PositionBuilder.java
- /* Copyright 2002-2024 CS GROUP
- * Licensed to CS GROUP (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.generation;
- import java.util.Map;
- import org.hipparchus.geometry.euclidean.threed.Vector3D;
- import org.hipparchus.random.CorrelatedRandomVectorGenerator;
- import org.orekit.estimation.measurements.EstimationModifier;
- import org.orekit.estimation.measurements.ObservableSatellite;
- import org.orekit.estimation.measurements.Position;
- import org.orekit.propagation.SpacecraftState;
- import org.orekit.propagation.sampling.OrekitStepInterpolator;
- import org.orekit.time.AbsoluteDate;
- import org.orekit.utils.ParameterDriver;
- /** Builder for {@link Position} measurements.
- * @author Luc Maisonobe
- * @since 9.3
- */
- public class PositionBuilder extends AbstractMeasurementBuilder<Position> {
- /** Satellite related to this builder.
- * @since 12.0
- */
- private final ObservableSatellite satellite;
- /** Simple constructor.
- * @param noiseSource noise source, may be null for generating perfect measurements
- * @param sigma theoretical standard deviation
- * @param baseWeight base weight
- * @param satellite satellite related to this builder
- */
- public PositionBuilder(final CorrelatedRandomVectorGenerator noiseSource,
- final double sigma, final double baseWeight,
- final ObservableSatellite satellite) {
- super(noiseSource, sigma, baseWeight, satellite);
- this.satellite = satellite;
- }
- /** {@inheritDoc} */
- @Override
- public Position build(final AbsoluteDate date, final Map<ObservableSatellite, OrekitStepInterpolator> interpolators) {
- final double sigma = getTheoreticalStandardDeviation()[0];
- final double baseWeight = getBaseWeight()[0];
- final SpacecraftState[] relevant = new SpacecraftState[] { interpolators.get(satellite).getInterpolatedState(date) };
- // create a dummy measurement
- final Position dummy = new Position(relevant[0].getDate(), Vector3D.NaN, sigma, baseWeight, satellite);
- for (final EstimationModifier<Position> modifier : getModifiers()) {
- dummy.addModifier(modifier);
- }
- // set a reference date for parameters missing one
- for (final ParameterDriver driver : dummy.getParametersDrivers()) {
- if (driver.getReferenceDate() == null) {
- final AbsoluteDate start = getStart();
- final AbsoluteDate end = getEnd();
- driver.setReferenceDate(start.durationFrom(end) <= 0 ? start : end);
- }
- }
- // estimate the perfect value of the measurement
- final double[] position = dummy.estimateWithoutDerivatives(0, 0, relevant).getEstimatedValue();
- // add the noise
- final double[] noise = getNoise();
- if (noise != null) {
- position[0] += noise[0];
- position[1] += noise[1];
- position[2] += noise[2];
- }
- // generate measurement
- final Position measurement = new Position(relevant[0].getDate(), new Vector3D(position),
- sigma, baseWeight, satellite);
- for (final EstimationModifier<Position> modifier : getModifiers()) {
- measurement.addModifier(modifier);
- }
- return measurement;
- }
- }