/* 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.frames;
import org.hipparchus.geometry.euclidean.threed.Vector3D;
import org.hipparchus.util.FastMath;
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.TimeScalesFactory;
import org.orekit.utils.Constants;
import org.orekit.utils.IERSConventions;
public class HelmertTransformationTest {
@Test
public void testHelmert20052008() throws OrekitException {
Frame itrf2008 = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
Frame itrf2005 =
HelmertTransformation.Predefined.ITRF_2008_TO_ITRF_2005.createTransformedITRF(itrf2008, "2005");
Vector3D pos2005 = new Vector3D(1234567.8, 2345678.9, 3456789.0);
// check the Helmert transformation as per http://itrf.ign.fr/ITRF_solutions/2008/tp_08-05.php
AbsoluteDate date = new AbsoluteDate(2005, 1, 1, 12, 0, 0, TimeScalesFactory.getTT());
Vector3D pos2008 = itrf2005.getTransformTo(itrf2008, date).transformPosition(pos2005);
Vector3D generalOffset = pos2005.subtract(pos2008);
Vector3D linearOffset = computeOffsetLinearly(-0.5, -0.9, -4.7, 0.000, 0.000, 0.000,
0.3, 0.0, 0.0, 0.000, 0.000, 0.000,
pos2005, 0.0);
Vector3D error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), 2.0e-13 * pos2005.getNorm());
date = date.shiftedBy(Constants.JULIAN_YEAR);
pos2008 = itrf2005.getTransformTo(itrf2008, date).transformPosition(pos2005);
generalOffset = pos2005.subtract(pos2008);
linearOffset = computeOffsetLinearly(-0.5, -0.9, -4.7, 0.000, 0.000, 0.000,
0.3, 0.0, 0.0, 0.000, 0.000, 0.000,
pos2005, 1.0);
error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), 2.0e-13 * pos2005.getNorm());
}
@Test
public void testHelmert20002005() throws OrekitException {
Frame itrf2008 = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
Frame itrf2000 =
HelmertTransformation.Predefined.ITRF_2008_TO_ITRF_2000.createTransformedITRF(itrf2008, "2000");
Frame itrf2005 =
HelmertTransformation.Predefined.ITRF_2008_TO_ITRF_2005.createTransformedITRF(itrf2008, "2005");
Vector3D pos2000 = new Vector3D(1234567.8, 2345678.9, 3456789.0);
// check the Helmert transformation as per http://itrf.ign.fr/ITRF_solutions/2005/tp_05-00.php
AbsoluteDate date = AbsoluteDate.J2000_EPOCH;
Vector3D pos2005 = itrf2000.getTransformTo(itrf2005, date).transformPosition(pos2000);
Vector3D generalOffset = pos2000.subtract(pos2005);
Vector3D linearOffset = computeOffsetLinearly( 0.1, -0.8, -5.8, 0.000, 0.000, 0.000,
-0.2, 0.1, -1.8, 0.000, 0.000, 0.000,
pos2000, 0.0);
Vector3D error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), FastMath.ulp(pos2000.getNorm()));
date = date.shiftedBy(Constants.JULIAN_YEAR);
pos2005 = itrf2000.getTransformTo(itrf2005, date).transformPosition(pos2000);
generalOffset = pos2000.subtract(pos2005);
linearOffset = computeOffsetLinearly( 0.1, -0.8, -5.8, 0.000, 0.000, 0.000,
-0.2, 0.1, -1.8, 0.000, 0.000, 0.000,
pos2000, 1.0);
error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), FastMath.ulp(pos2000.getNorm()));
}
@Test
public void testHelmert19972000() throws OrekitException {
Frame itrf2008 = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
Frame itrf2000 =
HelmertTransformation.Predefined.ITRF_2008_TO_ITRF_2000.createTransformedITRF(itrf2008, "2000");
Frame itrf97 =
