Java tutorial
/* 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 org.orekit.frames; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.util.ArrayList; import java.util.List; import java.util.concurrent.Callable; import java.util.concurrent.ExecutionException; import java.util.concurrent.Executors; import java.util.concurrent.Future; import org.apache.commons.math3.geometry.euclidean.threed.Rotation; import org.apache.commons.math3.geometry.euclidean.threed.Vector3D; import org.apache.commons.math3.util.FastMath; import org.apache.commons.math3.util.Precision; import org.junit.Assert; import org.junit.Before; import org.junit.Test; import org.orekit.Utils; import org.orekit.errors.OrekitException; import org.orekit.time.AbsoluteDate; import org.orekit.time.DateComponents; import org.orekit.time.TimeComponents; import org.orekit.time.TimeScalesFactory; import org.orekit.utils.AngularCoordinates; import org.orekit.utils.IERSConventions; import org.orekit.utils.PVCoordinates; /** * Unit tests for {@link TIRFProvider}. * * @author Evan Ward */ public class TIRFProviderTest { @Test public void testAASReferenceLEO() throws OrekitException { // this reference test has been extracted from the following paper: // Implementation Issues Surrounding the New IAU Reference Systems for Astrodynamics // David A. Vallado, John H. Seago, P. Kenneth Seidelmann // http://www.centerforspace.com/downloads/files/pubs/AAS-06-134.pdf // Reference position & velocity from : "Fundamentals of Astrodynamics and Applications", Third edition, David A. Vallado Utils.setLoaders(IERSConventions.IERS_2010, Utils.buildEOPList(IERSConventions.IERS_2010, new double[][] { { 53098, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53099, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53100, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53101, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53102, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53103, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53104, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53105, -0.4399619, 0.0015563, -0.140682, 0.333309, Double.NaN, Double.NaN, -0.000199, -0.000252 } })); AbsoluteDate t0 = new AbsoluteDate(new DateComponents(2004, 04, 06), new TimeComponents(07, 51, 28.386009), TimeScalesFactory.getUTC()); // Positions LEO Frame itrfA = FramesFactory.getITRF(IERSConventions.IERS_2010, true); PVCoordinates pvITRF = new PVCoordinates(new Vector3D(-1033479.3830, 7901295.2754, 6380356.5958), new Vector3D(-3225.636520, -2872.451450, 5531.924446)); // Reference coordinates Frame tirf = FramesFactory.getTIRF(IERSConventions.IERS_2010); PVCoordinates pvTIRF = new PVCoordinates(new Vector3D(-1033475.0312, 7901305.5856, 6380344.5328), new Vector3D(-3225.632747, -2872.442511, 5531.931288)); checkPV(pvTIRF, itrfA.getTransformTo(tirf, t0).transformPVCoordinates(pvITRF), 6.379e-5, 3.78e-7); Frame cirf = FramesFactory.getCIRF(IERSConventions.IERS_2010, true); PVCoordinates pvCIRF = new PVCoordinates(new Vector3D(5100018.4047, 6122786.3648, 6380344.5328), new Vector3D(-4745.380330, 790.341453, 5531.931288)); checkPV(pvCIRF, tirf.getTransformTo(cirf, t0).transformPVCoordinates(pvTIRF), 8.59e-3, 4.65e-6); } @Test public void testAASReferenceGEO() throws OrekitException { // this reference test has been extracted from the following paper: // Implementation Issues Surrounding the New IAU Reference Systems for Astrodynamics // David A. Vallado, John H. Seago, P. Kenneth Seidelmann // http://www.centerforspace.com/downloads/files/pubs/AAS-06-134.pdf Utils.setLoaders(IERSConventions.IERS_2010, Utils.buildEOPList(IERSConventions.IERS_2010, new double[][] { { 53153, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53154, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53155, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53156, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53157, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53158, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53159, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 }, { 53160, -0.4709050, 0.0000000, -0.083853, 0.467217, Double.NaN, Double.NaN, -0.000199, -0.000252 } })); AbsoluteDate t0 = new AbsoluteDate(new DateComponents(2004, 06, 01), TimeComponents.H00, TimeScalesFactory.getUTC()); // Positions GEO Frame itrfA = FramesFactory.getITRF(IERSConventions.IERS_2010, true); PVCoordinates pvITRF = new PVCoordinates(new Vector3D(24796919.2915, -34115870.9234, 10226.0621), new Vector3D(-0.979178, -1.476538, -0.928776)); Frame tirf = FramesFactory.getTIRF(IERSConventions.IERS_2010); PVCoordinates pvTIRF = new PVCoordinates(new Vector3D(24796919.2953, -34115870.9004, 10293.2583), new Vector3D(-0.979178, -1.476540, -0.928772)); checkPV(pvTIRF, itrfA.getTransformTo(tirf, t0).transformPVCoordinates(pvITRF), 