Java tutorial
/* Copyright 2002-2015 CS Systmes d'Information * Licensed to CS Systmes d'Information (CS) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * CS licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package fr.cs.examples.propagation; import java.util.Locale; import org.apache.commons.math3.ode.nonstiff.AdaptiveStepsizeIntegrator; import org.apache.commons.math3.ode.nonstiff.DormandPrince853Integrator; import org.apache.commons.math3.util.FastMath; import org.orekit.errors.OrekitException; import org.orekit.forces.ForceModel; import org.orekit.forces.gravity.HolmesFeatherstoneAttractionModel; import org.orekit.forces.gravity.potential.GravityFieldFactory; import org.orekit.forces.gravity.potential.NormalizedSphericalHarmonicsProvider; import org.orekit.frames.Frame; import org.orekit.frames.FramesFactory; import org.orekit.orbits.KeplerianOrbit; import org.orekit.orbits.Orbit; import org.orekit.orbits.OrbitType; import org.orekit.orbits.PositionAngle; import org.orekit.propagation.SpacecraftState; import org.orekit.propagation.numerical.NumericalPropagator; import org.orekit.propagation.sampling.OrekitFixedStepHandler; import org.orekit.time.AbsoluteDate; import org.orekit.time.TimeScalesFactory; import org.orekit.utils.IERSConventions; import fr.cs.examples.Autoconfiguration; /** Orekit tutorial for master mode propagation. * <p>This tutorial shows the interest of the master mode which hides the complex * internal mechanic of the propagation and just fulfills the user main needs.<p> * @author Fabien Maussion * @author Pascal Parraud */ public class MasterMode { /** Program entry point. * @param args program arguments (unused here) */ public static void main(String[] args) { try { // configure Orekit Autoconfiguration.configureOrekit(); // gravitation coefficient double mu = 3.986004415e+14; // inertial frame Frame inertialFrame = FramesFactory.getEME2000(); // Initial date AbsoluteDate initialDate = new AbsoluteDate(2004, 01, 01, 23, 30, 00.000, TimeScalesFactory.getUTC()); // Initial orbit double a = 24396159; // semi major axis in meters double e = 0.72831215; // eccentricity double i = FastMath.toRadians(7); // inclination double omega = FastMath.toRadians(180); // perigee argument double raan = FastMath.toRadians(261); // right ascention of ascending node double lM = 0; // mean anomaly Orbit initialOrbit = new KeplerianOrbit(a, e, i, omega, raan, lM, PositionAngle.MEAN, inertialFrame, initialDate, mu); // Initial state definition SpacecraftState initialState = new SpacecraftState(initialOrbit); // Adaptive step integrator with a minimum step of 0.001 and a maximum step of 1000 final double minStep = 0.001; final double maxstep = 1000.0; final double positionTolerance = 10.0; final OrbitType propagationType = OrbitType.KEPLERIAN; final double[][] tolerances = NumericalPropagator.tolerances(positionTolerance, initialOrbit, propagationType); AdaptiveStepsizeIntegrator integrator = new DormandPrince853Integrator(minStep, maxstep, tolerances[0], tolerances[1]); // Propagator NumericalPropagator propagator = new NumericalPropagator(integrator); propagator.setOrbitType(propagationType); // Force Model (reduced to perturbing gravity field) final NormalizedSphericalHarmonicsProvider provider = GravityFieldFactory.getNormalizedProvider(10, 10); ForceModel holmesFeatherstone = new HolmesFeatherstoneAttractionModel( FramesFactory.getITRF(IERSConventions.IERS_2010, true), provider); // Add force model to the propagator propagator.addForceModel(holmesFeatherstone); // Set up initial state in the propagator propagator.setInitialState(initialState); // Set up operating mode for the propagator as master mode // with fixed step and specialized step handler propagator.setMasterMode(60., new TutorialStepHandler()); // Extrapolate from the initial to the final date SpacecraftState finalState = propagator.propagate(initialDate.shiftedBy(630.)); KeplerianOrbit o = (KeplerianOrbit) OrbitType.KEPLERIAN.convertType(finalState.getOrbit()); System.out.format(Locale.US, "Final state:%n%s %12.3f %10.8f %10.6f %10.6f %10.6f %10.6f%n", finalState.getDate(), o.getA(), o.getE(), FastMath.toDegrees(o.getI()), FastMath.toDegrees(o.getPerigeeArgument()), FastMath.toDegrees(o.getRightAscensionOfAscendingNode()), FastMath.toDegrees(o.getTrueAnomaly())); } catch (OrekitException oe) { System.err.println(oe.getMessage()); } } /** Specialized step handler. * <p>This class extends the step handler in order to print on the output stream at the given step.<p> * @author Pascal Parraud */ private static class TutorialStepHandler implements OrekitFixedStepHandler { private TutorialStepHandler() { //private constructor } public void init(final SpacecraftState s0, final AbsoluteDate t) { System.out.println(" date a e" + " i \u03c9 \u03a9" + " \u03bd"); } public void handleStep(SpacecraftState currentState, boolean isLast) { KeplerianOrbit o = (KeplerianOrbit) OrbitType.KEPLERIAN.convertType(currentState.getOrbit()); System.out.format(Locale.US, "%s %12.3f %10.8f %10.6f %10.6f %10.6f %10.6f%n", currentState.getDate(), o.getA(), o.getE(), FastMath.toDegrees(o.getI()), FastMath.toDegrees(o.getPerigeeArgument()), FastMath.toDegrees(o.getRightAscensionOfAscendingNode()), FastMath.toDegrees(o.getTrueAnomaly())); if (isLast) { System.out.println("this was the last step "); System.out.println(); } } } }