agi.foundation.propagators

(agi.foundation.models-2024r2.jar)

Class BallisticPropagator

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.propagators.CartesianOnePointPropagator

agi.foundation.propagators.BallisticPropagator

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class BallisticPropagator
extends CartesianOnePointPropagator

This class calculates a ballistic trajectory (two body gravity only) between two locations on a CentralBody (get / set).

Constructor Summary

Constructors

Modifier	Constructor and Description
	BallisticPropagator() Initializes a default instance.
protected	BallisticPropagator(BallisticPropagator existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
	BallisticPropagator(CentralBody centralBody, double gravitationalParameter, JulianDate initialTime, Cartesian initialPositionInertial) Initializes a new instance.

Method Summary

Modifier and Type	Method and Description
BallisticTrajectoryInformation	calculateTrajectoryInformation() Creates an object that contains many metrics which describe the trajectory defined by this object.
protected boolean	checkForSameDefinition(BallisticPropagator other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(CartesianOnePointPropagator other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
Object	clone(CopyContext context) Clones this object using the specified context.
protected int	computeCurrentDefinitionHashCode() Computes a hash code based on the current properties of this object.
BallisticPropagatorSolutionType	configureForMinimumEccentricity(Cartesian targetPositionFixed) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital eccentricity.
BallisticPropagatorSolutionType	configureForMinimumEccentricity(Cartographic targetPosition) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital eccentricity.
BallisticPropagatorSolutionType	configureForMinimumEnergy(Cartesian targetPositionFixed) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital energy.
BallisticPropagatorSolutionType	configureForMinimumEnergy(Cartographic targetPosition) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital energy.
BallisticPropagatorSolutionType	configureFromApogeeAltitude(Cartesian targetPositionFixed, double apogeeAltitude) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory which, at apogee, reaches the specified altitude.
BallisticPropagatorSolutionType	configureFromApogeeAltitude(Cartographic targetPosition, double apogeeAltitude) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory which, at apogee, reaches the specified altitude.
BallisticPropagatorSolutionType	configureFromDeltaV(Cartesian targetPositionFixed, double deltaV, boolean highArc) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for a trajectory which begins with the specified delta-V in the fixed frame.
BallisticPropagatorSolutionType	configureFromDeltaV(Cartographic targetPosition, double deltaV, boolean highArc) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for a trajectory which begins with the specified velocity in the fixed frame.
BallisticPropagatorSolutionType	configureFromFlightDuration(Cartesian targetPositionFixed, Duration flightDuration) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the specified flight duration.
BallisticPropagatorSolutionType	configureFromFlightDuration(Cartographic targetPosition, Duration flightDuration) Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the specified flight duration.
Cartesian	configureInitialPositionFromCartographic(Cartographic initialPosition) Populates the InitialPosition (get / set) property with the position in the inertial frame which corresponds to the given position in the fixed frame at InitialTime (get / set).
Cartesian	configureInitialPositionFromFixedCartesian(Cartesian initialPositionFixed) Populates the InitialPosition (get / set) property with the position in the inertial frame which corresponds to the given position in the fixed frame at InitialTime (get / set).
PropagatorPoint	createPoint() Creates a Point defining the motion of an object following the calculated trajectory.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
CentralBody	getCentralBody() Gets the central body that the InitialPosition (get / set) and target position are located on.
MotionEvaluator1<Cartesian>	getEvaluator(EvaluatorGroup group) Gets an evaluator that can propagate at individual dates.
JulianDate	getFinalTime() Gets the time at which the object arrives at its target position.
double	getGravitationalParameter() Gets the gravitational parameter of the CentralBody (get / set).
Cartesian	getInitialPosition() Gets the initial point of the ballistic trajectory, in the CentralBody (get / set) inertial frame.
JulianDate	getInitialTime() Gets the time at which the object leaves the InitialPosition (get / set) and begins its ballistic flight.
Cartesian	getInitialVelocity() Gets the initial velocity of the ballistic trajectory, in the CentralBody (get / set) inertial frame.
protected ReferenceFrame	getMotionReferenceFrame() Gets the reference frame in which the motion is defined.
void	setCentralBody(CentralBody value) Sets the central body that the InitialPosition (get / set) and target position are located on.
void	setFinalTime(JulianDate value) Sets the time at which the object arrives at its target position.
void	setGravitationalParameter(double value) Sets the gravitational parameter of the CentralBody (get / set).
void	setInitialPosition(Cartesian value) Sets the initial point of the ballistic trajectory, in the CentralBody (get / set) inertial frame.
void	setInitialTime(JulianDate value) Sets the time at which the object leaves the InitialPosition (get / set) and begins its ballistic flight.
void	setInitialVelocity(Cartesian value) Sets the initial velocity of the ballistic trajectory, in the CentralBody (get / set) inertial frame.

