AngularRaDecBuilder.java

/* Copyright 2002-2026 CS GROUP
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 * 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
 *
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package org.orekit.estimation.measurements.generation;

import java.util.Map;

import org.orekit.estimation.measurements.AngularRaDec;
import org.orekit.estimation.measurements.GroundStation;
import org.orekit.estimation.measurements.MeasurementQuality;
import org.orekit.estimation.measurements.ObservableSatellite;
import org.orekit.estimation.measurements.Observer;
import org.orekit.frames.Frame;
import org.orekit.propagation.sampling.OrekitStepInterpolator;
import org.orekit.signal.SignalTravelTimeModel;
import org.orekit.time.AbsoluteDate;

/** Builder for {@link AngularRaDec} measurements.
 * @author Luc Maisonobe
 * @since 9.3
 */
public class AngularRaDecBuilder extends AbstractSignalBasedBuilder<AngularRaDec> {

    /** Sensor. */
    private final Observer observer;

    /** Reference frame in which the right ascension - declination angles are given. */
    private final Frame referenceFrame;

    /** Simple constructor.
     * @param station ground station from which measurement is performed
     * @param referenceFrame Reference frame in which the right ascension - declination angles are given
     * @param sigma theoretical standard deviation
     * @param baseWeight base weight
     * @param satellite satellite related to this builder
     */
    public AngularRaDecBuilder(final GroundStation station,
                               final Frame referenceFrame, final double[] sigma, final double[] baseWeight,
                               final ObservableSatellite satellite) {
        this(station, referenceFrame, new MeasurementQuality(sigma, baseWeight), new SignalTravelTimeModel(), satellite);
    }

    /** Simple constructor.
     * @param observer sensor from which measurement is performed
     * @param referenceFrame Reference frame in which the right ascension - declination angles are given
     * @param measurementQuality measurement quality as used in estimation (in Orekit, the crossed-terms
     *                           of the covariance matrix are only used by Kalman filters, not least squares)
     * @param signalTravelTimeModel signal travel time model
     * @param satellite satellite related to this builder
     * @since 14.0
     */
    public AngularRaDecBuilder(final Observer observer,
                               final Frame referenceFrame, final MeasurementQuality measurementQuality,
                               final SignalTravelTimeModel signalTravelTimeModel, final ObservableSatellite satellite) {
        super(measurementQuality, signalTravelTimeModel, satellite);
        this.observer = observer;
        this.referenceFrame = referenceFrame;
    }

    /**
     * Getter for the observer.
     * @return observer
     * @since 14.0
     */
    public Observer getObserver() {
        return observer;
    }

    /** {@inheritDoc} */
    @Override
    protected AngularRaDec buildObserved(final AbsoluteDate date,
                                         final Map<ObservableSatellite, OrekitStepInterpolator> interpolators) {
        return new AngularRaDec(observer, referenceFrame, date, new double[2], getMeasurementQuality(),
                                getSignalTravelTimeModel(), getSatellites()[0]);
    }

}