HelmertTransformation.Predefined.ITRF_2008_TO_ITRF_97.createTransformedITRF(itrf2008, "97");
Vector3D pos97 = new Vector3D(1234567.8, 2345678.9, 3456789.0);
// check the Helmert transformation as per ftp://itrf.ensg.ign.fr/pub/itrf/ITRF.TP
AbsoluteDate date = new AbsoluteDate(1997, 1, 1, 12, 0, 0, TimeScalesFactory.getTT());
Vector3D pos2000 = itrf97.getTransformTo(itrf2000, date).transformPosition(pos97);
Vector3D generalOffset = pos97.subtract(pos2000);
Vector3D linearOffset = computeOffsetLinearly( 6.7, 6.1, -18.5, 0.000, 0.000, 0.000,
0.0, -0.6, -1.4, 0.000, 0.000, 0.002,
pos2000, 0.0);
Vector3D error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), 2.0e-11 * pos97.getNorm());
date = date.shiftedBy(Constants.JULIAN_YEAR);
pos2000 = itrf97.getTransformTo(itrf2000, date).transformPosition(pos97);
generalOffset = pos97.subtract(pos2000);
linearOffset = computeOffsetLinearly( 6.7, 6.1, -18.5, 0.000, 0.000, 0.000,
0.0, -0.6, -1.4, 0.000, 0.000, 0.002,
pos2000, 1.0);
error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), 6.0e-11 * pos97.getNorm());
}
@Test
public void testHelmert19932000() throws OrekitException {
Frame itrf2008 = FramesFactory.getITRF(IERSConventions.IERS_2010, true);
Frame itrf2000 =
HelmertTransformation.Predefined.ITRF_2008_TO_ITRF_2000.createTransformedITRF(itrf2008, "2000");
Frame itrf93 =
HelmertTransformation.Predefined.ITRF_2008_TO_ITRF_93.createTransformedITRF(itrf2008, "93");
Vector3D pos93 = new Vector3D(1234567.8, 2345678.9, 3456789.0);
// check the Helmert transformation as per ftp://itrf.ensg.ign.fr/pub/itrf/ITRF.TP
AbsoluteDate date = new AbsoluteDate(1988, 1, 1, 12, 0, 0, TimeScalesFactory.getTT());
Vector3D pos2000 = itrf93.getTransformTo(itrf2000, date).transformPosition(pos93);
Vector3D generalOffset = pos93.subtract(pos2000);
Vector3D linearOffset = computeOffsetLinearly(12.7, 6.5, -20.9, -0.39, 0.80, -1.14,
-2.9, -0.2, -0.6, -0.11, -0.19, 0.07,
pos2000, 0.0);
Vector3D error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), FastMath.ulp(pos93.getNorm()));
date = date.shiftedBy(Constants.JULIAN_YEAR);
pos2000 = itrf93.getTransformTo(itrf2000, date).transformPosition(pos93);
generalOffset = pos93.subtract(pos2000);
linearOffset = computeOffsetLinearly(12.7, 6.5, -20.9, -0.39, 0.80, -1.14,
-2.9, -0.2, -0.6, -0.11, -0.19, 0.07,
pos2000, 1.0);
error = generalOffset.subtract(linearOffset);
Assert.assertEquals(0.0, error.getNorm(), FastMath.ulp(pos93.getNorm()));
}
private Vector3D computeOffsetLinearly(final double t1, final double t2, final double t3,
final double r1, final double r2, final double r3,
final double t1Dot, final double t2Dot, final double t3Dot,
final double r1Dot, final double r2Dot, final double r3Dot,
final Vector3D p, final double dt) {
double t1U = (t1 + dt * t1Dot) * 1.0e-3;
double t2U = (t2 + dt * t2Dot) * 1.0e-3;
double t3U = (t3 + dt * t3Dot) * 1.0e-3;
double r1U = FastMath.toRadians((r1 + dt * r1Dot) / 3.6e6);
double r2U = FastMath.toRadians((r2 + dt * r2Dot) / 3.6e6);
double r3U = FastMath.toRadians((r3 + dt * r3Dot) / 3.6e6);
return new Vector3D(t1U - r3U * p.getY() + r2U * p.getZ(),
t2U + r3U * p.getX() - r1U * p.getZ(),
t3U - r2U * p.getX() + r1U * p.getY());
}
@Before
public void setUp() {
Utils.setDataRoot("compressed-data");
}
}