ForceModel (ORbit Extrapolation KIT 11.3 API)

All Superinterfaces:

ParametersDriversProvider

All Known Implementing Classes:

AbstractDragForceModel, AbstractForceModel, AbstractRadiationForceModel, ConfigurableLowThrustManeuver, ConstantThrustManeuver, CR3BPForceModel, DeSitterRelativity, DragForce, ECOM2, HolmesFeatherstoneAttractionModel, InertialForces, KnockeRediffusedForceModel, LenseThirringRelativity, Maneuver, NewtonianAttraction, OceanTides, ParametricAcceleration, Relativity, SingleBodyAbsoluteAttraction, SingleBodyRelativeAttraction, SolarRadiationPressure, SolidTides, ThirdBodyAttraction, ThirdBodyAttractionEpoch, TimeSpanDragForce, TimeSpanParametricAcceleration
```
public interface ForceModel
extends ParametersDriversProvider
```
This interface represents a force modifying spacecraft motion.
Objects implementing this interface are intended to be added to a numerical propagator before the propagation is started.
The propagator will call at each step the addContribution(SpacecraftState, TimeDerivativesEquations) method. The force model instance will extract all the state data it needs (date, position, velocity, frame, attitude, mass) from the first parameter. From these state data, it will compute the perturbing acceleration. It will then add this acceleration to the second parameter which will take thins contribution into account and will use the Gauss equations to evaluate its impact on the global state derivative.

Force models which create discontinuous acceleration patterns (typically for maneuvers start/stop or solar eclipses entry/exit) must provide one or more events detectors to the propagator thanks to their getEventsDetectors() method. This method is called once just before propagation starts. The events states will be checked by the propagator to ensure accurate propagation and proper events handling.

Author:

Mathieu Roméro, Luc Maisonobe, Véronique Pommier-Maurussane

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`<T extends CalculusFieldElement<T>> FieldVector3D<T>`	`acceleration(FieldSpacecraftState<T> s, T[] parameters)` Compute acceleration.
`Vector3D`	`acceleration(SpacecraftState s, double[] parameters)` Compute acceleration.
`default <T extends CalculusFieldElement<T>> void`	`addContribution(FieldSpacecraftState<T> s, FieldTimeDerivativesEquations<T> adder)` Compute the contribution of the force model to the perturbing acceleration.
`default void`	`addContribution(SpacecraftState s, TimeDerivativesEquations adder)` Compute the contribution of the force model to the perturbing acceleration.
`boolean`	`dependsOnPositionOnly()` Check if force models depends on position only.
`Stream<EventDetector>`	`getEventsDetectors()` Get the discrete events related to the model.
`<T extends CalculusFieldElement<T>> Stream<FieldEventDetector<T>>`	`getFieldEventsDetectors(Field<T> field)` Get the discrete events related to the model.
`ParameterDriver`	`getParameterDriver(String name)` Get parameter value from its name.
`default double[]`	`getParameters()` Get force model parameters.
`default <T extends CalculusFieldElement<T>> T[]`	`getParameters(Field<T> field)` Get force model parameters.
`default <T extends CalculusFieldElement<T>> void`	`init(FieldSpacecraftState<T> initialState, FieldAbsoluteDate<T> target)` Initialize the force model at the start of propagation.
`default void`	`init(SpacecraftState initialState, AbsoluteDate target)` Initialize the force model at the start of propagation.
`boolean`	`isSupported(String name)` Check if a parameter is supported.

Methods inherited from interface org.orekit.utils.ParametersDriversProvider
getParametersDrivers

- Method Detail
  - init
```
default void init(SpacecraftState initialState,
                  AbsoluteDate target)
```
    Initialize the force model at the start of propagation. This method will be called before any calls to addContribution(SpacecraftState, TimeDerivativesEquations), addContribution(FieldSpacecraftState, FieldTimeDerivativesEquations), acceleration(SpacecraftState, double[]) or acceleration(FieldSpacecraftState, CalculusFieldElement[])
    The default implementation of this method does nothing.
    
    Parameters:
    
    initialState - spacecraft state at the start of propagation.
    
    target - date of propagation. Not equal to initialState.getDate().
  - init
```
default <T extends CalculusFieldElement<T>> void init(FieldSpacecraftState<T> initialState,
                                                      FieldAbsoluteDate<T> target)
```
    Initialize the force model at the start of propagation. This method will be called before any calls to addContribution(SpacecraftState, TimeDerivativesEquations), addContribution(FieldSpacecraftState, FieldTimeDerivativesEquations), acceleration(SpacecraftState, double[]) or acceleration(FieldSpacecraftState, CalculusFieldElement[])
    The default implementation of this method does nothing.
    