Methods inherited from class agi.foundation.propagators.CartesianOnePointPropagator

checkForSameDefinition, getEvaluator, propagate, propagate

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, freezeAggregatedObjects, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BallisticPropagator

public BallisticPropagator()

Initializes a default instance. CentralBody (get / set) is set to the Earth (get) in the CalculationContext's CentralBodiesFacet, and GravitationalParameter (get / set) is set to EarthGravitationalModel2008.GravitationalParameter. InitialTime (get / set), InitialPosition (get / set), FinalTime (get / set), and InitialVelocity (get / set) must be set prior to calling BallisticPropagator.createPoint() or BallisticPropagator.getEvaluator(agi.foundation.EvaluatorGroup), either directly or through the relevant configuration methods.

BallisticPropagator

public BallisticPropagator(CentralBody centralBody,
                           double gravitationalParameter,
                           @Nonnull
                           JulianDate initialTime,
                           @Nonnull
                           Cartesian initialPositionInertial)

Initializes a new instance. This constructor sets the CentralBody (get / set), GravitationalParameter (get / set), InitialTime (get / set), and InitialPosition (get / set) properties. FinalTime (get / set) and InitialVelocity (get / set) must be set prior to calling BallisticPropagator.createPoint() or BallisticPropagator.getEvaluator(agi.foundation.EvaluatorGroup), either directly or through the relevant configuration methods.

Parameters:

centralBody - The central body that the initial and target points are located on.

gravitationalParameter - The gravitational parameter of the central body.

initialTime - The time at which the object will leave the initial position.

initialPositionInertial - The beginning of the trajectory, in the inertial frame of the central body.

See Also:

BallisticPropagator.configureForMinimumEnergy(Cartographic), BallisticPropagator.configureForMinimumEnergy(Cartesian), BallisticPropagator.configureForMinimumEccentricity(Cartographic), BallisticPropagator.configureForMinimumEccentricity(Cartesian), BallisticPropagator.configureFromFlightDuration(Cartographic,Duration), BallisticPropagator.configureFromFlightDuration(Cartesian,Duration), BallisticPropagator.configureFromApogeeAltitude(Cartographic,double), BallisticPropagator.configureFromApogeeAltitude(Cartesian,double), BallisticPropagator.configureFromDeltaV(Cartographic,double,boolean), BallisticPropagator.configureFromDeltaV(Cartesian,double,boolean)

BallisticPropagator

protected BallisticPropagator(@Nonnull
                              BallisticPropagator existingInstance,
                              @Nonnull
                              CopyContext context)

Initializes a new instance as a copy of an existing instance.

See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor in a derived class.

Parameters:

existingInstance - The existing instance to copy.

context - A CopyContext that controls the depth of the copy.

Throws:

ArgumentNullException - Thrown when existingInstance or context is null.

Method Detail

clone

public Object clone(CopyContext context)

Clones this object using the specified context.

This method should be implemented to call a copy constructor on the class of the object being cloned. The copy constructor should take the CopyContext as a parameter in addition to the existing instance to copy. The copy constructor should first call CopyContext.addObjectMapping(T, T) to identify the newly constructed instance as a copy of the existing instance. It should then copy all fields, using CopyContext.updateReference(T) to copy any reference fields.

A typical implementation of ICloneWithContext:

public static class MyClass implements ICloneWithContext {
    public MyClass(MyClass existingInstance, CopyContext context) {
        context.addObjectMapping(existingInstance, this);
        someReference = context.updateReference(existingInstance.someReference);
    }

    @Override
    public final Object clone(CopyContext context) {
        return new MyClass(this, context);
    }

    private Object someReference;
}

In general, all fields that are reference types should be copied with a call to CopyContext.updateReference(T). There are a couple of exceptions:

1. Fields that are aggregate parts of the object should always be copied. A referenced object is an aggregate if properties or methods on the object being copied can modify the externally-visible value of the referenced object.
2. If the semantics of the referenced object require that it have a single parent, owner, context, etc., and the object being copied is that parent, owner, or context, then the referenced object should always be copied.

