1   /* Copyright 2022-2025 Thales Alenia Space
2    * Licensed to CS Communication & Systèmes (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 constant Vienna A coefficients.
26   * @author Luc Maisonobe
27   * @since 12.1
28   */
29  public class ConstantViennaAProvider implements ViennaAProvider {
30  
31      /** Constant parameters. */
32      private final ViennaACoefficients a;
33  
34      /** Simple constructor.
35       * @param a constant parameters
36       */
37      public ConstantViennaAProvider(final ViennaACoefficients a) {
38          this.a = a;
39      }
40  
41      /** {@inheritDoc} */
42      @Override
43      public ViennaACoefficients getA(final GeodeticPoint location, final AbsoluteDate date) {
44          return a;
45      }
46  
47      /** {@inheritDoc} */
48      @Override
49      public <T extends CalculusFieldElement<T>> FieldViennaACoefficients<T> getA(final FieldGeodeticPoint<T> location,
50                                                                                  final FieldAbsoluteDate<T> date) {
51          return new FieldViennaACoefficients<>(date.getField().getZero().newInstance(a.getAh()),
52                  date.getField().getZero().newInstance(a.getAw()));
53      }
54  
55  }