * sini;
result[8] = cosi;
}
return result;
}
// From section 5.8
const semiMajorAxis0 = 1.0000010178 * MetersPerAstronomicalUnit;
const meanLongitude0 = 100.46645683 * RadiansPerDegree;
const meanLongitude1 = 1295977422.83429 * RadiansPerArcSecond;
// From table 6
const p1u = 16002;
const p2u = 21863;
const p3u = 32004;
const p4u = 10931;
const p5u = 14529;
const p6u = 16368;
const p7u = 15318;
const p8u = 32794;
const Ca1 = 64 * 1e-7 * MetersPerAstronomicalUnit;
const Ca2 = -152 * 1e-7 * MetersPerAstronomicalUnit;
const Ca3 = 62 * 1e-7 * MetersPerAstronomicalUnit;
const Ca4 = -8 * 1e-7 * MetersPerAstronomicalUnit;
const Ca5 = 32 * 1e-7 * MetersPerAstronomicalUnit;
const Ca6 = -41 * 1e-7 * MetersPerAstronomicalUnit;
const Ca7 = 19 * 1e-7 * MetersPerAstronomicalUnit;
const Ca8 = -11 * 1e-7 * MetersPerAstronomicalUnit;
const Sa1 = -150 * 1e-7 * MetersPerAstronomicalUnit;
const Sa2 = -46 * 1e-7 * MetersPerAstronomicalUnit;
const Sa3 = 68 * 1e-7 * MetersPerAstronomicalUnit;
const Sa4 = 54 * 1e-7 * MetersPerAstronomicalUnit;
const Sa5 = 14 * 1e-7 * MetersPerAstronomicalUnit;
const Sa6 = 24 * 1e-7 * MetersPerAstronomicalUnit;
const Sa7 = -28 * 1e-7 * MetersPerAstronomicalUnit;
const Sa8 = 22 * 1e-7 * MetersPerAstronomicalUnit;
const q1u = 10;
const q2u = 16002;
const q3u = 21863;
const q4u = 10931;
const q5u = 1473;
const q6u = 32004;
const q7u = 4387;
const q8u = 73;
const Cl1 = -325 * 1e-7;
const Cl2 = -322 * 1e-7;
const Cl3 = -79 * 1e-7;
const Cl4 = 232 * 1e-7;
const Cl5 = -52 * 1e-7;
const Cl6 = 97 * 1e-7;
const Cl7 = 55 * 1e-7;
const Cl8 = -41 * 1e-7;
const Sl1 = -105 * 1e-7;
const Sl2 = -137 * 1e-7;
const Sl3 = 258 * 1e-7;
const Sl4 = 35 * 1e-7;
const Sl5 = -116 * 1e-7;
const Sl6 = -88 * 1e-7;
const Sl7 = -112 * 1e-7;
const Sl8 = -80 * 1e-7;
const scratchDate = new JulianDate(0, 0.0, TimeStandard.TAI);
// Gets a point describing the motion of the Earth-Moon barycenter according to the equations described in section 6.
