agi.foundation.geometry

(agi.foundation.core-2025r1.jar)

Class VectorApparentDisplacement

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.geometry.Vector

agi.foundation.geometry.VectorDisplacement

agi.foundation.geometry.VectorApparentDisplacement

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IServiceProvider

public class VectorApparentDisplacement
extends VectorDisplacement

A vector representing the apparent directed displacement from an initial point to a final point as the points move over time. The apparent displacement accounts for light travel time given the SignalDirection and optionally can account for aberration caused by the motion of the observer's frame.

Field Summary

Fields

Modifier and Type	Field and Description
static double	DefaultLightTimeConvergenceTolerance The default tolerance required to indicate convergence of the light travel time adjustment.

Constructor Summary

Constructors

Modifier	Constructor and Description
	VectorApparentDisplacement() Initializes a new instance.
	VectorApparentDisplacement(Point initialPoint, Point finalPoint, ReferenceFrame inertialFrame) Initializes a new instance of the VectorApparentDisplacement class which only accounts for light travel time.
	VectorApparentDisplacement(Point initialPoint, Point finalPoint, ReferenceFrame inertialFrame, SignalDirection direction, double lightTravelTimeConvergenceTolerance) Initializes a new instance of the VectorApparentDisplacement class which only accounts for light travel time.
	VectorApparentDisplacement(Point initialPoint, Point finalPoint, ReferenceFrame inertialFrame, SignalDirection direction, double lightTravelTimeConvergenceTolerance, VectorVelocity velocityOfMovingFrame) Initializes a new instance of the VectorApparentDisplacement class which accounts for aberration in addition to light travel time.
	VectorApparentDisplacement(Point initialPoint, Point finalPoint, ReferenceFrame inertialFrame, VectorVelocity velocityOfMovingFrame) Initializes a new instance of the VectorApparentDisplacement class which accounts for aberration in addition to light travel time.
protected	VectorApparentDisplacement(VectorApparentDisplacement existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(VectorApparentDisplacement other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(VectorDisplacement 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.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
boolean	getConserveDistanceForAberration() Gets a value indicating whether to only correct for the direction of the vector and not its magnitude when computing the aberration due to relative motion of the observer with respect to the target.
SignalDirection	getDirection() Gets the direction in which the signal travels with respect to the initial point.
VectorEvaluator	getEvaluator(EvaluatorGroup group) Gets an evaluator that can be used to find the relative Motion<Cartesian> between the InitialPoint (get / set) and FinalPoint (get / set) in InitialPoint (get / set)'s ReferenceFrame at a given JulianDate.
ReferenceFrame	getInertialFrame() Gets the inertial frame in which the light path is modeled.
double	getLightTravelTimeConvergenceTolerance() Gets the tolerance required to indicate convergence of the light travel time adjustment.
LinkDelayEvaluator	getLightTravelTimeEvaluator() Gets an evaluator that evaluates the light travel time between the two points involved in this displacement vector.
LinkDelayEvaluator	getLightTravelTimeEvaluator(EvaluatorGroup group) Gets an evaluator that evaluates the light travel time between the two points involved in this displacement vector.
VectorVelocity	getVelocityOfMovingFrame() Gets the velocity of the moving frame in which the affect of aberration is to be determined.
void	setConserveDistanceForAberration(boolean value) Sets a value indicating whether to only correct for the direction of the vector and not its magnitude when computing the aberration due to relative motion of the observer with respect to the target.
void	setDirection(SignalDirection value) Sets the direction in which the signal travels with respect to the initial point.
void	setInertialFrame(ReferenceFrame value) Sets the inertial frame in which the light path is modeled.
void	setLightTravelTimeConvergenceTolerance(double value) Sets the tolerance required to indicate convergence of the light travel time adjustment.
void	setVelocityOfMovingFrame(VectorVelocity value) Sets the velocity of the moving frame in which the affect of aberration is to be determined.