If one of these exceptions applies, the CopyContext should be given an opportunity to update the reference before the reference is copied explicitly. Use CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns the original object, indicating that the context does not have a replacement registered, then copy the object manually by invoking a Clone method, a copy constructor, or by manually constructing a new instance and copying the values.

alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
    alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}

If you are implementing an evaluator (a class that implements IEvaluator), the IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the copy context constructor. Code duplication can be avoided by doing the following:

1. For references to other evaluators ONLY, simply assign the reference in the constructor instead of calling CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to non-evaluators.
2. Call IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the same CopyContext passed to the constructor.
3. Implement IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.

public MyClass(MyClass existingInstance, CopyContext context) {
    super(existingInstance, context);
    someReference = context.updateReference(existingInstance.someReference);
    evaluatorReference = existingInstance.evaluatorReference;
    updateEvaluatorReferences(context);
}

@Override
public void updateEvaluatorReferences(CopyContext context) {
    evaluatorReference = context.updateReference(evaluatorReference);
}

@Override
public Object clone(CopyContext context) {
    return new MyClass(this, context);
}

private Object someReference;
private IEvaluator evaluatorReference;

Specified by:

clone in interface ICloneWithContext

Specified by:

clone in class DefinitionalObject

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

checkForSameDefinition

protected final boolean checkForSameDefinition(CartesianOnePointPropagator other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Specified by:

checkForSameDefinition in class CartesianOnePointPropagator

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

checkForSameDefinition

protected boolean checkForSameDefinition(BallisticPropagator other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

computeCurrentDefinitionHashCode

protected int computeCurrentDefinitionHashCode()

Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the BallisticPropagator.checkForSameDefinition(agi.foundation.propagators.CartesianOnePointPropagator) method.

Overrides:

computeCurrentDefinitionHashCode in class CartesianOnePointPropagator

Returns:

The computed hash code.

enumerateDependencies

public void enumerateDependencies(DependencyEnumerator enumerator)

Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon. Derived classes which contain additional dependencies MUST override this method, call the base implementation, and enumerate dependencies introduced by the derived class.

Specified by:

enumerateDependencies in interface IEnumerateDependencies

Overrides:

enumerateDependencies in class DefinitionalObject

Parameters:

enumerator - The enumerator that is informed of the dependencies of this object.

getCentralBody

public final CentralBody getCentralBody()

Gets the central body that the InitialPosition (get / set) and target position are located on. By default this is set to the Earth (get) in the CentralBodiesFacet in the CalculationContext.

setCentralBody

public final void setCentralBody(CentralBody value)

Sets the central body that the InitialPosition (get / set) and target position are located on. By default this is set to the Earth (get) in the CentralBodiesFacet in the CalculationContext.

getGravitationalParameter

public final double getGravitationalParameter()

Gets the gravitational parameter of the CentralBody (get / set). By default this is set to EarthGravitationalModel1996.GravitationalParameter.

setGravitationalParameter

public final void setGravitationalParameter(double value)

Sets the gravitational parameter of the CentralBody (get / set). By default this is set to EarthGravitationalModel1996.GravitationalParameter.

getInitialTime

@Nonnull
public final JulianDate getInitialTime()

Gets the time at which the object leaves the InitialPosition (get / set) and begins its ballistic flight.

setInitialTime

public final void setInitialTime(@Nonnull
                                 JulianDate value)

Sets the time at which the object leaves the InitialPosition (get / set) and begins its ballistic flight.

getFinalTime

@Nonnull
public final JulianDate getFinalTime()

Gets the time at which the object arrives at its target position. Generally this property and InitialVelocity (get / set) are calculated by calling the configuration method that corresponds to your desired constraint.

See Also:

BallisticPropagator.configureForMinimumEnergy(Cartographic), BallisticPropagator.configureForMinimumEnergy(Cartesian), BallisticPropagator.configureForMinimumEccentricity(Cartographic), BallisticPropagator.configureForMinimumEccentricity(Cartesian), BallisticPropagator.configureFromFlightDuration(Cartographic,Duration), BallisticPropagator.configureFromFlightDuration(Cartesian,Duration), BallisticPropagator.configureFromApogeeAltitude(Cartographic,double), BallisticPropagator.configureFromApogeeAltitude(Cartesian,double), BallisticPropagator.configureFromDeltaV(Cartographic,double,boolean), BallisticPropagator.configureFromDeltaV(Cartesian,double,boolean)

setFinalTime

public final void setFinalTime(@Nonnull
                               JulianDate value)

Sets the time at which the object arrives at its target position. Generally this property and InitialVelocity (get / set) are calculated by calling the configuration method that corresponds to your desired constraint.

