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9    *   http://www.apache.org/licenses/LICENSE-2.0
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11   * Unless required by applicable law or agreed to in writing, software
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14   * See the License for the specific language governing permissions and
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17  package org.orekit.estimation.measurements.modifiers;
18  
19  import java.util.Collections;
20  import java.util.List;
21  
22  import org.orekit.estimation.measurements.EstimatedMeasurementBase;
23  import org.orekit.estimation.measurements.EstimationModifier;
24  import org.orekit.estimation.measurements.gnss.OneWayGNSSPhase;
25  import org.orekit.utils.Constants;
26  import org.orekit.utils.ParameterDriver;
27  
28  /** Class modifying theoretical one-way GNSS phase measurement with relativistic clock correction.
29   * <p>
30   * Relativistic clock correction is caused by the motion of the satellite as well as
31   * the change in the gravitational potential
32   * </p>
33   * @author Bryan Cazabonne
34   * @since 10.3
35   *
36   * @see "Teunissen, Peter, and Oliver Montenbruck, eds. Springer handbook of global navigation
37   * satellite systems. Chapter 19.2. Springer, 2017."
38   */
39  public class RelativisticClockOneWayGNSSPhaseModifier extends AbstractRelativisticClockModifier implements EstimationModifier<OneWayGNSSPhase> {
40  
41      /** Simple constructor. */
42      public RelativisticClockOneWayGNSSPhaseModifier() {
43          super();
44      }
45  
46      /** {@inheritDoc} */
47      @Override
48      public List<ParameterDriver> getParametersDrivers() {
49          return Collections.emptyList();
50      }
51  
52      /** {@inheritDoc} */
53      @Override
54      public void modifyWithoutDerivatives(final EstimatedMeasurementBase<OneWayGNSSPhase> estimated) {
55          // Relativistic clock correction
56          final double dtRel = relativisticCorrection(estimated);
57  
58          // Wavelength
59          final double wavelength  = estimated.getObservedMeasurement().getWavelength();
60          final double cOverLambda = Constants.SPEED_OF_LIGHT / wavelength;
61  
62          // Update estimated value taking into account the relativistic effect.
63          final double[] newValue = estimated.getEstimatedValue().clone();
64          newValue[0] = newValue[0] - dtRel * cOverLambda;
65          estimated.modifyEstimatedValue(this, newValue);
66      }
67  
68  }