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 org.orekit.frames; import java.util.ArrayList; 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.MathUtils; 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.TTScale; import org.orekit.time.TimeComponents; import org.orekit.time.TimeScale; import org.orekit.time.TimeScalesFactory; import org.orekit.time.UT1Scale; import org.orekit.utils.Constants; import org.orekit.utils.IERSConventions; import org.orekit.utils.PVCoordinates; public class ITRFEquinoxProviderTest { @Test public void testEquinoxVersusCIO() throws OrekitException { Frame itrfEquinox = FramesFactory.getITRFEquinox(IERSConventions.IERS_1996, true); Frame itrfCIO = FramesFactory.getITRF(IERSConventions.IERS_2010, true); AbsoluteDate start = new AbsoluteDate(2011, 4, 10, TimeScalesFactory.getUTC()); AbsoluteDate end = new AbsoluteDate(2011, 7, 4, TimeScalesFactory.getUTC()); for (AbsoluteDate date = start; date.compareTo(end) < 0; date = date.shiftedBy(10000)) { double angularOffset = itrfEquinox.getTransformTo(itrfCIO, date).getRotation().getAngle(); Assert.assertEquals(0, angularOffset / Constants.ARC_SECONDS_TO_RADIANS, 0.07); } } @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 Utils.setLoaders(IERSConventions.IERS_1996, Utils.buildEOPList(IERSConventions.IERS_1996, new double[][] { { 53098, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }, { 53099, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }, { 53100, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }, { 53101, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }, { 53102, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }, { 53103, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }, { 53104, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }, { 53105, -0.4399619, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN } })); AbsoluteDate t0 = new AbsoluteDate(new DateComponents(2004, 04, 06), new TimeComponents(07, 51, 28.386009), TimeScalesFactory.getUTC()); // ITRF PVCoordinates pvITRF = new PVCoordinates(new Vector3D(-1033479.3830, 7901295.2754, 6380356.5958), new Vector3D(-3225.636520, -2872.451450, 5531.924446)); // GTOD PVCoordinates pvGTOD = new PVCoordinates(new Vector3D(-1033475.0313, 7901305.5856, 6380344.5328), new Vector3D(-3225.632747, -2872.442511, 5531.931288)); Transform t = FramesFactory.getGTOD(IERSConventions.IERS_1996, true) .getTransformTo(FramesFactory.getITRFEquinox(IERSConventions.IERS_1996, true), t0); checkPV(pvITRF, t.transformPVCoordinates(pvGTOD), 8.08e-5, 3.78e-7); } @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_1996, Utils.buildEOPList(IERSConventions.IERS_1996, new double[][] { { 53153, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN }, { 53154, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN }, { 53155, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN }, { 53156, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN }, { 53157, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN }, { 53158, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN }, { 53159, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN }, { 53160, -0.4709050, 0.0000000, -0.083853, 0.467217, -0.053614, -0.004494, Double.NaN, Double.NaN } })); AbsoluteDate t0 = new AbsoluteDate(new DateComponents(2004, 06, 01), TimeComponents.H00, TimeScalesFactory.getUTC()); Transform t = FramesFactory.getGTOD(IERSConventions.IERS_1996, true) .getTransformTo(FramesFactory.getITRFEquinox(IERSConventions.IERS_1996, true), t0); // GTOD PVCoordinates pvGTOD = new PVCoordinates(new Vector3D(24796919.2956, -34115870.9001, 10293.2583), new Vector3D(-0.979178, -1.476540, -0.928772)); // ITRF PVCoordinates pvITRF = new PVCoordinates(new Vector3D(24796919.2915, -34115870.9234, 10226.0621), new Vector3D(-0.979178, -1.476538, -0.928776)); checkPV(pvITRF, t.transformPVCoordinates(pvGTOD), 3.954e-4, 4.69e-7); } @Test public void testSofaCookbook() throws OrekitException { // SOFA cookbook test case: // date 2007 April 05, 12h00m00s.0 UTC // xp +0.0349282 // yp +0.4833163 // UT1 UTC -0s.072073685 // d 1980 -0.0550655 // d 1980 -0.0063580 // dX 2000 +0.0001725 // dY 2000 -0.0002650 // dX 2006 +0.0001750 // dY 2006 -0.0002259 Utils.setLoaders(IERSConventions.IERS_1996, Utils.buildEOPList(IERSConventions.IERS_1996, new double[][] { { 54192, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN }, { 54193, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN }, { 54194, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN }, { 54195, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN }, { 