Propagator.java

  1. /* Copyright 2002-2020 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;

  19. import java.util.Collection;
  20. import java.util.List;

  22. import org.hipparchus.geometry.euclidean.threed.Rotation;
  23. import org.orekit.annotation.DefaultDataContext;
  24. import org.orekit.attitudes.AttitudeProvider;
  25. import org.orekit.attitudes.InertialProvider;
  26. import org.orekit.data.DataContext;
  27. import org.orekit.frames.Frame;
  28. import org.orekit.frames.Frames;
  29. import org.orekit.propagation.events.EventDetector;
  30. import org.orekit.propagation.sampling.OrekitFixedStepHandler;
  31. import org.orekit.propagation.sampling.OrekitStepHandler;
  32. import org.orekit.time.AbsoluteDate;
  33. import org.orekit.utils.PVCoordinatesProvider;

  35. /** This interface provides a way to propagate an orbit at any time.
  36.  *
  37.  * <p>This interface is the top-level abstraction for orbit propagation.
  38.  * It only allows propagation to a predefined date.
  39.  * It is implemented by analytical models which have no time limit,
  40.  * by orbit readers based on external data files, by numerical integrators
  41.  * using rich force models and by continuous models built after numerical
  42.  * integration has been completed and dense output data as been
  43.  * gathered.</p>
  44.  * <p>Note that one single propagator cannot be called from multiple threads.
  45.  * Its configuration can be changed as there is at least a {@link
  46.  * #resetInitialState(SpacecraftState)} method, and even propagators that do
  47.  * not support resetting state (like the {@link
  48.  * org.orekit.propagation.analytical.tle.TLEPropagator TLEPropagator} do
  49.  * cache some internal data during computation. However, as long as they
  50.  * are configured with independent building blocks (mainly event handlers
  51.  * and step handlers that may preserve some internal state), and as long
  52.  * as they are called from one thread only, they <em>can</em> be used in
  53.  * multi-threaded applications. Synchronizing several propagators to run in
  54.  * parallel is also possible using {@link PropagatorsParallelizer}.</p>
  55.  * @author Luc Maisonobe
  56.  * @author V&eacute;ronique Pommier-Maurussane
  57.  *
  58.  */

  60. public interface Propagator extends PVCoordinatesProvider {

  62.     /** Default mass. */
  63.     double DEFAULT_MASS = 1000.0;

  65.     /** Default attitude provider.
  66.      *
  67.      * <p>This field uses the {@link DataContext#getDefault() default data context}.
  68.      *
  69.      * @see InertialProvider#InertialProvider(Rotation, Frame)
  70.      * @see #getDefaultLaw(Frames)
  71.      */
  72.     @DefaultDataContext
  73.     AttitudeProvider DEFAULT_LAW = InertialProvider.EME2000_ALIGNED;

  75.     /** Indicator for slave mode. */
  76.     int SLAVE_MODE = 0;

  78.     /** Indicator for master mode. */
  79.     int MASTER_MODE = 1;

  81.     /** Indicator for ephemeris generation mode. */
  82.     int EPHEMERIS_GENERATION_MODE = 2;

  84.     /**
  85.      * Get a default law using the given frames. A data context aware replacement for
  86.      * {@link #DEFAULT_LAW}.
  87.      *
  88.      * @param frames the set of frames to use.
  89.      * @return attitude law.
  90.      */
  91.     static AttitudeProvider getDefaultLaw(final Frames frames) {
  92.         return new InertialProvider(Rotation.IDENTITY, frames.getEME2000());
  93.     }

  95.     /** Get the current operating mode of the propagator.
  96.      * @return one of {@link #SLAVE_MODE}, {@link #MASTER_MODE},
  97.      * {@link #EPHEMERIS_GENERATION_MODE}
  98.      * @see #setSlaveMode()
  99.      * @see #setMasterMode(double, OrekitFixedStepHandler)
  100.      * @see #setMasterMode(OrekitStepHandler)
  101.      * @see #setEphemerisMode()
  102.      */
  103.     int getMode();

  105.     /** Set the propagator to slave mode.
  106.      * <p>This mode is used when the user needs only the final orbit at the target time.
  107.      *  The (slave) propagator computes this result and return it to the calling
  108.      *  (master) application, without any intermediate feedback.
  109.      * <p>This is the default mode.</p>
  110.      * @see #setMasterMode(double, OrekitFixedStepHandler)
  111.      * @see #setMasterMode(OrekitStepHandler)
  112.      * @see #setEphemerisMode()
  113.      * @see #getMode()
  114.      * @see #SLAVE_MODE
  115.      */
  116.     void setSlaveMode();

