agi.foundation.communications.antennas

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

Class GaussianOpticalGainPattern

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.communications.antennas.BaseGainPattern

agi.foundation.communications.antennas.OpticalGainPattern

agi.foundation.communications.antennas.GaussianOpticalGainPattern

All Implemented Interfaces:

IAntennaEfficiencyService, IAntennaGainService, ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable, IServiceProvider

public class GaussianOpticalGainPattern
extends OpticalGainPattern
implements IAntennaEfficiencyService

A static gain pattern for an optical antenna with a gaussian profile.

The gain pattern is modeled using the equation G(theta) = Gmax * exp(-8.0 * (theta + pointingError)^2 / divAngle^2) where Gmax is computed using the static GaussianOpticalGainPattern.computeMaximumGain(double, double, double) method and divAngle is the divergence angle returned from the DivergenceAngle (get / set) property. The antenna gain is only applied to signals which reside in the frequency band from CommunicationsConstants.MinimumOpticalFrequency to CommunicationsConstants.MaximumOpticalFrequency.

Constructor Summary

Constructors

Modifier	Constructor and Description
	GaussianOpticalGainPattern() Initializes a new instance.
	GaussianOpticalGainPattern(double apertureDiameter, double divergenceAngle, double efficiency, double pointingError) Create a new instance based on the given aperture diameter, divergence angle, efficiency, and pointing error.
protected	GaussianOpticalGainPattern(GaussianOpticalGainPattern 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(GaussianOpticalGainPattern other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(OpticalGainPattern 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.
static double	computeMaximumGain(double apertureDiameter, double efficiency, double wavelength) Computes the maximum antenna gain using the equation (4 * PI * ApertureArea * Efficiency) / wavelength^2.
SignalEvaluator	getApplyAntennaGainEvaluator(EvaluatorGroup group, Vector linkDirection, Axes antennaAxes, ISignalSource inputSignal, SignalPropagationGraph graph) Get an evaluator which can modify a set of signals based on link geometry and this gain pattern.

Methods inherited from class agi.foundation.communications.antennas.OpticalGainPattern

checkForSameDefinition, getApertureDiameter, getDivergenceAngle, getEfficiency, getPointingError, setApertureDiameter, setDivergenceAngle, setEfficiency, setPointingError, validateProperties

Methods inherited from class agi.foundation.communications.antennas.BaseGainPattern

checkForSameDefinition, getAntennaGainEvaluator, getAntennaGainEvaluator, getService

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, enumerateDependencies, 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

Methods inherited from interface agi.foundation.communications.antennas.IAntennaEfficiencyService

getEfficiency

Constructor Detail

GaussianOpticalGainPattern

public GaussianOpticalGainPattern()

Initializes a new instance.

GaussianOpticalGainPattern

public GaussianOpticalGainPattern(double apertureDiameter,
                                  double divergenceAngle,
                                  double efficiency,
                                  double pointingError)

Create a new instance based on the given aperture diameter, divergence angle, efficiency, and pointing error.

Parameters:

apertureDiameter - The diameter of the optical circular aperture, in meters.

divergenceAngle - The beam divergence angle, in radians. Typically represents the angle at which the gain is 1/e² below the on axis (boresight) value.

efficiency - The efficiency of the optical antenna.

pointingError - The pointing error angle, in radians, for the optical antenna. The pointing error angle is defined as a constant offset which is added to the off-boresight angle, when computing the gain value. The off-boresight angle is the angle between the boresight vector and the link direction vector.

GaussianOpticalGainPattern

protected GaussianOpticalGainPattern(@Nonnull
                                     GaussianOpticalGainPattern 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(OpticalGainPattern 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 OpticalGainPattern

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(GaussianOpticalGainPattern 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 GaussianOpticalGainPattern.checkForSameDefinition(agi.foundation.communications.antennas.OpticalGainPattern) method.

Overrides:

computeCurrentDefinitionHashCode in class OpticalGainPattern

Returns:

The computed hash code.

computeMaximumGain

public static double computeMaximumGain(double apertureDiameter,
                                        double efficiency,
                                        double wavelength)

Computes the maximum antenna gain using the equation (4 * PI * ApertureArea * Efficiency) / wavelength^2. ApertureArea is computed as (PI * ApertureDiameter^2) / 4

Parameters:

apertureDiameter - The diameter of the optical circular aperture.

efficiency - The efficiency of the optical antenna.

wavelength - The wavelength of interest.

Returns:

The computed maximum on axis optical gain.

getApplyAntennaGainEvaluator

public SignalEvaluator getApplyAntennaGainEvaluator(EvaluatorGroup group,
                                                    Vector linkDirection,
                                                    Axes antennaAxes,
                                                    ISignalSource inputSignal,
                                                    SignalPropagationGraph graph)

Get an evaluator which can modify a set of signals based on link geometry and this gain pattern.

Specified by:

getApplyAntennaGainEvaluator in interface IAntennaGainService

Specified by:

getApplyAntennaGainEvaluator in class BaseGainPattern

Parameters:

group - The evaluator group in which to create the evaluator.

linkDirection - The direction of the link relative to the antenna axes.

antennaAxes - The orientation of the antenna.

inputSignal - The source of the input signal to modify.

graph - The graph of communication links to use in the analysis.

Returns:

An evaluator which produces a modified set of signals with gains applied.

Throws:

ArgumentNullException - Thrown when group, linkDirection, antennaAxes, inputSignal, or graph is null.

PropertyInvalidException - Thrown if ApertureDiameter (get / set) or DivergenceAngle (get / set) is not positive, or if PointingError (get / set) is not greater than zero, or if Efficiency (get / set) is not between 0 and 1.