/* 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.time;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.orekit.Utils;
import org.orekit.errors.OrekitException;
import org.orekit.utils.Constants;
import org.orekit.utils.IERSConventions;
public class TCGScaleTest {
@Test
public void testRatio() {
TimeScale scale = TimeScalesFactory.getTCG();
Assert.assertEquals("TCG", scale.toString());
final double dtTT = 1e6;
final AbsoluteDate t1 = AbsoluteDate.J2000_EPOCH;
final AbsoluteDate t2 = t1.shiftedBy(dtTT);
final double dtTCG = dtTT + scale.offsetFromTAI(t2) - scale.offsetFromTAI(t1);
Assert.assertEquals(1 - 6.969290134e-10, dtTT / dtTCG, 1.0e-15);
}
@Test
public void testSymmetry() {
TimeScale scale = TimeScalesFactory.getTCG();
for (double dt = -10000; dt < 10000; dt += 123.456789) {
AbsoluteDate date = AbsoluteDate.J2000_EPOCH.shiftedBy(dt * Constants.JULIAN_DAY);
double dt1 = scale.offsetFromTAI(date);
DateTimeComponents components = date.getComponents(scale);
double dt2 = scale.offsetToTAI(components.getDate(), components.getTime());
Assert.assertEquals( 0.0, dt1 + dt2, 1.0e-10);
}
}
@Test
public void testDuringLeap() throws OrekitException {
final TimeScale utc = TimeScalesFactory.getUTC();
final TimeScale scale = TimeScalesFactory.getTCG();
final AbsoluteDate before = new AbsoluteDate(new DateComponents(1983, 06, 30),
new TimeComponents(23, 59, 59),
utc);
final AbsoluteDate during = before.shiftedBy(1.25);
Assert.assertEquals(61, utc.minuteDuration(during));
Assert.assertEquals(1.0, utc.getLeap(during), 1.0e-10);
Assert.assertEquals(60, scale.minuteDuration(during));
Assert.assertEquals(0.0, scale.getLeap(during), 1.0e-10);
}
@Test
public void testReference() throws OrekitException {
DateComponents referenceDate = new DateComponents(1977, 01, 01);
TimeComponents thirtyTwo = new TimeComponents(0, 0, 32.184);
AbsoluteDate ttRef = new AbsoluteDate(referenceDate, thirtyTwo, TimeScalesFactory.getTT());
AbsoluteDate tcgRef = new AbsoluteDate(referenceDate, thirtyTwo, TimeScalesFactory.getTCG());
AbsoluteDate taiRef = new AbsoluteDate(referenceDate, TimeComponents.H00, TimeScalesFactory.getTAI());
AbsoluteDate utcRef = new AbsoluteDate(new DateComponents(1976, 12, 31),
new TimeComponents(23, 59, 45),
TimeScalesFactory.getUTC());
Assert.assertEquals(0, ttRef.durationFrom(tcgRef), 1.0e-15);
Assert.assertEquals(0, ttRef.durationFrom(taiRef), 1.0e-15);
Assert.assertEquals(0, ttRef.durationFrom(utcRef), 1.0e-15);
}
@Test
public void testSofa() {
TimeScale tt = TimeScalesFactory.getTT();
AbsoluteDate date = new AbsoluteDate(2006, 1, 15, 21, 25, 10.5000096, tt);
double delta = TimeScalesFactory.getTCG().offsetFromTAI(date) - tt.offsetFromTAI(date);
Assert.assertEquals(Constants.JULIAN_DAY * (0.8924900312508587113 - 0.892482639), delta, 5.0e-10);
}
@Test
public void testAAS06134() 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
// Note that the dUT1 here is -0.439962, whereas it is -0.4399619 in the book
Utils.setLoaders(IERSConventions.IERS_1996,
Utils.buildEOPList(IERSConventions.IERS_1996, new double[][] {
{ 53098, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
{ 53099, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
{ 53100, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
{ 53101, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
{ 53102, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
{ 53103, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
{ 53104, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN },
{ 53105, -0.439962, 0.0015563, -0.140682, 0.333309, -0.052195, -0.003875, Double.NaN, Double.NaN }
}));
AbsoluteDate date =
new AbsoluteDate(2004, 4, 6, 7, 51, 28.386009, TimeScalesFactory.getUTC());
DateTimeComponents components = date.getComponents(TimeScalesFactory.getTCG());
Assert.assertEquals(2004, components.getDate().getYear());
Assert.assertEquals( 4, components.getDate().getMonth());
Assert.assertEquals( 6, components.getDate().getDay());
Assert.assertEquals( 7, components.getTime().getHour());
Assert.assertEquals( 52, components.getTime().getMinute());
Assert.assertEquals( 33.1695861742, components.getTime().getSecond(), 1.0e-10);
}
@Before
public void setUp() {
Utils.setDataRoot("regular-data");
}
}