  118.     /** Set the propagator to master mode with fixed steps.
  119.      * <p>This mode is used when the user needs to have some custom function called at the
  120.      * end of each finalized step during integration. The (master) propagator integration
  121.      * loop calls the (slave) application callback methods at each finalized step.</p>
  122.      * @param h fixed stepsize (s)
  123.      * @param handler handler called at the end of each finalized step
  124.      * @see #setSlaveMode()
  125.      * @see #setMasterMode(OrekitStepHandler)
  126.      * @see #setEphemerisMode()
  127.      * @see #getMode()
  128.      * @see #MASTER_MODE
  129.      */
  130.     void setMasterMode(double h, OrekitFixedStepHandler handler);

  132.     /** Set the propagator to master mode with variable steps.
  133.      * <p>This mode is used when the user needs to have some custom function called at the
  134.      * end of each finalized step during integration. The (master) propagator integration
  135.      * loop calls the (slave) application callback methods at each finalized step.</p>
  136.      * @param handler handler called at the end of each finalized step
  137.      * @see #setSlaveMode()
  138.      * @see #setMasterMode(double, OrekitFixedStepHandler)
  139.      * @see #setEphemerisMode()
  140.      * @see #getMode()
  141.      * @see #MASTER_MODE
  142.      */
  143.     void setMasterMode(OrekitStepHandler handler);

  145.     /** Set the propagator to ephemeris generation mode.
  146.      *  <p>This mode is used when the user needs random access to the orbit state at any time
  147.      *  between the initial and target times, and in no sequential order. A typical example is
  148.      *  the implementation of search and iterative algorithms that may navigate forward and
  149.      *  backward inside the propagation range before finding their result.</p>
  150.      *  <p>Beware that since this mode stores <strong>all</strong> intermediate results,
  151.      *  it may be memory intensive for long integration ranges and high precision/short
  152.      *  time steps.</p>
  153.      * @see #getGeneratedEphemeris()
  154.      * @see #setSlaveMode()
  155.      * @see #setMasterMode(double, OrekitFixedStepHandler)
  156.      * @see #setMasterMode(OrekitStepHandler)
  157.      * @see #getMode()
  158.      * @see #EPHEMERIS_GENERATION_MODE
  159.      */
  160.     void setEphemerisMode();

  162.     /**
  163.      * Set the propagator to ephemeris generation mode with the specified handler for each
  164.      * integration step.
  165.      *
  166.      * <p>This mode is used when the user needs random access to the orbit state at any
  167.      * time between the initial and target times, as well as access to the steps computed
  168.      * by the integrator as in Master Mode. A typical example is the implementation of
  169.      * search and iterative algorithms that may navigate forward and backward inside the
  170.      * propagation range before finding their result.</p>
  171.      *
  172.      * <p>Beware that since this mode stores <strong>all</strong> intermediate results, it
  173.      * may be memory intensive for long integration ranges and high precision/short time
  174.      * steps.</p>
  175.      *
  176.      * @param handler handler called at the end of each finalized step
  177.      * @see #setEphemerisMode()
  178.      * @see #getGeneratedEphemeris()
  179.      * @see #setSlaveMode()
  180.      * @see #setMasterMode(double, OrekitFixedStepHandler)
  181.      * @see #setMasterMode(OrekitStepHandler)
  182.      * @see #getMode()
  183.      * @see #EPHEMERIS_GENERATION_MODE
  184.      */
  185.     void setEphemerisMode(OrekitStepHandler handler);

  187.     /** Get the ephemeris generated during propagation.
  188.      * @return generated ephemeris
  189.      * @exception IllegalStateException if the propagator was not set in ephemeris
  190.      * generation mode before propagation
  191.      * @see #setEphemerisMode()
  192.      */
  193.     BoundedPropagator getGeneratedEphemeris() throws IllegalStateException;

  195.     /** Get the propagator initial state.
  196.      * @return initial state
  197.      */
  198.     SpacecraftState getInitialState();

  200.     /** Reset the propagator initial state.
  201.      * @param state new initial state to consider
  202.      */
  203.     void resetInitialState(SpacecraftState state);

  205.     /** Add a set of user-specified state parameters to be computed along with the orbit propagation.
  206.      * @param additionalStateProvider provider for additional state
  207.      */
  208.     void addAdditionalStateProvider(AdditionalStateProvider additionalStateProvider);

  210.     /** Get an unmodifiable list of providers for additional state.
  211.      * @return providers for the additional states
  212.      */
  213.     List<AdditionalStateProvider> getAdditionalStateProviders();