See Also:

BallisticPropagator.configureForMinimumEnergy(Cartographic), BallisticPropagator.configureForMinimumEnergy(Cartesian), BallisticPropagator.configureForMinimumEccentricity(Cartographic), BallisticPropagator.configureForMinimumEccentricity(Cartesian), BallisticPropagator.configureFromFlightDuration(Cartographic,Duration), BallisticPropagator.configureFromFlightDuration(Cartesian,Duration), BallisticPropagator.configureFromApogeeAltitude(Cartographic,double), BallisticPropagator.configureFromApogeeAltitude(Cartesian,double), BallisticPropagator.configureFromDeltaV(Cartographic,double,boolean), BallisticPropagator.configureFromDeltaV(Cartesian,double,boolean)

getInitialPosition

@Nonnull
public final Cartesian getInitialPosition()

Gets the initial point of the ballistic trajectory, in the CentralBody (get / set) inertial frame. You can use BallisticPropagator.configureInitialPositionFromCartographic(agi.foundation.coordinates.Cartographic) or BallisticPropagator.configureInitialPositionFromFixedCartesian(agi.foundation.coordinates.Cartesian) to easily set this property from fixed coordinates if the InitialTime (get / set) has already been set.

setInitialPosition

public final void setInitialPosition(@Nonnull
                                     Cartesian value)

Sets the initial point of the ballistic trajectory, in the CentralBody (get / set) inertial frame. You can use BallisticPropagator.configureInitialPositionFromCartographic(agi.foundation.coordinates.Cartographic) or BallisticPropagator.configureInitialPositionFromFixedCartesian(agi.foundation.coordinates.Cartesian) to easily set this property from fixed coordinates if the InitialTime (get / set) has already been set.

getInitialVelocity

@Nonnull
public final Cartesian getInitialVelocity()

Gets the initial velocity of the ballistic trajectory, in the CentralBody (get / set) inertial frame. Generally this property and FinalTime (get / set) are calculated by calling the configuration method that corresponds to your desired constraint.

See Also:

BallisticPropagator.configureForMinimumEnergy(Cartographic), BallisticPropagator.configureForMinimumEnergy(Cartesian), BallisticPropagator.configureForMinimumEccentricity(Cartographic), BallisticPropagator.configureForMinimumEccentricity(Cartesian), BallisticPropagator.configureFromFlightDuration(Cartographic,Duration), BallisticPropagator.configureFromFlightDuration(Cartesian,Duration), BallisticPropagator.configureFromApogeeAltitude(Cartographic,double), BallisticPropagator.configureFromApogeeAltitude(Cartesian,double), BallisticPropagator.configureFromDeltaV(Cartographic,double,boolean), BallisticPropagator.configureFromDeltaV(Cartesian,double,boolean)

setInitialVelocity

public final void setInitialVelocity(@Nonnull
                                     Cartesian value)

Sets the initial velocity of the ballistic trajectory, in the CentralBody (get / set) inertial frame. Generally this property and FinalTime (get / set) are calculated by calling the configuration method that corresponds to your desired constraint.

See Also:

BallisticPropagator.configureForMinimumEnergy(Cartographic), BallisticPropagator.configureForMinimumEnergy(Cartesian), BallisticPropagator.configureForMinimumEccentricity(Cartographic), BallisticPropagator.configureForMinimumEccentricity(Cartesian), BallisticPropagator.configureFromFlightDuration(Cartographic,Duration), BallisticPropagator.configureFromFlightDuration(Cartesian,Duration), BallisticPropagator.configureFromApogeeAltitude(Cartographic,double), BallisticPropagator.configureFromApogeeAltitude(Cartesian,double), BallisticPropagator.configureFromDeltaV(Cartographic,double,boolean), BallisticPropagator.configureFromDeltaV(Cartesian,double,boolean)

configureInitialPositionFromCartographic

@Nonnull
public final Cartesian configureInitialPositionFromCartographic(@Nonnull
                                                                          Cartographic initialPosition)

Populates the InitialPosition (get / set) property with the position in the inertial frame which corresponds to the given position in the fixed frame at InitialTime (get / set). The InitialTime (get / set) must be set prior to calling this method.

Parameters:

initialPosition - The initial position, as a Cartographic in the CentralBody (get / set) fixed frame.