Methods inherited from class agi.foundation.geometry.VectorDisplacement

checkForSameDefinition, getFinalPoint, getInitialPoint, setFinalPoint, setInitialPoint

Methods inherited from class agi.foundation.geometry.Vector

add, add, checkForSameDefinition, createVectorDerivative, cross, divide, divide, divide, divide, dot, getEvaluator, getScalarElement, getScalarElement, getService, multiply, multiply, multiply, multiply, multiply, multiply, subtract, subtract

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

Field Detail

DefaultLightTimeConvergenceTolerance

public static final double DefaultLightTimeConvergenceTolerance

The default tolerance required to indicate convergence of the light travel time adjustment.

See Also:

Constant Field Values

Constructor Detail

VectorApparentDisplacement

public VectorApparentDisplacement()

Initializes a new instance. The user must set InertialFrame (get / set), InitialPoint (get / set), FinalPoint (get / set) so that the apparent displacement accounting for light travel time can be modeled. Optionally, the user must set the VelocityOfMovingFrame (get / set) in order to model the affect of aberration on the apparent displacement. LightTravelTimeConvergenceTolerance (get / set) is initialized to 5E-5. Direction (get / set) is initialized to SignalDirection.RECEIVE. VelocityOfMovingFrame (get / set) is uninitialized.

VectorApparentDisplacement

public VectorApparentDisplacement(Point initialPoint,
                                  Point finalPoint,
                                  ReferenceFrame inertialFrame,
                                  @Nonnull
                                  SignalDirection direction,
                                  double lightTravelTimeConvergenceTolerance,
                                  VectorVelocity velocityOfMovingFrame)

Initializes a new instance of the VectorApparentDisplacement class which accounts for aberration in addition to light travel time.

Parameters:

initialPoint - The initial point.

finalPoint - The final point.

inertialFrame - The inertial frame in which the light path is modeled.

direction - The direction in which the signal travels with respect to the initial point.

lightTravelTimeConvergenceTolerance - The tolerance required to indicate convergence of the light travel time adjustment.

velocityOfMovingFrame - The velocity of the moving frame in which the affect of aberration is to be determined.

VectorApparentDisplacement

public VectorApparentDisplacement(Point initialPoint,
                                  Point finalPoint,
                                  ReferenceFrame inertialFrame,
                                  @Nonnull
                                  SignalDirection direction,
                                  double lightTravelTimeConvergenceTolerance)

Initializes a new instance of the VectorApparentDisplacement class which only accounts for light travel time.

Parameters:

initialPoint - The initial point.

finalPoint - The final point.

inertialFrame - The inertial frame in which the light path is modeled.

direction - The direction in which the signal travels with respect to the initial point.

lightTravelTimeConvergenceTolerance - The tolerance required to indicate convergence of the light travel time adjustment.

VectorApparentDisplacement

public VectorApparentDisplacement(Point initialPoint,
                                  Point finalPoint,
                                  ReferenceFrame inertialFrame,
                                  VectorVelocity velocityOfMovingFrame)

Initializes a new instance of the VectorApparentDisplacement class which accounts for aberration in addition to light travel time.

• Direction (get / set) = SignalDirection.RECEIVE
• LightTravelTimeConvergenceTolerance (get / set) = 5E-5

Parameters:

initialPoint - The initial point.

finalPoint - The final point.

inertialFrame - The inertial frame in which the light path is modeled.

velocityOfMovingFrame - The velocity of the moving frame in which the affect of aberration is to be determined.

VectorApparentDisplacement

public VectorApparentDisplacement(Point initialPoint,
                                  Point finalPoint,
                                  ReferenceFrame inertialFrame)

Initializes a new instance of the VectorApparentDisplacement class which only accounts for light travel time.

• Direction (get / set) = SignalDirection.RECEIVE
• LightTravelTimeConvergenceTolerance (get / set) = 5E-5

Parameters:

initialPoint - The initial point.

finalPoint - The final point.

inertialFrame - The inertial frame in which the light path is modeled.

VectorApparentDisplacement

protected VectorApparentDisplacement(@Nonnull
                                     VectorApparentDisplacement 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(VectorDisplacement 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 VectorDisplacement

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(VectorApparentDisplacement 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 VectorApparentDisplacement.checkForSameDefinition(agi.foundation.geometry.VectorDisplacement) method.