  215.     /** Check if an additional state is managed.
  216.      * <p>
  217.      * Managed states are states for which the propagators know how to compute
  218.      * its evolution. They correspond to additional states for which an
  219.      * {@link AdditionalStateProvider additional state provider} has been registered
  220.      * by calling the {@link #addAdditionalStateProvider(AdditionalStateProvider)
  221.      * addAdditionalStateProvider} method. If the propagator is an {@link
  222.      * org.orekit.propagation.integration.AbstractIntegratedPropagator integrator-based
  223.      * propagator}, the states for which a set of {@link
  224.      * org.orekit.propagation.integration.AdditionalEquations additional equations} has
  225.      * been registered by calling the {@link
  226.      * org.orekit.propagation.integration.AbstractIntegratedPropagator#addAdditionalEquations(
  227.      * org.orekit.propagation.integration.AdditionalEquations) addAdditionalEquations}
  228.      * method are also counted as managed additional states.
  229.      * </p>
  230.      * <p>
  231.      * Additional states that are present in the {@link #getInitialState() initial state}
  232.      * but have no evolution method registered are <em>not</em> considered as managed states.
  233.      * These unmanaged additional states are not lost during propagation, though. Their
  234.      * value are piecewise constant between state resets that may change them if some
  235.      * event handler {@link
  236.      * org.orekit.propagation.events.handlers.EventHandler#resetState(EventDetector,
  237.      * SpacecraftState) resetState} method is called at an event occurrence and happens
  238.      * to change the unmanaged additional state.
  239.      * </p>
  240.      * @param name name of the additional state
  241.      * @return true if the additional state is managed
  242.      */
  243.     boolean isAdditionalStateManaged(String name);

  245.     /** Get all the names of all managed states.
  246.      * @return names of all managed states
  247.      */
  248.     String[] getManagedAdditionalStates();

  250.     /** Add an event detector.
  251.      * @param detector event detector to add
  252.      * @see #clearEventsDetectors()
  253.      * @see #getEventsDetectors()
  254.      * @param <T> class type for the generic version
  255.      */
  256.     <T extends EventDetector> void addEventDetector(T detector);

  258.     /** Get all the events detectors that have been added.
  259.      * @return an unmodifiable collection of the added detectors
  260.      * @see #addEventDetector(EventDetector)
  261.      * @see #clearEventsDetectors()
  262.      */
  263.     Collection<EventDetector> getEventsDetectors();

  265.     /** Remove all events detectors.
  266.      * @see #addEventDetector(EventDetector)
  267.      * @see #getEventsDetectors()
  268.      */
  269.     void clearEventsDetectors();

  271.     /** Get attitude provider.
  272.      * @return attitude provider
  273.      */
  274.     AttitudeProvider getAttitudeProvider();

  276.     /** Set attitude provider.
  277.      * @param attitudeProvider attitude provider
  278.      */
  279.     void setAttitudeProvider(AttitudeProvider attitudeProvider);

  281.     /** Get the frame in which the orbit is propagated.
  282.      * <p>
  283.      * The propagation frame is the definition frame of the initial
  284.      * state, so this method should be called after this state has
  285.      * been set, otherwise it may return null.
  286.      * </p>
  287.      * @return frame in which the orbit is propagated
  288.      * @see #resetInitialState(SpacecraftState)
  289.      */
  290.     Frame getFrame();

  292.     /** Propagate towards a target date.
  293.      * <p>Simple propagators use only the target date as the specification for
  294.      * computing the propagated state. More feature rich propagators can consider
  295.      * other information and provide different operating modes or G-stop
  296.      * facilities to stop at pinpointed events occurrences. In these cases, the
  297.      * target date is only a hint, not a mandatory objective.</p>
  298.      * @param target target date towards which orbit state should be propagated
  299.      * @return propagated state
  300.      */
  301.     SpacecraftState propagate(AbsoluteDate target);

  303.     /** Propagate from a start date towards a target date.
  304.      * <p>Those propagators use a start date and a target date to
  305.      * compute the propagated state. For propagators using event detection mechanism,
  306.      * if the provided start date is different from the initial state date, a first,
  307.      * simple propagation is performed, without processing any event computation.
  308.      * Then complete propagation is performed from start date to target date.</p>
  309.      * @param start start date from which orbit state should be propagated
  310.      * @param target target date to which orbit state should be propagated
  311.      * @return propagated state
  312.      */
  313.     SpacecraftState propagate(AbsoluteDate start, AbsoluteDate target);

  315. }
Created with JaCoCo 0.8.6.202009150832