1   /* Copyright 2002-2019 CS Systèmes d'Information
2    * Licensed to CS Systèmes d'Information (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    * CS 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.models.earth;
18  
19  import java.io.Serializable;
20  import java.util.List;
21  
22  import org.hipparchus.Field;
23  import org.hipparchus.RealFieldElement;
24  import org.hipparchus.util.MathArrays;
25  import org.orekit.time.AbsoluteDate;
26  import org.orekit.time.FieldAbsoluteDate;
27  import org.orekit.utils.ParameterDriver;
28  
29  /** Interface for mapping functions used in the tropospheric delay computation.
30   * @author Bryan Cazabonne
31   */
32  public interface MappingFunction extends Serializable {
33  
34      /** This method allows the computation of the hydrostatic and
35       * wet mapping functions. The resulting element is an array having the following form:
36       * <ul>
37       * <li>double[0] = m<sub>h</sub>(e) → hydrostatic mapping function
38       * <li>double[1] = m<sub>w</sub>(e) → wet mapping function
39       * </ul>
40       * @param elevation the elevation of the satellite, in radians.
41       * @param height the height of the station in m above sea level.
42       * @param parameters tropospheric model parameters.
43       * @param date current date
44       * @return a two components array containing the hydrostatic and wet mapping functions.
45       */
46      double[] mappingFactors(double elevation, double height, double[] parameters, AbsoluteDate date);
47  
48      /** This method allows the computation of the hydrostatic and
49       * wet mapping functions. The resulting element is an array having the following form:
50       * <ul>
51       * <li>T[0] = m<sub>h</sub>(e) → hydrostatic mapping function
52       * <li>T[1] = m<sub>w</sub>(e) → wet mapping function
53       * </ul>
54       * @param elevation the elevation of the satellite, in radians.
55       * @param height the height of the station in m above sea level.
56       * @param parameters tropospheric model parameters.
57       * @param date current date
58       * @param <T> type of the elements
59       * @return a two components array containing the hydrostatic and wet mapping functions.
60       */
61      <T extends RealFieldElement<T>> T[] mappingFactors(T elevation, T height, T[] parameters, FieldAbsoluteDate<T> date);
62  
63      /** Get the drivers for tropospheric model parameters.
64       * @return drivers for tropospheric model parameters
65       */
66      List<ParameterDriver> getParametersDrivers();
67  
68      /** Get tropospheric model parameters.
69       * @return tropospheric model parameters
70       */
71      default double[] getParameters() {
72          final List<ParameterDriver> drivers = getParametersDrivers();
73          final double[] parameters = new double[drivers.size()];
74          for (int i = 0; i < drivers.size(); ++i) {
75              parameters[i] = drivers.get(i).getValue();
76          }
77          return parameters;
78      }
79  
80      /** Get tropospheric model parameters.
81       * @param field field to which the elements belong
82       * @param <T> type of the elements
83       * @return tropospheric model parameters
84       */
85      default <T extends RealFieldElement<T>> T[] getParameters(final Field<T> field) {
86          final List<ParameterDriver> drivers = getParametersDrivers();
87          final T[] parameters = MathArrays.buildArray(field, drivers.size());
88          for (int i = 0; i < drivers.size(); ++i) {
89              parameters[i] = field.getZero().add(drivers.get(i).getValue());
90          }
91          return parameters;
92      }
93  }