1   /* Copyright 2002-2024 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.forces.drag;
18  
19  import java.util.List;
20  
21  import org.hipparchus.CalculusFieldElement;
22  import org.hipparchus.geometry.euclidean.threed.FieldVector3D;
23  import org.hipparchus.geometry.euclidean.threed.Vector3D;
24  import org.orekit.propagation.FieldSpacecraftState;
25  import org.orekit.propagation.SpacecraftState;
26  import org.orekit.utils.ParameterDriver;
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 global multiplicative factor.
37       * @since 12.0
38       */
39      String GLOBAL_DRAG_FACTOR = "global drag factor";
40  
41      /** Parameter name for drag coefficient. */
42      String DRAG_COEFFICIENT = "drag coefficient";
43  
44      /** Parameter name for lift ration enabling Jacobian processing.
45       * <p>
46       * The lift ratio is the proportion of atmosphere modecules that will
47       * experience specular reflection when hitting spacecraft instead
48       * of experiencing diffuse reflection. The ratio is between 0 and 1,
49       * 0 meaning there are no specular reflection, only diffuse reflection,
50       * and hence no lift effect.
51       * </p>
52       * @since 9.0
53       */
54      String LIFT_RATIO = "lift ratio";
55  
56      /** Check if model depends on attitude's rotation rate or acceleration at a given, fixed date.
57       * If false, it essentially means that at most the attitude's rotation is used when computing the acceleration vector.
58       * The default implementation returns false as common models for orbital mechanics do not.
59       * @return true if force model depends on attitude derivatives
60       * @since 12.1
61       */
62      default boolean dependsOnAttitudeRate() {
63          return false;
64      }
65  
66      /** Get the drivers for supported parameters.
67       * @return parameters drivers
68       * @since 8.0
69       */
70      List<ParameterDriver> getDragParametersDrivers();
71  
72      /** Compute the acceleration due to drag.
73       * <p>
74       * The computation includes all spacecraft specific characteristics
75       * like shape, area and coefficients.
76       * </p>
77       * @param state current state
78       * @param density atmospheric density at spacecraft position
79       * @param relativeVelocity relative velocity of atmosphere with respect to spacecraft,
80       * in the same inertial frame as spacecraft orbit (m/s)
81       * @param parameters values of the force model parameters
82       * @return spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)
83       * @since 12.0
84       */
85      Vector3D dragAcceleration(SpacecraftState state,
86                                double density, Vector3D relativeVelocity,
87                                double[] parameters);
88  
89      /** Compute the acceleration due to drag.
90       * <p>
91       * The computation includes all spacecraft specific characteristics
92       * like shape, area and coefficients.
93       * </p>
94       * @param state current state
95       * @param density atmospheric density at spacecraft position
96       * @param relativeVelocity relative velocity of atmosphere with respect to spacecraft,
97       * in the same inertial frame as spacecraft orbit (m/s)
98       * @param parameters values of the force model parameters
99       * @param <T> instance of a CalculusFieldElement
100      * @return spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)
101      * @since 12.0
102      */
103     <T extends CalculusFieldElement<T>> FieldVector3D<T> dragAcceleration(FieldSpacecraftState<T> state,
104                                                                           T density, FieldVector3D<T> relativeVelocity,
105                                                                           T[] parameters);
106 }