/* Copyright 2002-2017 CS Systèmes d'Information
* Licensed to CS Systèmes 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 org.orekit.propagation.sampling;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.Queue;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import org.hipparchus.ode.nonstiff.ClassicalRungeKuttaIntegrator;
import org.hipparchus.util.FastMath;
import org.junit.Before;
import org.junit.Test;
import org.orekit.Utils;
import org.orekit.bodies.CelestialBodyFactory;
import org.orekit.errors.OrekitException;
import org.orekit.frames.FactoryManagedFrame;
import org.orekit.frames.Frame;
import org.orekit.frames.FramesFactory;
import org.orekit.orbits.KeplerianOrbit;
import org.orekit.orbits.OrbitType;
import org.orekit.orbits.PositionAngle;
import org.orekit.propagation.Propagator;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.analytical.KeplerianPropagator;
import org.orekit.propagation.events.DateDetector;
import org.orekit.propagation.events.handlers.ContinueOnEvent;
import org.orekit.propagation.numerical.NumericalPropagator;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.TimeScalesFactory;
import org.orekit.utils.Constants;
import static org.junit.Assert.*;
public class OrekitStepHandlerTest {
@Test
public void testForwardBackwardStep()
throws OrekitException, InterruptedException, ExecutionException {
final AbsoluteDate initialDate = new AbsoluteDate(2014, 01, 01, 00, 00,
00.000,
TimeScalesFactory
.getUTC());
final double mu = CelestialBodyFactory.getEarth().getGM();
FactoryManagedFrame inertialFrame = FramesFactory.getEME2000();
final double propagationTime = 7200.0;// seconds
final double fixedStepSize = 3600; // seconds
final double semimajorAxis = 8000e3; // meters
final double eccentricity = 0.001; // unitless
final double inclination = FastMath.toRadians(15.0);
final double argPerigee = FastMath.toRadians(10.0);
final double raan = FastMath.toRadians(45.0);
final double trueAnomaly = FastMath.toRadians(10.0);
KeplerianOrbit initialOrbit = new KeplerianOrbit(semimajorAxis,
eccentricity,
inclination,
argPerigee, raan,
trueAnomaly,
PositionAngle.TRUE,
inertialFrame,
initialDate, mu);
final Propagator kepler = new KeplerianPropagator(initialOrbit);
kepler.setMasterMode(fixedStepSize, new OrekitFixedStepHandler() {
@Override
public void handleStep(SpacecraftState currentState, boolean isLast) {
}
});
kepler.propagate(initialDate.shiftedBy(propagationTime));
final double stepSizeInSeconds = 120;
final long longestWaitTimeMS = 20;
ExecutorService service = Executors.newSingleThreadExecutor();
for (double elapsedTime = 0; elapsedTime <= propagationTime; elapsedTime += stepSizeInSeconds) {
final double dt = elapsedTime;
Future<SpacecraftState> stateFuture = service
.submit(new Callable<SpacecraftState>() {
public SpacecraftState call()
throws OrekitException {
return kepler.propagate(initialDate.shiftedBy(dt));
}
});
Thread.sleep(longestWaitTimeMS);
assertTrue(stateFuture.isDone());
SpacecraftState finalState = stateFuture.get();
assertNotNull(finalState);
}
}
/**
* Check {@link OrekitStepInterpolator#isPreviousStateInterpolated()} and {@link
* OrekitStepInterpolator#isCurrentStateInterpolated()}.
*
* @throws OrekitException on error.
*/
@Test
public void testIsInterpolated() throws OrekitException {
// setup
NumericalPropagator propagator =
new NumericalPropagator(new ClassicalRungeKuttaIntegrator(60));
AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
Frame eci = FramesFactory.getGCRF();
SpacecraftState ic = new SpacecraftState(new KeplerianOrbit(
6378137 + 500e3, 1e-3, 0, 0, 0, 0,
PositionAngle.TRUE, eci, date, Constants.EIGEN5C_EARTH_MU));
propagator.setInitialState(ic);
propagator.setOrbitType(OrbitType.CARTESIAN);
// detector triggers half way through second step
DateDetector detector =
new DateDetector(date.shiftedBy(90)).withHandler(new ContinueOnEvent<>());
propagator.addEventDetector(detector);
// action and verify
Queue<Boolean> expected =
new ArrayDeque<>(Arrays.asList(false, false, false, true, true, false));
propagator.setMasterMode(new OrekitStepHandler() {
@Override
public void handleStep(OrekitStepInterpolator interpolator, boolean isLast) {
assertEquals(expected.poll(), interpolator.isPreviousStateInterpolated());
assertEquals(expected.poll(), interpolator.isCurrentStateInterpolated());
}
});
final AbsoluteDate end = date.shiftedBy(120);
assertEquals(end, propagator.propagate(end).getDate());
}
@Before
public void setUp()
throws OrekitException {
Utils.setDataRoot("regular-data");
}
}