Returns:

The initial position, which will also be set to the InitialPosition (get / set) property.

See Also:

BallisticPropagator.configureInitialPositionFromFixedCartesian(agi.foundation.coordinates.Cartesian)

configureInitialPositionFromFixedCartesian

@Nonnull
public final Cartesian configureInitialPositionFromFixedCartesian(@Nonnull
                                                                            Cartesian initialPositionFixed)

Populates the InitialPosition (get / set) property with the position in the inertial frame which corresponds to the given position in the fixed frame at InitialTime (get / set). The InitialTime (get / set) must be set prior to calling this method.

Parameters:

initialPositionFixed - The initial position in the CentralBody (get / set) fixed frame.

Returns:

The initial position, which will also be set to the InitialPosition (get / set) property.

See Also:

BallisticPropagator.configureInitialPositionFromCartographic(agi.foundation.coordinates.Cartographic)

configureForMinimumEnergy

@Nonnull
public final BallisticPropagatorSolutionType configureForMinimumEnergy(@Nonnull
                                                                                 Cartographic targetPosition)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital energy. This will also correspond to the minimum delta-V required. All other properties must be set prior to calling this method, either directly, on construction, or by using BallisticPropagator.configureInitialPositionFromCartographic(agi.foundation.coordinates.Cartographic) or BallisticPropagator.configureInitialPositionFromFixedCartesian(agi.foundation.coordinates.Cartesian)

Parameters:

targetPosition - The target position, as a Cartographic in the CentralBody (get / set) fixed frame.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureForMinimumEnergy

@Nonnull
public final BallisticPropagatorSolutionType configureForMinimumEnergy(@Nonnull
                                                                                 Cartesian targetPositionFixed)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital energy. This will also correspond to the minimum delta-V required. All other properties must be set prior to calling this method, either directly, on construction, or by using BallisticPropagator.configureInitialPositionFromCartographic(agi.foundation.coordinates.Cartographic) or BallisticPropagator.configureInitialPositionFromFixedCartesian(agi.foundation.coordinates.Cartesian)

Parameters:

targetPositionFixed - The target position in the CentralBody (get / set) fixed frame.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureForMinimumEccentricity

@Nonnull
public final BallisticPropagatorSolutionType configureForMinimumEccentricity(@Nonnull
                                                                                       Cartographic targetPosition)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital eccentricity. With an initial and final point on the surface of the central body this will correspond to a trajectory that skims the surface of the body. This trajectory is mainly used to determine the absolute lower bounds for a reasonable flight duration for a specific initial and final point.

Parameters:

targetPosition - The target position, as a Cartographic in the CentralBody (get / set) fixed frame.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureForMinimumEccentricity

@Nonnull
public final BallisticPropagatorSolutionType configureForMinimumEccentricity(@Nonnull
                                                                                       Cartesian targetPositionFixed)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the minimum orbital eccentricity. With an initial and final point on the surface of the central body this will correspond to a trajectory that skims the surface of the body. This trajectory is mainly used to determine the absolute lower bounds for a reasonable flight duration for a specific initial and final point.

Parameters:

targetPositionFixed - The target position in the CentralBody (get / set) fixed frame.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureFromFlightDuration

@Nonnull
public final BallisticPropagatorSolutionType configureFromFlightDuration(@Nonnull
                                                                                   Cartographic targetPosition,
                                                                                   @Nonnull
                                                                                   Duration flightDuration)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the specified flight duration. If this duration is too short for a valid trajectory then the minimum eccentricity solution will be calculated and BallisticPropagatorSolutionType.INSUFFICIENT_FLIGHT_DURATION will be returned.

Parameters:

targetPosition - The target position, as a Cartographic in the CentralBody (get / set) fixed frame.

flightDuration - The desired flight time from the initial to target position.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureFromFlightDuration

@Nonnull
public final BallisticPropagatorSolutionType configureFromFlightDuration(@Nonnull
                                                                                   Cartesian targetPositionFixed,
                                                                                   @Nonnull
                                                                                   Duration flightDuration)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory with the specified flight duration. If this duration is too short for a valid trajectory then the minimum eccentricity solution will be calculated and BallisticPropagatorSolutionType.INSUFFICIENT_FLIGHT_DURATION will be returned.