function computeSimonEarthMoonBarycenter(date, result) {
// t is thousands of years from J2000 TDB
taiToTdb(date, scratchDate);
const x =
scratchDate.dayNumber -
epoch.dayNumber +
(scratchDate.secondsOfDay - epoch.secondsOfDay) /
TimeConstants.SECONDS_PER_DAY;
const t = x / (TimeConstants.DAYS_PER_JULIAN_CENTURY * 10.0);
const u = 0.3595362 * t;
const semimajorAxis =
semiMajorAxis0 +
Ca1 * Math.cos(p1u * u) +
Sa1 * Math.sin(p1u * u) +
Ca2 * Math.cos(p2u * u) +
Sa2 * Math.sin(p2u * u) +
Ca3 * Math.cos(p3u * u) +
Sa3 * Math.sin(p3u * u) +
Ca4 * Math.cos(p4u * u) +
Sa4 * Math.sin(p4u * u) +
Ca5 * Math.cos(p5u * u) +
Sa5 * Math.sin(p5u * u) +
Ca6 * Math.cos(p6u * u) +
Sa6 * Math.sin(p6u * u) +
Ca7 * Math.cos(p7u * u) +
Sa7 * Math.sin(p7u * u) +
Ca8 * Math.cos(p8u * u) +
Sa8 * Math.sin(p8u * u);
const meanLongitude =
meanLongitude0 +
meanLongitude1 * t +
Cl1 * Math.cos(q1u * u) +
Sl1 * Math.sin(q1u * u) +
Cl2 * Math.cos(q2u * u) +
Sl2 * Math.sin(q2u * u) +
Cl3 * Math.cos(q3u * u) +
Sl3 * Math.sin(q3u * u) +
Cl4 * Math.cos(q4u * u) +
Sl4 * Math.sin(q4u * u) +
Cl5 * Math.cos(q5u * u) +
Sl5 * Math.sin(q5u * u) +
Cl6 * Math.cos(q6u * u) +
Sl6 * Math.sin(q6u * u) +
Cl7 * Math.cos(q7u * u) +
Sl7 * Math.sin(q7u * u) +
Cl8 * Math.cos(q8u * u) +
Sl8 * Math.sin(q8u * u);
// All constants in this part are from section 5.8
const eccentricity = 0.0167086342 - 0.0004203654 * t;
const longitudeOfPerigee =
102.93734808 * RadiansPerDegree + 11612.3529 * RadiansPerArcSecond * t;
const inclination = 469.97289 * RadiansPerArcSecond * t;
const longitudeOfNode =
174.87317577 * RadiansPerDegree - 8679.27034 * RadiansPerArcSecond * t;
return elementsToCartesian(
semimajorAxis,
eccentricity,
inclination,
longitudeOfPerigee,
longitudeOfNode,
meanLongitude,
result,
);
}
// Gets a point describing the position of the moon according to the equations described in section 4.
function computeSimonMoon(date, result) {
taiToTdb(date, scratchDate);
const x =
scratchDate.dayNumber -
epoch.dayNumber +
(scratchDate.secondsOfDay - epoch.secondsOfDay) /
TimeConstants.SECONDS_PER_DAY;
const t = x / TimeConstants.DAYS_PER_JULIAN_CENTURY;
const t2 = t * t;
const t3 = t2 * t;
const t4 = t3 * t;
// Terms from section 3.4 (b.1)
let semimajorAxis = 383397.7725 + 0.004 * t;
let eccentricity = 0.055545526 - 0.000000016 * t;
const inclinationConstant = 5.15668983 * RadiansPerDegree;
let inclinationSecPart =
-0.00008 * t + 0.02966 * t2 - 0.000042 * t3 - 0.00000013 * t4;
const longitudeOfPerigeeConstant = 83.35324312 * RadiansPerDegree;
let longitudeOfPerigeeSecPart =
14643420.2669 * t - 38.2702 * t2 - 0.045047 * t3 + 0.00021301 * t4;
const longitudeOfNodeConstant = 125.04455501 * RadiansPerDegree;
let longitudeOfNodeSecPart =
-6967919.3631 * t + 6.3602 * t2 + 0.007625 * t3 - 0.00003586 * t4;
const meanLongitudeConstant = 218.31664563 * RadiansPerDegree;
let meanLongitudeSecPart =
1732559343.4847 * t - 6.391 * t2 + 0.006588 * t3 - 0.00003169 * t4;
// Delaunay arguments from section 3.5 b
const D =
297.85019547 * RadiansPerDegree +
RadiansPerArcSecond *
(1602961601.209 * t - 6.3706 * t2 + 0.006593 * t3 - 0.00003169 * t4);
const F =
93.27209062 * RadiansPerDegree +
RadiansPerArcSecond *
(1739527262.8478 * t - 12.7512 * t2 - 0.001037 * t3 + 0.00000417 * t4);
const l =
