1   /* Copyright 2002-2015 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  package org.orekit.forces.drag;
18  
19  import org.apache.commons.math3.analysis.differentiation.DerivativeStructure;
20  import org.apache.commons.math3.geometry.euclidean.threed.FieldRotation;
21  import org.apache.commons.math3.geometry.euclidean.threed.FieldVector3D;
22  import org.apache.commons.math3.geometry.euclidean.threed.Rotation;
23  import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
24  import org.orekit.errors.OrekitException;
25  import org.orekit.frames.Frame;
26  import org.orekit.time.AbsoluteDate;
27  
28  /** Interface for spacecraft that are sensitive to atmospheric drag forces.
29   *
30   * @see DragForce
31   * @author Luc Maisonobe
32   * @author Pascal Parraud
33   */
34  public interface DragSensitive {
35  
36      /** Parameter name for drag coefficient enabling jacobian processing. */
37      String DRAG_COEFFICIENT = "drag coefficient";
38  
39      /** Compute the acceleration due to drag.
40       * <p>
41       * The computation includes all spacecraft specific characteristics
42       * like shape, area and coefficients.
43       * </p>
44       * @param date current date
45       * @param frame inertial reference frame for state (both orbit and attitude)
46       * @param position position of spacecraft in reference frame
47       * @param rotation orientation (attitude) of the spacecraft with respect to reference frame
48       * @param mass current mass
49       * @param density atmospheric density at spacecraft position
50       * @param relativeVelocity relative velocity of atmosphere with respect to spacecraft,
51       * in the same inertial frame as spacecraft orbit (m/s)
52       * @return spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)
53       * @throws OrekitException if acceleration cannot be computed
54       */
55      Vector3D dragAcceleration(AbsoluteDate date, Frame frame, Vector3D position,
56                                Rotation rotation, double mass,
57                                double density, Vector3D relativeVelocity)
58          throws OrekitException;
59  
60      /** Compute the acceleration due to drag, with state derivatives.
61       * <p>
62       * The computation includes all spacecraft specific characteristics
63       * like shape, area and coefficients.
64       * </p>
65       * @param date current date
66       * @param frame inertial reference frame for state (both orbit and attitude)
67       * @param position position of spacecraft in reference frame
68       * @param rotation orientation (attitude) of the spacecraft with respect to reference frame
69       * @param mass spacecraft mass
70       * @param density atmospheric density at spacecraft position
71       * @param relativeVelocity relative velocity of atmosphere with respect to spacecraft,
72       * in the same inertial frame as spacecraft orbit (m/s)
73       * @return spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)
74       * @throws OrekitException if acceleration cannot be computed
75       */
76      FieldVector3D<DerivativeStructure> dragAcceleration(AbsoluteDate date, Frame frame, FieldVector3D<DerivativeStructure> position,
77                                                          FieldRotation<DerivativeStructure> rotation, DerivativeStructure mass,
78                                                          double density, FieldVector3D<DerivativeStructure> relativeVelocity)
79          throws OrekitException;
80  
81      /** Compute acceleration due to drag, with parameters derivatives.
82       * @param date current date
83       * @param frame inertial reference frame for state (both orbit and attitude)
84       * @param position position of spacecraft in reference frame
85       * @param rotation orientation (attitude) of the spacecraft with respect to reference frame
86       * @param mass current mass
87       * @param density atmospheric density at spacecraft position
88       * @param relativeVelocity relative velocity of atmosphere with respect to spacecraft,
89       * in the same inertial frame as spacecraft orbit (m/s)
90       * @param paramName name of the parameter with respect to which derivatives are required
91       * @return spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)
92       * @exception OrekitException if derivatives cannot be computed
93       */
94      FieldVector3D<DerivativeStructure> dragAcceleration(AbsoluteDate date, Frame frame, Vector3D position,
95                                  Rotation rotation, double mass,
96                                  double density, Vector3D relativeVelocity, String paramName)
97          throws OrekitException;
98  
99      /** Set the drag coefficient.
100      *  @param value drag coefficient
101      */
102     void setDragCoefficient(double value);
103 
104     /** Get the drag coefficient.
105      * @return drag coefficient
106      */
107     double getDragCoefficient();
108 
109 }