public class NumericalPropagationWithAttitude {
public static void main(String[] args) throws PatriusException {
// Patrius Dataset initialization (needed for example to get the UTC time)
PatriusDataset.addResourcesFromPatriusDataset() ;
// Recovery of the UTC time scale using a "factory" (not to duplicate such unique object)
final TimeScale TUC = TimeScalesFactory.getUTC();
// Date of the orbit given in UTC time scale)
final AbsoluteDate date = new AbsoluteDate("2010-01-01T12:00:00.000", TUC);
// Getting the frame with wich will defined the orbit parameters
// As for time scale, we will use also a "factory".
final Frame GCRF = FramesFactory.getGCRF();
// Initial orbit
final double sma = 7200.e+3;
final double exc = 0.01;
final double per = sma*(1.-exc);
final double apo = sma*(1.+exc);
final double inc = FastMath.toRadians(98.);
final double pa = FastMath.toRadians(0.);
final double raan = FastMath.toRadians(0.);
final double anm = FastMath.toRadians(0.);
final double MU = Constants.WGS84_EARTH_MU;
final ApsisRadiusParameters par = new ApsisRadiusParameters(per, apo, inc, pa, raan, anm, PositionAngle.MEAN, MU);
final Orbit iniOrbit = new ApsisOrbit(par, GCRF, date);
// We create a spacecratftstate
final SpacecraftState iniState = new SpacecraftState(iniOrbit);
// Initialization of the Runge Kutta integrator with a 2 s step
final double pasRk = 2.;
final FirstOrderIntegrator integrator = new ClassicalRungeKuttaIntegrator(pasRk);
// Initialization of the propagator
final NumericalPropagator propagator = new NumericalPropagator(integrator);
propagator.resetInitialState(iniState);
// Forcing integration using cartesian equations
propagator.setOrbitType(OrbitType.CARTESIAN);
//SPECIFIC
// Adding an attitude law
final AttitudeLaw attitudeLaw = new LofOffset(LOFType.TNW, RotationOrder.ZYX, 0., 0., 0.);
propagator.setAttitudeProvider(attitudeLaw);
//SPECIFIC
// Propagating 100s
final double dt = 100.;
final AbsoluteDate finalDate = date.shiftedBy(dt);
final SpacecraftState finalState = propagator.propagate(finalDate);
final Orbit finalOrbit = finalState.getOrbit();
// Printing new date and true latitude argument
System.out.println();
System.out.println("Initial true latitude argument = "+FastMath.toDegrees(iniOrbit.getLv())+" deg");
System.out.println("New date = "+finalOrbit.getDate().toString(TUC)+" deg");
System.out.println("True latitude argument = "+FastMath.toDegrees(finalOrbit.getLv())+" deg");
// Printing attitude
final double psi = finalState.getAttitude().getRotation().getAngles(RotationOrder.ZYX)[0];
final double teta = finalState.getAttitude().getRotation().getAngles(RotationOrder.ZYX)[1];
final double phi = finalState.getAttitude().getRotation().getAngles(RotationOrder.ZYX)[2];
System.out.println("Psi / GCRF = "+FastMath.toDegrees(psi)+" deg");
System.out.println("Teta / GCRF = "+FastMath.toDegrees(teta)+" deg");
System.out.println("Phi / GCRF = "+FastMath.toDegrees(phi)+" deg");
}
}