1   /* Copyright 2022-2025 Thales Alenia Space
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    * 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.troposphere;
18  
19  import org.hipparchus.CalculusFieldElement;
20  import org.orekit.bodies.FieldGeodeticPoint;
21  import org.orekit.bodies.GeodeticPoint;
22  import org.orekit.time.AbsoluteDate;
23  import org.orekit.time.FieldAbsoluteDate;
24  
25  /** Provider for {@link ViennaOne} and {@link ViennaThree} coefficients a<sub>h</sub> and a<sub>w</sub>.
26   * @since 12.1
27   * @author Luc Maisonobe
28   */
29  public interface ViennaAProvider {
30  
31      /** Get coefficients array for VMF mapping function.
32       * <ul>
33       * <li>double[0] = a<sub>h</sub>
34       * <li>double[1] = a<sub>w</sub>
35       * </ul>
36       * @param location location at which parameters are requested
37       * @param date date at which parameters are requested
38       * @return the coefficients array for VMF mapping function
39       */
40      ViennaACoefficients getA(GeodeticPoint location, AbsoluteDate date);
41  
42      /** Get coefficients array for VMF mapping function.
43       * <ul>
44       * <li>double[0] = a<sub>h</sub>
45       * <li>double[1] = a<sub>w</sub>
46       * </ul>
47       * @param <T> type of the field elements
48       * @param location location at which parameters are requested
49       * @param date date at which parameters are requested
50       * @return the coefficients array for VMF mapping function
51       */
52      <T extends CalculusFieldElement<T>> FieldViennaACoefficients<T> getA(FieldGeodeticPoint<T> location,
53                                                                           FieldAbsoluteDate<T> date);
54  
55  }