1   /* Copyright 2002-2026 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  
18  package org.orekit.estimation;
19  
20  import org.orekit.bodies.OneAxisEllipsoid;
21  import org.orekit.estimation.measurements.GroundStation;
22  import org.orekit.estimation.measurements.ObserverSatellite;
23  
24  import java.util.ArrayList;
25  import java.util.List;
26  
27  /**
28   * Utility class for station data providers.
29   */
30  public interface StationDataProvider {
31  
32      List<GroundStation> getStations();
33  
34      default List<ObserverSatellite> getSatellites() {
35          return new ArrayList<>();
36      }
37  
38      OneAxisEllipsoid getEarth();
39  
40  }