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.forces.drag; import org.apache.commons.math3.geometry.euclidean.threed.Vector3D; import org.apache.commons.math3.ode.nonstiff.DormandPrince853Integrator; import org.apache.commons.math3.util.FastMath; import org.junit.Before; import org.junit.Test; import org.orekit.Utils; import org.orekit.bodies.CelestialBodyFactory; import org.orekit.bodies.OneAxisEllipsoid; import org.orekit.errors.OrekitException; import org.orekit.forces.AbstractForceModelTest; import org.orekit.forces.BoxAndSolarArraySpacecraft; import org.orekit.forces.SphericalSpacecraft; import org.orekit.frames.FramesFactory; import org.orekit.orbits.CartesianOrbit; import org.orekit.orbits.KeplerianOrbit; import org.orekit.orbits.Orbit; import org.orekit.orbits.OrbitType; import org.orekit.orbits.PositionAngle; import org.orekit.propagation.SpacecraftState; import org.orekit.propagation.numerical.NumericalPropagator; import org.orekit.time.AbsoluteDate; import org.orekit.time.DateComponents; import org.orekit.time.TimeComponents; import org.orekit.time.TimeScalesFactory; import org.orekit.utils.Constants; import org.orekit.utils.IERSConventions; import org.orekit.utils.PVCoordinates; public class DragForceTest extends AbstractForceModelTest { @Test public void testParameterDerivativeSphere() throws OrekitException { final Vector3D pos = new Vector3D(6.46885878304673824e+06, -1.88050918456274318e+06, -1.32931592294715829e+04); final Vector3D vel = new Vector3D(2.14718074509906819e+03, 7.38239351251748485e+03, -1.14097953925384523e+01); final SpacecraftState state = new SpacecraftState(new CartesianOrbit(new PVCoordinates(pos, vel), FramesFactory.getGCRF(), new AbsoluteDate(2003, 3, 5, 0, 24, 0.0, TimeScalesFactory.getTAI()), Constants.EIGEN5C_EARTH_MU)); final DragForce forceModel = new DragForce(new HarrisPriester(CelestialBodyFactory.getSun(), new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true))), new SphericalSpacecraft(2.5, 1.2, 0.7, 0.2)); checkParameterDerivative(state, forceModel, DragSensitive.DRAG_COEFFICIENT, 1.0e-4, 2.0e-12); } @Test public void testStateJacobianSphere() throws OrekitException { // initialization AbsoluteDate date = new AbsoluteDate(new DateComponents(2003, 03, 01), new TimeComponents(13, 59, 27.816), TimeScalesFactory.getUTC()); double i = FastMath.toRadians(98.7); double omega = FastMath.toRadians(93.0); double OMEGA = FastMath.toRadians(15.0 * 22.5); Orbit orbit = new KeplerianOrbit(7201009.7124401, 1e-3, i, omega, OMEGA, 0, PositionAngle.MEAN, FramesFactory.getEME2000(), date, Constants.EIGEN5C_EARTH_MU); OrbitType integrationType = OrbitType.CARTESIAN; double[][] tolerances = NumericalPropagator.tolerances(0.01, orbit, integrationType); NumericalPropagator propagator = new NumericalPropagator( new DormandPrince853Integrator(1.0e-3, 120, tolerances[0], tolerances[1])); propagator.setOrbitType(integrationType); final DragForce forceModel = new DragForce(new HarrisPriester(CelestialBodyFactory.getSun(), new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true))), new SphericalSpacecraft(2.5, 1.2, 0.7, 0.2)); propagator.addForceModel(forceModel); SpacecraftState state0 = new SpacecraftState(orbit); checkStateJacobian(propagator, state0, date.shiftedBy(3.5 * 3600.0), 1e3, tolerances[0], 3.0e-4); } @Test public void testParameterDerivativeBox() throws OrekitException { final Vector3D pos = new Vector3D(6.46885878304673824e+06, -1.88050918456274318e+06, -1.32931592294715829e+04); final Vector3D vel = new Vector3D(2.14718074509906819e+03, 7.38239351251748485e+03, -1.14097953925384523e+01); final SpacecraftState state = new SpacecraftState(new CartesianOrbit(new PVCoordinates(pos, vel), FramesFactory.getGCRF(), new AbsoluteDate(2003, 3, 5, 0, 24, 0.0, TimeScalesFactory.getTAI()), Constants.EIGEN5C_EARTH_MU)); final DragForce forceModel = new DragForce(new HarrisPriester(CelestialBodyFactory.getSun(), new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true))), new BoxAndSolarArraySpacecraft(1.5, 2.0, 1.8, CelestialBodyFactory.getSun(), 20.0, Vector3D.PLUS_J, 1.2, 0.7, 0.2)); checkParameterDerivative(state, forceModel, DragSensitive.DRAG_COEFFICIENT, 1.0e-4, 2.0e-12); } @Test public void testStateJacobianBox() throws OrekitException { // initialization AbsoluteDate date = new AbsoluteDate(new DateComponents(2003, 03, 01), new TimeComponents(13, 59, 27.816), TimeScalesFactory.getUTC()); double i = FastMath.toRadians(98.7); double omega = FastMath.toRadians(93.0); double OMEGA = FastMath.toRadians(15.0 * 22.5); Orbit orbit = new KeplerianOrbit(7201009.7124401, 1e-3, i, omega, OMEGA, 0, PositionAngle.MEAN, FramesFactory.getEME2000(), date, Constants.EIGEN5C_EARTH_MU); OrbitType integrationType = OrbitType.CARTESIAN; double[][] tolerances = NumericalPropagator.tolerances(0.01, orbit, integrationType); NumericalPropagator propagator = new NumericalPropagator( new DormandPrince853Integrator(1.0e-3, 120, tolerances[0], tolerances[1])); propagator.setOrbitType(integrationType); final DragForce forceModel = new DragForce(new HarrisPriester(CelestialBodyFactory.getSun(), new OneAxisEllipsoid(Constants.WGS84_EARTH_EQUATORIAL_RADIUS, Constants.WGS84_EARTH_FLATTENING, FramesFactory.getITRF(IERSConventions.IERS_2010, true))), new BoxAndSolarArraySpacecraft(1.5, 2.0, 1.8, CelestialBodyFactory.getSun(), 20.0, Vector3D.PLUS_J, 1.2, 0.7, 0.2)); propagator.addForceModel(forceModel); SpacecraftState state0 = new SpacecraftState(orbit); checkStateJacobian(propagator, state0, date.shiftedBy(3.5 * 3600.0), 1e3, tolerances[0], 2.0e-3); } @Before public void setUp() throws OrekitException { Utils.setDataRoot("regular-data"); } }