1   /* Copyright 2002-2025 CS GROUP
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3    * contributor license agreements.  See the NOTICE file distributed with
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5    * CS licenses this file to You under the Apache License, Version 2.0
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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
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17  package org.orekit.models.earth.ionosphere;
18  
19  import org.hipparchus.CalculusFieldElement;
20  
21  /**
22   * Interface for mapping functions used in the ionospheric delay computation.
23   * <p>
24   * The purpose of an ionospheric mapping function is to convert the
25   * Vertical Total Electron Content (VTEC) to a Slant Total Electron Content (STEC)
26   * using the following formula:
27   * </p> <pre>
28   * STEC = VTEC * m(e)
29   * </pre> <p>
30   * With m(e) the ionospheric mapping function and e the satellite elevation.
31   * </p>
32   * @author Bryan Cazabonne
33   * @since 10.2
34   */
35  public interface IonosphericMappingFunction {
36  
37      /**
38       * This method allows the computation of the ionospheric mapping factor.
39       * @param elevation the elevation of the satellite, in radians.
40       * @return the ionospheric mapping factor.
41       */
42      double mappingFactor(double elevation);
43  
44      /**
45       * This method allows the computation of the ionospheric mapping factor.
46       * @param elevation the elevation of the satellite, in radians.
47       * @param <T> type of the elements
48       * @return the ionospheric mapping factor.
49       */
50      <T extends CalculusFieldElement<T>> T mappingFactor(T elevation);
51  
52  }