BistaticRangeTroposphericDelayModifier.java

  1. /* Copyright 2002-2024 Mark Rutten
  2.  * Licensed to CS GROUP (CS) under one or more
  3.  * contributor license agreements.  See the NOTICE file distributed with
  4.  * this work for additional information regarding copyright ownership.
  5.  * Mark Rutten licenses this file to You under the Apache License, Version 2.0
  6.  * (the "License"); you may not use this file except in compliance with
  7.  * the License.  You may obtain a copy of the License at
  8.  *
  9.  *   http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  17. package org.orekit.estimation.measurements.modifiers;

  18. import org.orekit.attitudes.FrameAlignedProvider;
  19. import org.orekit.estimation.measurements.BistaticRange;
  20. import org.orekit.estimation.measurements.EstimatedMeasurement;
  21. import org.orekit.estimation.measurements.EstimatedMeasurementBase;
  22. import org.orekit.estimation.measurements.EstimationModifier;
  23. import org.orekit.estimation.measurements.GroundStation;
  24. import org.orekit.models.earth.troposphere.DiscreteTroposphericModel;
  25. import org.orekit.propagation.SpacecraftState;

  26. /** Class modifying theoretical bistatic range measurement with tropospheric delay.
  27.  * The effect of tropospheric correction on the range is directly computed
  28.  * through the computation of the tropospheric delay.
  29.  *
  30.  * In general, for GNSS, VLBI, ... there is hardly any frequency dependence in the delay.
  31.  * For SLR techniques however, the frequency dependence is sensitive.
  32.  *
  33.  * @author Maxime Journot
  34.  * @author Joris Olympio
  35.  * @author Mark Rutten
  36.  * @since 11.2
  37.  */
  38. public class BistaticRangeTroposphericDelayModifier extends BaseRangeTroposphericDelayModifier implements EstimationModifier<BistaticRange> {

  39.     /** Constructor.
  40.      *
  41.      * @param model Tropospheric delay model appropriate for the current range measurement method.
  42.      */
  43.     public BistaticRangeTroposphericDelayModifier(final DiscreteTroposphericModel model) {
  44.         super(model);
  45.     }

  46.     /** {@inheritDoc} */
  47.     @Override
  48.     public void modifyWithoutDerivatives(final EstimatedMeasurementBase<BistaticRange> estimated) {
  49.         final BistaticRange measurement = estimated.getObservedMeasurement();
  50.         final GroundStation emitter     = measurement.getEmitterStation();
  51.         final GroundStation receiver    = measurement.getReceiverStation();

  52.         BistaticModifierUtil.modify(estimated, emitter, receiver, this::rangeErrorTroposphericModel);

  53.     }

  54.     /** {@inheritDoc} */
  55.     @Override
  56.     public void modify(final EstimatedMeasurement<BistaticRange> estimated) {
  57.         final BistaticRange measurement = estimated.getObservedMeasurement();
  58.         final GroundStation emitter     = measurement.getEmitterStation();
  59.         final GroundStation receiver    = measurement.getReceiverStation();
  60.         final SpacecraftState state     = estimated.getStates()[0];

  61.         BistaticModifierUtil.modify(estimated, getTropoModel(),
  62.                                     new ModifierGradientConverter(state, 6, new FrameAlignedProvider(state.getFrame())),
  63.                                     emitter, receiver,
  64.                                     this::rangeErrorTroposphericModel,
  65.                                     this::rangeErrorTroposphericModel);

  66.     }

  67. }