public class ItuRP834Version4AtmosphericRefractionModel extends AtmosphericRefractionModel
The model does not provide a method for determining the refraction angle δ at the higher platform H. Rather than performing ray tracing to determine δ,
a simple approximation is used to locate the knee point K. After the refraction angle ε at the lower platform L is determined, the direction from L toward K is known,
although the distance to K is not. Let R be the distance along LH and let d be x% of that distance, where x% is the knee bend distance factor (a percentage specified with KneeBendFactor (get / set)).
Since most of the bending occurs near L, x is small, say 10-20%. The distance d is then used to compute K. If, however, the altitude of K exceeds the atmospheric altitude A,
then d is reduced so that the altitude of K is (approximately) A. This insures that the knee point K lies within the atmosphere. The value of δ computed in this way is likely
to be an over-estimate of the actual refraction angle at H.
| Modifier | Constructor and Description |
|---|---|
|
ItuRP834Version4AtmosphericRefractionModel()
Initializes a new instance.
|
|
ItuRP834Version4AtmosphericRefractionModel(CentralBody centralBody)
Initializes a new instance.
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protected |
ItuRP834Version4AtmosphericRefractionModel(ItuRP834Version4AtmosphericRefractionModel existingInstance,
CopyContext context)
Initializes a new instance as a copy of an existing instance.
|
| Modifier and Type | Method and Description |
|---|---|
protected boolean |
checkForSameDefinition(AtmosphericRefractionModel other)
Checks to determine if another instance has the same definition as this instance and
returns
true if it does. |
protected boolean |
checkForSameDefinition(ItuRP834Version4AtmosphericRefractionModel 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.
|
double |
getAtmosphereAltitude()
Gets the maximum altitude.
|
VectorEvaluator |
getEvaluator(EvaluatorGroup group,
VectorDisplacement unrefractedDisplacementVector)
Gets an evaluator that adjusts the provided displacements relative motion based on atmospheric refraction.
|
double |
getKneeBendFactor()
Gets the knee bend factor.
|
double |
getRefractionCeiling()
Gets the refraction ceiling.
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void |
setAtmosphereAltitude(double value)
Sets the maximum altitude.
|
void |
setKneeBendFactor(double value)
Sets the knee bend factor.
|
void |
setRefractionCeiling(double value)
Sets the refraction ceiling.
|
checkForSameDefinition, enumerateDependencies, getCentralBody, setCentralBody, validatePropertiesareSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, freezeAggregatedObjects, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozenpublic ItuRP834Version4AtmosphericRefractionModel()
public ItuRP834Version4AtmosphericRefractionModel(CentralBody centralBody)
centralBody - The central body to which the refraction model applies.protected ItuRP834Version4AtmosphericRefractionModel(@Nonnull ItuRP834Version4AtmosphericRefractionModel existingInstance, @Nonnull CopyContext context)
See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor
in a derived class.
existingInstance - The existing instance to copy.context - A CopyContext that controls the depth of the copy.ArgumentNullException - Thrown when existingInstance or context is null.public Object clone(CopyContext 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:
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:
CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to
non-evaluators.
IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the
same CopyContext passed to the constructor.
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;clone in interface ICloneWithContextclone in class DefinitionalObjectcontext - The context to use to perform the copy.protected final boolean checkForSameDefinition(AtmosphericRefractionModel other)
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).checkForSameDefinition in class AtmosphericRefractionModelother - The other instance to compare to this one.true if the two objects are defined equivalently; otherwise false.protected boolean checkForSameDefinition(ItuRP834Version4AtmosphericRefractionModel other)
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).other - The other instance to compare to this one.true if the two objects are defined equivalently; otherwise false.protected int computeCurrentDefinitionHashCode()
ItuRP834Version4AtmosphericRefractionModel.checkForSameDefinition(agi.foundation.celestial.AtmosphericRefractionModel) method.computeCurrentDefinitionHashCode in class AtmosphericRefractionModelpublic final double getKneeBendFactor()
The factor used in computing the approximate location of the knee point K.
public final void setKneeBendFactor(double value)
The factor used in computing the approximate location of the knee point K.
public final double getRefractionCeiling()
The maximum altitude of the lower platform for which the refraction angle will be computed. Whenever the lower platform's altitude is above the refraction ceiling, the refraction angle is considered to be 0.0 deg, because little atmosphere is present above this altitude to cause appreciable refraction.
public final void setRefractionCeiling(double value)
The maximum altitude of the lower platform for which the refraction angle will be computed. Whenever the lower platform's altitude is above the refraction ceiling, the refraction angle is considered to be 0.0 deg, because little atmosphere is present above this altitude to cause appreciable refraction.
public final double getAtmosphereAltitude()
The maximum altitude of the knee point K.
public final void setAtmosphereAltitude(double value)
The maximum altitude of the knee point K.
public VectorEvaluator getEvaluator(@Nonnull EvaluatorGroup group, @Nonnull VectorDisplacement unrefractedDisplacementVector)
getEvaluator in class AtmosphericRefractionModelgroup - 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.unrefractedDisplacementVector - The unrefracted displacement vector which will be refracted.ArgumentNullException - Thrown when group or unrefractedDisplacementVector is null.PropertyInvalidException - Thrown when either one of the RefractionCeiling (get / set) or AtmosphereAltitude (get / set) are
set to a value less than or equal to zero.PropertyInvalidException - Thrown when the property CentralBody (get / set) is null.PropertyInvalidException - Thrown when the property KneeBendFactor (get / set) is not in the range 0 to 1.