    Type Parameters:
    
    T - type of the elements
    
    Parameters:
    
    initialState - spacecraft state at the start of propagation.
    
    target - date of propagation. Not equal to initialState.getDate().
  - addContribution
```
default void addContribution(SpacecraftState s,
                             TimeDerivativesEquations adder)
```
    Compute the contribution of the force model to the perturbing acceleration.
    The default implementation simply adds the acceleration as a non-Keplerian acceleration.
    
    Parameters:
    
    s - current state information: date, kinematics, attitude
    
    adder - object where the contribution should be added
  - addContribution
```
default <T extends CalculusFieldElement<T>> void addContribution(FieldSpacecraftState<T> s,
                                                                 FieldTimeDerivativesEquations<T> adder)
```
    Compute the contribution of the force model to the perturbing acceleration.
    
    Type Parameters:
    
    T - type of the elements
    
    Parameters:
    
    s - current state information: date, kinematics, attitude
    
    adder - object where the contribution should be added
  - getParameters
```
default double[] getParameters()
```
    Get force model parameters.
    
    Returns:
    
    force model parameters
    
    Since:
    
    9.0
  - getParameters
```
default <T extends CalculusFieldElement<T>> T[] getParameters(Field<T> field)
```
    Get force model parameters.
    
    Type Parameters:
    
    T - type of the elements
    
    Parameters:
    
    field - field to which the elements belong
    
    Returns:
    
    force model parameters
    
    Since:
    
    9.0
  - dependsOnPositionOnly
```
boolean dependsOnPositionOnly()
```
    Check if force models depends on position only.
    
    Returns:
    
    true if force model depends on position only, false if it depends on velocity, either directly or due to a dependency on attitude
    
    Since:
    
    9.0
  - acceleration
```
Vector3D acceleration(SpacecraftState s,
                      double[] parameters)
```
    Compute acceleration.
    
    Parameters:
    
    s - current state information: date, kinematics, attitude
    
    parameters - values of the force model parameters
    
    Returns:
    
    acceleration in same frame as state
    
    Since:
    
    9.0
  - acceleration
```
<T extends CalculusFieldElement<T>> FieldVector3D<T> acceleration(FieldSpacecraftState<T> s,
                                                                  T[] parameters)
```
    Compute acceleration.
    
    Type Parameters:
    
    T - type of the elements
    
    Parameters:
    
    s - current state information: date, kinematics, attitude
    
    parameters - values of the force model parameters
    
    Returns:
    
    acceleration in same frame as state
    
    Since:
    
    9.0
  - getEventsDetectors
```
Stream<EventDetector> getEventsDetectors()
```
    Get the discrete events related to the model.
    
    Returns:
    
    stream of events detectors
  - getFieldEventsDetectors
```
<T extends CalculusFieldElement<T>> Stream<FieldEventDetector<T>> getFieldEventsDetectors(Field<T> field)
```
    Get the discrete events related to the model.
    
    Type Parameters:
    
    T - extends CalculusFieldElement<T>
    
    Parameters:
    
    field - field to which the state belongs
    
    Returns:
    
    stream of events detectors
  - getParameterDriver
```
ParameterDriver getParameterDriver(String name)
```
    Get parameter value from its name.
    
    Parameters:
    
    name - parameter name
    
    Returns:
    
    parameter value
    
    Since:
    
    8.0
  - isSupported
```
boolean isSupported(String name)
```
    Check if a parameter is supported.
    Supported parameters are those listed by ParametersDriversProvider.getParametersDrivers().
    
    Parameters:
    
    name - parameter name to check
    
    Returns:
    
    true if the parameter is supported
    
    See Also:
    
    ParametersDriversProvider.getParametersDrivers()

Interface ForceModel

Method Summary

Methods inherited from interface org.orekit.utils.ParametersDriversProvider

Method Detail

init

init

addContribution

addContribution

getParameters

getParameters

dependsOnPositionOnly

acceleration

acceleration

getEventsDetectors

getFieldEventsDetectors

getParameterDriver

isSupported