Parameters:

targetPositionFixed - The target position in the CentralBody (get / set) fixed frame.

flightDuration - The desired flight time from the initial to target position.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureFromApogeeAltitude

@Nonnull
public final BallisticPropagatorSolutionType configureFromApogeeAltitude(@Nonnull
                                                                                   Cartographic targetPosition,
                                                                                   double apogeeAltitude)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory which, at apogee, reaches the specified altitude.

Parameters:

targetPosition - The target position, as a Cartographic in the CentralBody (get / set) fixed frame.

apogeeAltitude - The desired altitude of the trajectory's apogee, in meters.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureFromApogeeAltitude

@Nonnull
public final BallisticPropagatorSolutionType configureFromApogeeAltitude(@Nonnull
                                                                                   Cartesian targetPositionFixed,
                                                                                   double apogeeAltitude)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for the trajectory which, at apogee, reaches the specified altitude.

Parameters:

targetPositionFixed - The target position in the CentralBody (get / set) fixed frame.

apogeeAltitude - The desired altitude of the trajectory's apogee, in meters.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureFromDeltaV

@Nonnull
public final BallisticPropagatorSolutionType configureFromDeltaV(@Nonnull
                                                                           Cartographic targetPosition,
                                                                           double deltaV,
                                                                           boolean highArc)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for a trajectory which begins with the specified velocity in the fixed frame. There will typically be two solutions with the same delta-V, highArc specifies whether to choose the trajectory that attains a higher or lower altitude. If the specified delta-V is too small for a valid trajectory then the minimum energy solution will be calculated BallisticPropagatorSolutionType.INSUFFICIENT_DELTA_V will be returned.

Parameters:

targetPosition - The target position, as a Cartographic in the CentralBody (get / set) fixed frame.

deltaV - The impulsive delta-V to provide at launch, in meters per second.

highArc - If true the higher angle and altitude, longer time trajectory will be chosen. If false the lower angle and altitude, shorter time trajectory will be chosen.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

configureFromDeltaV

@Nonnull
public final BallisticPropagatorSolutionType configureFromDeltaV(@Nonnull
                                                                           Cartesian targetPositionFixed,
                                                                           double deltaV,
                                                                           boolean highArc)

Populates the InitialVelocity (get / set) and FinalTime (get / set) values for a trajectory which begins with the specified delta-V in the fixed frame. There will typically be two solutions with the same delta-V, highArc specifies whether to choose the trajectory that attains a higher or lower altitude. If the specified delta-V is too small for a valid trajectory then the minimum energy solution will be calculated BallisticPropagatorSolutionType.INSUFFICIENT_DELTA_V will be returned.

Parameters:

targetPositionFixed - The target position in the CentralBody (get / set) fixed frame.

deltaV - The impulsive delta-V to provide at launch, in meters per second.

highArc - If true the higher angle and altitude, longer time trajectory will be chosen. If false the lower angle and altitude, shorter time trajectory will be chosen.

Returns:

An enumeration which reports whether the calculation successfully met the provided constraint, or contains an alternative solution or best guess.

calculateTrajectoryInformation

@Nonnull
public final BallisticTrajectoryInformation calculateTrajectoryInformation()

Creates an object that contains many metrics which describe the trajectory defined by this object. This object must be fully configured before this method is called.

Returns:

An object with general information about the trajectory.

createPoint

public PropagatorPoint createPoint()

Creates a Point defining the motion of an object following the calculated trajectory. This object must be fully configured before this method is called.

Overrides:

createPoint in class CartesianOnePointPropagator

Returns:

The created point.

getEvaluator

public MotionEvaluator1<Cartesian> getEvaluator(EvaluatorGroup group)

Gets an evaluator that can propagate at individual dates.

This evaluator propagates the orbit state from the InitialTime (get / set) to the FinalTime (get / set) based on the InitialPosition (get / set), InitialVelocity (get / set), and GravitationalParameter (get / set). The result of evaluating will be a Motion<Cartesian> corresponding to the orbital position and velocity at the given JulianDate expressed in the propagator's ReferenceFrame.

Specified by:

getEvaluator in class CartesianOnePointPropagator

Parameters:

group - The group with which to associate the new evaluator. By grouping evaluators that are often evaluated at the same Julian dates, common computations can be performed only once for the entire group instead of multiple times for each evaluator.

Returns:

The evaluator.

See Also:

CartesianOnePointPropagator.createPoint()

getMotionReferenceFrame

protected ReferenceFrame getMotionReferenceFrame()

Gets the reference frame in which the motion is defined.

Specified by:

getMotionReferenceFrame in class CartesianOnePointPropagator

Returns:

The reference frame.