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	final double[][] computedJacobian2 = LLHCoordinatesSystem.ELLIPSODETIC.jacobianToCartesian(point);		final double[][] computedJacobian2 = LLHCoordinatesSystem.ELLIPSODETIC.jacobianToCartesian(point);
			</syntaxhighlight>

			The enumeration LLHCoordinatesSystem.ELLIPSODETIC allows the computation of the time derivatives of the LLH coordinates of a point. There are two algorithms implemented:
			* Analytical calculation for OneAxisEllipsoid
			* Finite-difference numerical calculation for all other types of ellipsoid, such as ThreeAxisEllipsoid

			The selection between the analytical and numerical method is automatic and the only function to call is the following:
			<syntaxhighlight lang="java">
			double[] LLHCoordinatesSystem.ELLIPSODETIC.computeLLHRates(final BodyShape bodyShape, final PVCoordinates pv, final Frame frame,
			final AbsoluteDate date)
			</syntaxhighlight>

			The longitude, latitude, and height rates are returned and expressed in rad/s, rad/s, et m/s respectively.

			Here is a full example of how to use this functionality:

			<syntaxhighlight lang="java">
			// Create Earth OneAxisEllipsoid
			final double ae = 6378137.0;// GRS80 constant
			final double flattening = 1.0 / 298.257222101;// GRS80 constant
			final CelestialBodyFrame itrf = FramesFactory.getITRF();
			final CelestialBodyFrame gcrf = FramesFactory.getGCRF();
			final OneAxisEllipsoid earth = new OneAxisEllipsoid(ae, flattening, itrf);
			final AbsoluteDate date = new AbsoluteDate(2010, 7, 9, 20, 30, 0);

			// Create orbit around the Earth in GCRF
			final double mu = 3.986005e14;// GRS80 constant
			final KeplerianOrbit orbit = KeplerianOrbit(ae + 700e3, 0.0, 0.5, 1.2, 1.1, 2.3, PositionAngle.TRUE, gcrf, date, mu);

			// Compute the rates using the analytical implementation
			final double[] rates = LLHCoordinatesSystem.ELLIPSODETIC
			.computeLLHRates(earth, orbit.getPVCoordinates(), gcrf, date);
	</syntaxhighlight>		</syntaxhighlight>

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User Manual 4.15 Celestial bodies - Historique des versions

Admin tsn le 28 novembre 2024 à 10:06

Admin tsn : Page créée avec « __NOTOC__ == Introduction == === Scope === The celestial bodies are described by their main features : position and geometry. The positions are ephemeris that must be loa... »

Admin tsn : Page créée avec « NOTOC == Introduction == === Scope === The celestial bodies are described by their main features : position and geometry. The positions are ephemeris that must be loa... »