134.96340251 * RadiansPerDegree +
RadiansPerArcSecond *
(1717915923.2178 * t + 31.8792 * t2 + 0.051635 * t3 - 0.0002447 * t4);
const lprime =
357.52910918 * RadiansPerDegree +
RadiansPerArcSecond *
(129596581.0481 * t - 0.5532 * t2 + 0.000136 * t3 - 0.00001149 * t4);
const psi =
310.17137918 * RadiansPerDegree -
RadiansPerArcSecond *
(6967051.436 * t + 6.2068 * t2 + 0.007618 * t3 - 0.00003219 * t4);
// Add terms from Table 4
const twoD = 2.0 * D;
const fourD = 4.0 * D;
const sixD = 6.0 * D;
const twol = 2.0 * l;
const threel = 3.0 * l;
const fourl = 4.0 * l;
const twoF = 2.0 * F;
semimajorAxis +=
3400.4 * Math.cos(twoD) -
635.6 * Math.cos(twoD - l) -
235.6 * Math.cos(l) +
218.1 * Math.cos(twoD - lprime) +
181.0 * Math.cos(twoD + l);
eccentricity +=
0.014216 * Math.cos(twoD - l) +
0.008551 * Math.cos(twoD - twol) -
0.001383 * Math.cos(l) +
0.001356 * Math.cos(twoD + l) -
0.001147 * Math.cos(fourD - threel) -
0.000914 * Math.cos(fourD - twol) +
0.000869 * Math.cos(twoD - lprime - l) -
0.000627 * Math.cos(twoD) -
0.000394 * Math.cos(fourD - fourl) +
0.000282 * Math.cos(twoD - lprime - twol) -
0.000279 * Math.cos(D - l) -
0.000236 * Math.cos(twol) +
0.000231 * Math.cos(fourD) +
0.000229 * Math.cos(sixD - fourl) -
0.000201 * Math.cos(twol - twoF);
inclinationSecPart +=
486.26 * Math.cos(twoD - twoF) -
40.13 * Math.cos(twoD) +
37.51 * Math.cos(twoF) +
25.73 * Math.cos(twol - twoF) +
19.97 * Math.cos(twoD - lprime - twoF);
longitudeOfPerigeeSecPart +=
-55609 * Math.sin(twoD - l) -
34711 * Math.sin(twoD - twol) -
9792 * Math.sin(l) +
9385 * Math.sin(fourD - threel) +
7505 * Math.sin(fourD - twol) +
5318 * Math.sin(twoD + l) +
3484 * Math.sin(fourD - fourl) -
3417 * Math.sin(twoD - lprime - l) -
2530 * Math.sin(sixD - fourl) -
2376 * Math.sin(twoD) -
2075 * Math.sin(twoD - threel) -
1883 * Math.sin(twol) -
1736 * Math.sin(sixD - 5.0 * l) +
1626 * Math.sin(lprime) -
1370 * Math.sin(sixD - threel);
longitudeOfNodeSecPart +=
-5392 * Math.sin(twoD - twoF) -
540 * Math.sin(lprime) -
441 * Math.sin(twoD) +
423 * Math.sin(twoF) -
288 * Math.sin(twol - twoF);
meanLongitudeSecPart +=
-3332.9 * Math.sin(twoD) +
1197.4 * Math.sin(twoD - l) -
662.5 * Math.sin(lprime) +
396.3 * Math.sin(l) -
218.0 * Math.sin(twoD - lprime);
// Add terms from Table 5
const twoPsi = 2.0 * psi;
const threePsi = 3.0 * psi;
inclinationSecPart +=
46.997 * Math.cos(psi) * t -
0.614 * Math.cos(twoD - twoF + psi) * t +
0.614 * Math.cos(twoD - twoF - psi) * t -
0.0297 * Math.cos(twoPsi) * t2 -
0.0335 * Math.cos(psi) * t2 +
0.0012 * Math.cos(twoD - twoF + twoPsi) * t2 -
0.00016 * Math.cos(psi) * t3 +
0.00004 * Math.cos(threePsi) * t3 +
0.00004 * Math.cos(twoPsi) * t3;
const perigeeAndMean =
2.116 * Math.sin(psi) * t -
0.111 * Math.sin(twoD - twoF - psi) * t -
0.0015 * Math.sin(psi) * t2;
longitudeOfPerigeeSecPart += perigeeAndMean;
meanLongitudeSecPart += perigeeAndMean;
longitudeOfNodeSecPart +=
-520.77 * Math.sin(psi) * t +
13.66 * Math.sin(twoD - twoF + psi) * t +
1.12 * Math.sin(twoD - psi) * t -
1.06 * Math.sin(twoF - psi) * t +
0.66 * Math.sin(twoPsi) * t2 +
0.371 * Math.sin(psi) * t2 -
0.035 * Math.sin(twoD - twoF + twoPsi) * t2 -
0.015 * Math.sin(twoD - twoF + psi) * t2 +
0.0014 * Math.sin(psi) * t3 -
0.0011 * Math.sin(threePsi) * t3 -
0.0009 * Math.sin(twoPsi) * t3;