5.697e-5, 4.69e-7); Frame cirf = FramesFactory.getCIRF(IERSConventions.IERS_2010, true); PVCoordinates pvCIRF = new PVCoordinates(new Vector3D(-40588158.1236, -11462167.0709, 10293.2583), new Vector3D(834.787843, -2958.305669, -0.928772)); checkPV(pvCIRF, tirf.getTransformTo(cirf, t0).transformPVCoordinates(pvTIRF), 0.0505, 3.60e-6); } @Test public void testSerialization() throws OrekitException, IOException, ClassNotFoundException { TIRFProvider provider = new TIRFProvider(FramesFactory.getEOPHistory(IERSConventions.IERS_2010, true)); ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(bos); oos.writeObject(provider); Assert.assertTrue(bos.size() > 280000); Assert.assertTrue(bos.size() < 285000); ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray()); ObjectInputStream ois = new ObjectInputStream(bis); TIRFProvider deserialized = (TIRFProvider) ois.readObject(); for (int i = 0; i < FastMath.min(100, provider.getEOPHistory().getEntries().size()); ++i) { AbsoluteDate date = provider.getEOPHistory().getEntries().get(i).getDate(); Transform expectedIdentity = new Transform(date, provider.getTransform(date).getInverse(), deserialized.getTransform(date)); Assert.assertEquals(0.0, expectedIdentity.getTranslation().getNorm(), 1.0e-15); Assert.assertEquals(0.0, expectedIdentity.getRotation().getAngle(), 1.0e-15); } } /** * Checks that {@link TIRFProvider#getTransform(AbsoluteDate)} is thread safe. */ @Test public void testConcurrentGetTransform() throws OrekitException, InterruptedException, ExecutionException { // subject under test final TIRFProvider tirf = new TIRFProvider(FramesFactory.getEOPHistory(IERSConventions.IERS_2010, false)); // arbitrary date final AbsoluteDate start = new AbsoluteDate("2009-09-19T23:59:45.000", TimeScalesFactory.getUTC()); // in seconds = 15min final double timeStep = 300; // the number of possible concurrent threads final int nJobs = 24; // the number of calculations per thread final int nPerJob = 1000; // tolerance of comparisons final double absTol = Precision.EPSILON; // the expected result final List<Transform> expecteds = new ArrayList<Transform>(); for (int j = 0; j < nPerJob; j++) { final AbsoluteDate date = start.shiftedBy(timeStep * j); // action final Transform expected = tirf.getTransform(date); // verify expecteds.add(expected); } // build jobs for concurrent execution final List<Callable<Boolean>> jobs = new ArrayList<Callable<Boolean>>(); for (int i = 0; i < nJobs; i++) { jobs.add(new Callable<Boolean>() { public Boolean call() throws Exception { for (int j = 0; j < nPerJob; j++) { final AbsoluteDate date = start.shiftedBy(timeStep * j); // action final Transform actual = tirf.getTransform(date); // verify assertTransformEquals(expecteds.get(j), actual, absTol); } return true; } }); } // run the jobs runConcurrentlyAndCheck(jobs, nJobs); } /** * Runs several jobs at concurrently in the given number of threads. * * @param jobs * the jobs to execute * @param threads * the size of the thread pool */ private static void runConcurrentlyAndCheck(List<Callable<Boolean>> jobs, int threads) throws InterruptedException, ExecutionException { // action final List<Future<Boolean>> futures = Executors.newFixedThreadPool(threads).invokeAll(jobs); // verify - necessary to throw AssertionErrors from the Callable for (Future<Boolean> future : futures) { Assert.assertEquals(true, future.get()); } } /** * Check the two {@link Transform}s are the same to within an absolute tolerance. */ private static void assertTransformEquals(Transform expected, Transform actual, double absTol) { final AngularCoordinates expectedAngular = expected.getAngular(); final AngularCoordinates actualAngular = actual.getAngular(); final Rotation expectedRotation = expectedAngular.getRotation(); final Rotation actualRotation = actualAngular.getRotation(); final PVCoordinates expectedPV = expected.getCartesian(); final PVCoordinates actualPV = actual.getCartesian(); // transform Assert.assertEquals(Rotation.distance(actualRotation, expectedRotation), 0, absTol); Assert.assertEquals(expectedAngular.getRotationRate(), actualAngular.getRotationRate()); Assert.assertEquals(expectedPV.getPosition(), actualPV.getPosition()); Assert.assertEquals(expectedPV.getVelocity(), actualPV.getVelocity()); } @Before public void setUp() { Utils.setDataRoot("compressed-data"); } private void checkPV(PVCoordinates reference, PVCoordinates result, double expectedPositionError, double expectedVelocityError) { Vector3D dP = result.getPosition().subtract(reference.getPosition()); Vector3D dV = result.getVelocity().subtract(reference.getVelocity()); Assert.assertEquals(expectedPositionError, dP.getNorm(), 0.01 * expectedPositionError); Assert.assertEquals(expectedVelocityError, dV.getNorm(), 0.01 * expectedVelocityError); } }