1   /* Copyright 2002-2013 CS Systèmes d'Information
2    * Licensed to CS Systèmes d'Information (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.utils;
19  
20  import org.orekit.errors.OrekitException;
21  import org.orekit.frames.Frame;
22  import org.orekit.time.AbsoluteDate;
23  
24  /**
25  ** Interface for PV coordinates providers.
26   * @author Veronique Pommier
27   * <p>The PV coordinates provider interface can be used by any class used for position/velocity
28   * computation, for example celestial bodies or spacecraft position/velocity propagators,
29   * and many others...
30   * </p>
31   */
32  public interface PVCoordinatesProvider {
33  
34      /** Get the {@link PVCoordinates} of the body in the selected frame.
35       * @param date current date
36       * @param frame the frame where to define the position
37       * @return position/velocity of the body (m and m/s)
38       * @exception OrekitException if position cannot be computed in given frame
39       */
40      PVCoordinates getPVCoordinates(AbsoluteDate date,
41                                     Frame frame) throws OrekitException;
42  
43  }