// Add constants and convert units
semimajorAxis *= MetersPerKilometer;
const inclination =
inclinationConstant + inclinationSecPart * RadiansPerArcSecond;
const longitudeOfPerigee =
longitudeOfPerigeeConstant +
longitudeOfPerigeeSecPart * RadiansPerArcSecond;
const meanLongitude =
meanLongitudeConstant + meanLongitudeSecPart * RadiansPerArcSecond;
const longitudeOfNode =
longitudeOfNodeConstant + longitudeOfNodeSecPart * RadiansPerArcSecond;
return elementsToCartesian(
semimajorAxis,
eccentricity,
inclination,
longitudeOfPerigee,
longitudeOfNode,
meanLongitude,
result,
);
}
// Gets a point describing the motion of the Earth. This point uses the Moon point and
// the 1992 mu value (ratio between Moon and Earth masses) in Table 2 of the paper in order
// to determine the position of the Earth relative to the Earth-Moon barycenter.
const moonEarthMassRatio = 0.012300034; // From 1992 mu value in Table 2
const factor = (moonEarthMassRatio / (moonEarthMassRatio + 1.0)) * -1;
function computeSimonEarth(date, result) {
result = computeSimonMoon(date, result);
return Cartesian3.multiplyByScalar(result, factor, result);
}
// Values for the <code>axesTransformation</code> needed for the rotation were found using the STK Components
// GeographicTransformer on the position of the sun center of mass point and the earth J2000 frame.
const axesTransformation = new Matrix3(
1.0000000000000002,
5.619723173785822e-16,
4.690511510146299e-19,
-5.154129427414611e-16,
0.9174820620691819,
-0.39777715593191376,
-2.23970096136568e-16,
0.39777715593191376,
0.9174820620691819,
);
let translation = new Cartesian3();
/**
* Computes the position of the Sun in the Earth-centered inertial frame
*
* @param {JulianDate} [julianDate] The time at which to compute the Sun's position, if not provided the current system time is used.
* @param {Cartesian3} [result] The object onto which to store the result.
* @returns {Cartesian3} Calculated sun position
*/
Simon1994PlanetaryPositions.computeSunPositionInEarthInertialFrame = function (
julianDate,
result,
) {
if (!defined(julianDate)) {
julianDate = JulianDate.now();
}
if (!defined(result)) {
result = new Cartesian3();
}
//first forward transformation
translation = computeSimonEarthMoonBarycenter(julianDate, translation);
result = Cartesian3.negate(translation, result);
//second forward transformation
computeSimonEarth(julianDate, translation);
Cartesian3.subtract(result, translation, result);
Matrix3.multiplyByVector(axesTransformation, result, result);
return result;
};
/**
* Computes the position of the Moon in the Earth-centered inertial frame
*
* @param {JulianDate} [julianDate] The time at which to compute the Moon's position, if not provided the current system time is used.
* @param {Cartesian3} [result] The object onto which to store the result.
* @returns {Cartesian3} Calculated moon position
*/
Simon1994PlanetaryPositions.computeMoonPositionInEarthInertialFrame = function (
julianDate,
result,
) {
Iif (!defined(julianDate)) {
julianDate = JulianDate.now();
}
result = computeSimonMoon(julianDate, result);
Matrix3.multiplyByVector(axesTransformation, result, result);
return result;
};
export default Simon1994PlanetaryPositions;
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