agi.foundation.navigation.advanced

(agi.foundation.navigation-2024r3.jar)

Class NavigationSignal

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.navigation.advanced.NavigationSignal

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class NavigationSignal
extends DefinitionalObject

A navigation signal that is trackable by a GPS receiver.

Constructor Summary

Constructors

Constructor and Description
NavigationSignal(NavigationSignalType signalType, NavigationSignalPriority priority, NavigationSignalTrackingType tracking, int satelliteID, double carrierToNoiseThreshold) Constructs a trackable signal for a navigation communications front end, specifying all parameters except the link.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(DefinitionalObject other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(NavigationSignal 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.
double	getCarrierToNoiseThreshold() Gets the carrier to noise value below which this signal cannot be tracked.
ExtensibleObject	getChannelLink() Gets the link connecting this channel to the satellite's transmitter.
NavigationSignalPriority	getPriority() Gets the priority of this signal, used when more than one NavigationSignal is available.
int	getSatelliteID() Gets the ID of the navigation satellite broadcasting this signal.
NavigationSignalType	getSignalType() Gets this signal's type.
NavigationSignalTrackingType	getTracking() Gets this signal's role: as a starting signal in the channel, or a maintaining signal.
void	setCarrierToNoiseThreshold(double value) Sets the carrier to noise value below which this signal cannot be tracked.
void	setChannelLink(ExtensibleObject value) Sets the link connecting this channel to the satellite's transmitter.
void	setPriority(NavigationSignalPriority value) Sets the priority of this signal, used when more than one NavigationSignal is available.
void	setSatelliteID(int value) Sets the ID of the navigation satellite broadcasting this signal.
void	setSignalType(NavigationSignalType value) Sets this signal's type.
void	setTracking(NavigationSignalTrackingType value) Sets this signal's role: as a starting signal in the channel, or a maintaining signal.

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

NavigationSignal

public NavigationSignal(@Nonnull
                        NavigationSignalType signalType,
                        @Nonnull
                        NavigationSignalPriority priority,
                        @Nonnull
                        NavigationSignalTrackingType tracking,
                        int satelliteID,
                        double carrierToNoiseThreshold)

Constructs a trackable signal for a navigation communications front end, specifying all parameters except the link.

The ChannelLink (get / set) is set by the GpsCommunicationsFrontEnd, when used in a GpsReceiver.

Parameters:

signalType - The signal type to track.

priority - Priority of this signal, when more than one signal is present.

tracking - The tracking type for this signal.

satelliteID - The ID for the satellite generating this signal. This can be any number, it is replaced by the actual ID when a navigation communications front end is constructed.

carrierToNoiseThreshold - Value below which this signal cannot be tracked

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(DefinitionalObject 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 DefinitionalObject

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(NavigationSignal 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 NavigationSignal.checkForSameDefinition(agi.foundation.infrastructure.DefinitionalObject) method.

Overrides:

computeCurrentDefinitionHashCode in class DefinitionalObject

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.

getTracking

@Nonnull
public final NavigationSignalTrackingType getTracking()

Gets this signal's role: as a starting signal in the channel, or a maintaining signal.

In GpsCommunicationsFrontEnds that use L1 CA to initialize tracking, then switch to L1 PY and L2 PY, their L1 CA NavigationSignal would be set to NavigationSignalTrackingType.STARTING, while the L1 PY and L2 PY NavigationSignal would be set to NavigationSignalTrackingType.MAINTAINING.

setTracking

public final void setTracking(@Nonnull
                              NavigationSignalTrackingType value)

Sets this signal's role: as a starting signal in the channel, or a maintaining signal.

In GpsCommunicationsFrontEnds that use L1 CA to initialize tracking, then switch to L1 PY and L2 PY, their L1 CA NavigationSignal would be set to NavigationSignalTrackingType.STARTING, while the L1 PY and L2 PY NavigationSignal would be set to NavigationSignalTrackingType.MAINTAINING.

getSignalType

@Nonnull
public final NavigationSignalType getSignalType()

Gets this signal's type.

setSignalType

public final void setSignalType(@Nonnull
                                NavigationSignalType value)

Sets this signal's type.

getCarrierToNoiseThreshold

public final double getCarrierToNoiseThreshold()

Gets the carrier to noise value below which this signal cannot be tracked.

setCarrierToNoiseThreshold

public final void setCarrierToNoiseThreshold(double value)

Sets the carrier to noise value below which this signal cannot be tracked.

getPriority

@Nonnull
public final NavigationSignalPriority getPriority()

Gets the priority of this signal, used when more than one NavigationSignal is available.

setPriority

public final void setPriority(@Nonnull
                              NavigationSignalPriority value)

Sets the priority of this signal, used when more than one NavigationSignal is available.

getChannelLink

public final ExtensibleObject getChannelLink()

Gets the link connecting this channel to the satellite's transmitter.

setChannelLink

public final void setChannelLink(ExtensibleObject value)

Sets the link connecting this channel to the satellite's transmitter.

getSatelliteID

public final int getSatelliteID()

Gets the ID of the navigation satellite broadcasting this signal.

setSatelliteID

public final void setSatelliteID(int value)

Sets the ID of the navigation satellite broadcasting this signal.