54196, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN }, { 54197, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN }, { 54198, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN }, { 54199, -0.072073685, 1.4020, 0.0349282, 0.4833163, -0.0550666, -0.0063580, Double.NaN, Double.NaN } })); EOPHistory eopHistory = FramesFactory.getEOPHistory(IERSConventions.IERS_1996, true); TimeScale utc = TimeScalesFactory.getUTC(); TTScale tt = TimeScalesFactory.getTT(); UT1Scale ut1 = TimeScalesFactory.getUT1(eopHistory); Frame gcrf = FramesFactory.getGCRF(); Frame itrf = FramesFactory.getITRFEquinox(IERSConventions.IERS_1996, true); Frame gtod = itrf.getParent(); Frame tod = gtod.getParent(); // time scales checks AbsoluteDate date = new AbsoluteDate(new DateComponents(2007, 4, 5), TimeComponents.H12, utc); Assert.assertEquals(0.50075444444444, date.getComponents(tt).getTime().getSecondsInDay() / Constants.JULIAN_DAY, 5.0e-15); Assert.assertEquals(0.499999165813831, date.getComponents(ut1).getTime().getSecondsInDay() / Constants.JULIAN_DAY, 1.0e-15); // sidereal time check double gast = IERSConventions.IERS_1996.getGASTFunction(ut1, eopHistory).value(date).getValue(); Assert.assertEquals(13.412402380740 * 3600 * 1.0e6, radToMicroAS(MathUtils.normalizeAngle(gast, 0)), 25); // nutation/precession/bias matrix check Rotation refNPB = new Rotation( new double[][] { { +0.999998403176203, -0.001639032970562, -0.000712190961847 }, { +0.001639000942243, +0.999998655799521, -0.000045552846624 }, { +0.000712264667137, +0.000044385492226, +0.999999745354454 } }, 1.0e-13); Rotation npb = gcrf.getTransformTo(tod, date).getRotation(); Assert.assertEquals(0.0, radToMicroAS(Rotation.distance(refNPB, npb)), 27.0); // celestial to terrestrial frames matrix, without polar motion Rotation refWithoutPolarMotion = new Rotation( new double[][] { { +0.973104317592265, +0.230363826166883, -0.000703332813776 }, { -0.230363798723533, +0.973104570754697, +0.000120888299841 }, { +0.000712264667137, +0.000044385492226, +0.999999745354454 } }, 1.0e-13); Rotation withoutPM = gcrf.getTransformTo(gtod, date).getRotation(); Assert.assertEquals(0.0, radToMicroAS(Rotation.distance(refWithoutPolarMotion, withoutPM)), 9); // celestial to terrestrial frames matrix, with polar motion Rotation refWithPolarMotion = new Rotation( new double[][] { { +0.973104317712772, +0.230363826174782, -0.000703163477127 }, { -0.230363800391868, +0.973104570648022, +0.000118545116892 }, { +0.000711560100206, +0.000046626645796, +0.999999745754058 } }, 1.0e-13); Rotation withPM = gcrf.getTransformTo(itrf, date).getRotation(); Assert.assertEquals(0.0, radToMicroAS(Rotation.distance(refWithPolarMotion, withPM)), 10); } @Test public void testNROvsEquinoxRealEOP() throws OrekitException { Utils.setDataRoot("regular-data"); checkFrames(FramesFactory.getITRF(IERSConventions.IERS_2010, true), FramesFactory.getITRFEquinox(IERSConventions.IERS_2010, true), 1.7); } @Test public void testNROvsEquinoxNoEOP2010() throws OrekitException { Utils.setLoaders(IERSConventions.IERS_2010, new ArrayList<EOPEntry>()); checkFrames(FramesFactory.getITRF(IERSConventions.IERS_2010, true), FramesFactory.getITRFEquinox(IERSConventions.IERS_2010, true), 1.7); } @Test public void testNROvsEquinoxNoEOP2003() throws OrekitException { Utils.setLoaders(IERSConventions.IERS_2003, new ArrayList<EOPEntry>()); checkFrames(FramesFactory.getITRF(IERSConventions.IERS_2003, true), FramesFactory.getITRFEquinox(IERSConventions.IERS_2003, true), 1.9); } @Test public void testNROvsEquinoxNoEOP1996() throws OrekitException { Utils.setLoaders(IERSConventions.IERS_1996, new ArrayList<EOPEntry>()); checkFrames(FramesFactory.getITRF(IERSConventions.IERS_1996, true), FramesFactory.getITRFEquinox(IERSConventions.IERS_1996, true), 100); } private void checkFrames(Frame frame1, Frame frame2, double toleranceMicroAS) throws OrekitException { AbsoluteDate t0 = new AbsoluteDate(2005, 5, 30, TimeScalesFactory.getUTC()); for (double dt = 0; dt < Constants.JULIAN_YEAR; dt += Constants.JULIAN_DAY / 4) { AbsoluteDate date = t0.shiftedBy(dt); Transform t = FramesFactory.getNonInterpolatingTransform(frame1, frame2, date); Vector3D a = t.getRotation().getAxis(); double delta = FastMath.copySign(radToMicroAS(t.getRotation().getAngle()), a.getZ()); Assert.assertEquals(0.0, delta, toleranceMicroAS); } } @Before public void setUp() { Utils.setDataRoot("rapid-data-columns"); } 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); } double radToMicroAS(double deltaRad) { return deltaRad * 1.0e6 / Constants.ARC_SECONDS_TO_RADIANS; } }