1   /* Copyright 2002-2025 CS GROUP
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.propagation.conversion;
18  
19  import java.util.List;
20  
21  import org.orekit.propagation.Propagator;
22  import org.orekit.propagation.SpacecraftState;
23  
24  /** This interface is the top-level abstraction for propagators conversions.
25   * <p>
26   * It provides a way to convert a given propagator or a set of {@link SpacecraftState}
27   * into a wanted propagator that minimize the mean square error over a time span.
28   * </p>
29   * @author Pascal Parraud
30   * @since 6.0
31   */
32  public interface PropagatorConverter {
33  
34      /** Convert a propagator into another one.
35       * @param source propagator to convert
36       * @param timeSpan time span considered for conversion
37       * @param nbPoints number of points for sampling over the time span
38       * @param freeParameters names of the free parameters
39       * @return adapted propagator
40       */
41      Propagator convert(Propagator source,
42                         double timeSpan,
43                         int nbPoints,
44                         List<String> freeParameters);
45  
46      /** Convert a propagator into another one.
47       * @param source propagator to convert
48       * @param timeSpan time span considered for conversion
49       * @param nbPoints number of points for sampling over the time span
50       * @param freeParameters names of the free parameters
51       * @return adapted propagator
52       */
53      Propagator convert(Propagator source,
54                         double timeSpan,
55                         int nbPoints,
56                         String... freeParameters);
57  
58      /** Find the propagator that minimize the mean square error for a sample of {@link SpacecraftState states}.
59       * @param states spacecraft states sample to fit
60       * @param positionOnly if true, consider only position data otherwise both position and velocity are used
61       * @param freeParameters names of the free parameters
62       * @return adapted propagator
63       */
64      Propagator convert(List<SpacecraftState> states,
65                         boolean positionOnly,
66                         List<String> freeParameters);
67  
68      /** Find the propagator that minimize the mean square error for a sample of {@link SpacecraftState states}.
69       * @param states spacecraft states sample to fit
70       * @param positionOnly if true, consider only position data otherwise both position and velocity are used
71       * @param freeParameters names of the free parameters
72       * @return adapted propagator
73       */
74      Propagator convert(List<SpacecraftState> states,
75                         boolean positionOnly,
76                         String... freeParameters);
77  
78  }