Overrides:

computeCurrentDefinitionHashCode in class VectorDisplacement

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 VectorDisplacement

Parameters:

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

getInertialFrame

public final ReferenceFrame getInertialFrame()

Gets the inertial frame in which the light path is modeled.

setInertialFrame

public final void setInertialFrame(ReferenceFrame value)

Sets the inertial frame in which the light path is modeled.

getDirection

@Nonnull
public final SignalDirection getDirection()

Gets the direction in which the signal travels with respect to the initial point.

setDirection

public final void setDirection(@Nonnull
                               SignalDirection value)

Sets the direction in which the signal travels with respect to the initial point.

getLightTravelTimeConvergenceTolerance

public final double getLightTravelTimeConvergenceTolerance()

Gets the tolerance required to indicate convergence of the light travel time adjustment.

setLightTravelTimeConvergenceTolerance

public final void setLightTravelTimeConvergenceTolerance(double value)

Sets the tolerance required to indicate convergence of the light travel time adjustment.

getVelocityOfMovingFrame

public final VectorVelocity getVelocityOfMovingFrame()

Gets the velocity of the moving frame in which the affect of aberration is to be determined.

setVelocityOfMovingFrame

public final void setVelocityOfMovingFrame(VectorVelocity value)

Sets the velocity of the moving frame in which the affect of aberration is to be determined.

getConserveDistanceForAberration

public final boolean getConserveDistanceForAberration()

Gets a value indicating whether to only correct for the direction of the vector and not its magnitude when computing the aberration due to relative motion of the observer with respect to the target.

setConserveDistanceForAberration

public final void setConserveDistanceForAberration(boolean value)

Sets a value indicating whether to only correct for the direction of the vector and not its magnitude when computing the aberration due to relative motion of the observer with respect to the target.

getEvaluator

public VectorEvaluator getEvaluator(EvaluatorGroup group)

Gets an evaluator that can be used to find the relative Motion<Cartesian> between the InitialPoint (get / set) and FinalPoint (get / set) in InitialPoint (get / set)'s ReferenceFrame at a given JulianDate.

Specified by:

getEvaluator in class Vector

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:

An evaluator for this vector.

Throws:

PropertyInvalidException - Thrown when a property InertialFrame (get / set), InitialPoint (get / set), or FinalPoint (get / set) is not initialized.

getLightTravelTimeEvaluator

public final LinkDelayEvaluator getLightTravelTimeEvaluator()

Gets an evaluator that evaluates the light travel time between the two points involved in this displacement vector. If the input JulianDate to the evaluator represents the moment of an event at the InitialPoint (get / set), the returned Duration is the time until the event will be observed at the FinalPoint (get / set).

If the Direction (get / set) of this vector is SignalDirection.TRANSMIT, the returned duration will always be positive or zero. If the Direction (get / set) of this vector is SignalDirection.RECEIVE, the returned duration will always be negative or zero. The JulianDate at which the event is observed at the FinalPoint (get / set) can be obtained by adding the Duration returned by the evaluator to original JulianDate passed to the Evaluate method.

Returns:

The evaluator.

getLightTravelTimeEvaluator

@Nonnull
public final LinkDelayEvaluator getLightTravelTimeEvaluator(@Nonnull
                                                                      EvaluatorGroup group)

Gets an evaluator that evaluates the light travel time between the two points involved in this displacement vector. If the input JulianDate to the evaluator represents the moment of an event at the InitialPoint (get / set), the returned Duration is the time until the event will be observed at the FinalPoint (get / set).

If the Direction (get / set) of this vector is SignalDirection.TRANSMIT, the returned duration will always be positive or zero. If the Direction (get / set) of this vector is SignalDirection.RECEIVE, the returned duration will always be negative or zero. The JulianDate at which the event is observed at the FinalPoint (get / set) can be obtained by adding the Duration returned by the evaluator to original JulianDate passed to the Evaluate method.

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.