PV.java
- /* 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.estimation.measurements;
- import java.util.Arrays;
- import org.hipparchus.geometry.euclidean.threed.Vector3D;
- import org.orekit.errors.OrekitException;
- import org.orekit.propagation.SpacecraftState;
- import org.orekit.time.AbsoluteDate;
- import org.orekit.utils.TimeStampedPVCoordinates;
- /** Class modeling a position-velocity state.
- * @author Luc Maisonobe
- * @since 8.0
- */
- public class PV extends AbstractMeasurement<PV> {
- /** Identity matrix, for states derivatives. */
- private static final double[][] IDENTITY = new double[][] {
- {
- 1, 0, 0, 0, 0, 0
- }, {
- 0, 1, 0, 0, 0, 0
- }, {
- 0, 0, 1, 0, 0, 0
- }, {
- 0, 0, 0, 1, 0, 0
- }, {
- 0, 0, 0, 0, 1, 0
- }, {
- 0, 0, 0, 0, 0, 1
- }
- };
- /** Simple constructor.
- * <p>
- * The measurement must be in the orbit propagation frame.
- * </p>
- * <p>
- * This constructor uses 0 as the index of the propagator related
- * to this measurement, thus being well suited for mono-satellite
- * orbit determination.
- * </p>
- * @param date date of the measurement
- * @param position position
- * @param velocity velocity
- * @param sigmaPosition theoretical standard deviation on position components
- * @param sigmaVelocity theoretical standard deviation on velocity components
- * @param baseWeight base weight
- */
- public PV(final AbsoluteDate date, final Vector3D position, final Vector3D velocity,
- final double sigmaPosition, final double sigmaVelocity, final double baseWeight) {
- this(date, position, velocity, sigmaPosition, sigmaVelocity, baseWeight, 0);
- }
- /** Simple constructor.
- * <p>
- * The measurement must be in the orbit propagation frame.
- * </p>
- * @param date date of the measurement
- * @param position position
- * @param velocity velocity
- * @param sigmaPosition theoretical standard deviation on position components
- * @param sigmaVelocity theoretical standard deviation on velocity components
- * @param baseWeight base weight
- * @param propagatorIndex index of the propagator related to this measurement
- * @since 9.0
- */
- public PV(final AbsoluteDate date, final Vector3D position, final Vector3D velocity,
- final double sigmaPosition, final double sigmaVelocity, final double baseWeight,
- final int propagatorIndex) {
- super(date,
- new double[] {
- position.getX(), position.getY(), position.getZ(),
- velocity.getX(), velocity.getY(), velocity.getZ()
- }, new double[] {
- sigmaPosition, sigmaPosition, sigmaPosition,
- sigmaVelocity, sigmaVelocity, sigmaVelocity
- }, new double[] {
- baseWeight, baseWeight, baseWeight,
- baseWeight, baseWeight, baseWeight
- }, Arrays.asList(propagatorIndex));
- }
- /** Get the position.
- * @return position
- */
- public Vector3D getPosition() {
- final double[] pv = getObservedValue();
- return new Vector3D(pv[0], pv[1], pv[2]);
- }
- /** Get the velocity.
- * @return velocity
- */
- public Vector3D getVelocity() {
- final double[] pv = getObservedValue();
- return new Vector3D(pv[3], pv[4], pv[5]);
- }
- /** {@inheritDoc} */
- @Override
- protected EstimatedMeasurement<PV> theoreticalEvaluation(final int iteration, final int evaluation,
- final SpacecraftState[] states)
- throws OrekitException {
- // PV value
- final TimeStampedPVCoordinates pv = states[getPropagatorsIndices().get(0)].getPVCoordinates();
- // prepare the evaluation
- final EstimatedMeasurement<PV> estimated =
- new EstimatedMeasurement<>(this, iteration, evaluation, states,
- new TimeStampedPVCoordinates[] {
- pv
- });
- estimated.setEstimatedValue(new double[] {
- pv.getPosition().getX(), pv.getPosition().getY(), pv.getPosition().getZ(),
- pv.getVelocity().getX(), pv.getVelocity().getY(), pv.getVelocity().getZ()
- });
- // partial derivatives with respect to state
- estimated.setStateDerivatives(0, IDENTITY);
- return estimated;
- }
- }