public class SpaceControlFacilityAtmosphericRefractionModel extends AtmosphericRefractionModel
The SCF method uses different ways of determining the refraction angle, depending on the elevation. For elevation angles between 90 and 1.5 deg refraction is computed analytically,
while between 1.5 and -0.72 deg a table interpolation is performed. At the transitions between these elevation angle ranges, the SCF model may show small discontinuities in the refraction angle.
For elevation angles less than -0.72 deg, the refraction value for -0.72 deg elevation is used.
Like the ItuRP834Version4AtmosphericRefractionModel
model, the model does not provide a manner for computing the refraction angle δ at the higher platform H.
The same approximation method as used by the ITU model is used for computing δ.
Modifier | Constructor and Description |
---|---|
|
SpaceControlFacilityAtmosphericRefractionModel()
Initializes a new instance.
|
|
SpaceControlFacilityAtmosphericRefractionModel(CentralBody centralBody)
Initializes a new instance.
|
protected |
SpaceControlFacilityAtmosphericRefractionModel(SpaceControlFacilityAtmosphericRefractionModel 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(SpaceControlFacilityAtmosphericRefractionModel 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.
|
boolean |
getExtrapolateBelowMinimumAltitude()
Gets a value indicating whether to extrapolate below the minimum altitude.
|
double |
getKneeBendFactor()
Gets the knee bend factor.
|
double |
getMinimumAltitude()
Gets the minimum altitude.
|
double |
getRefractionCeiling()
Gets the refraction ceiling.
|
double[] |
getSurfaceRefractivityPolynomialCoefficients()
Gets the surface refractivity polynomial coefficients.
|
void |
setAtmosphereAltitude(double value)
Sets the maximum altitude.
|
void |
setExtrapolateBelowMinimumAltitude(boolean value)
Sets a value indicating whether to extrapolate below the minimum altitude.
|
void |
setKneeBendFactor(double value)
Sets the knee bend factor.
|
void |
setMinimumAltitude(double value)
Sets the minimum altitude.
|
void |
setRefractionCeiling(double value)
Sets the refraction ceiling.
|
void |
setSurfaceRefractivityPolynomialCoefficients(double[] value)
Sets the surface refractivity polynomial coefficients.
|
checkForSameDefinition, enumerateDependencies, getCentralBody, setCentralBody, validateProperties
areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, freezeAggregatedObjects, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen
public SpaceControlFacilityAtmosphericRefractionModel()
public SpaceControlFacilityAtmosphericRefractionModel(CentralBody centralBody)
centralBody
- The central body to which the refraction model applies.protected SpaceControlFacilityAtmosphericRefractionModel(@Nonnull SpaceControlFacilityAtmosphericRefractionModel 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 ICloneWithContext
clone
in class DefinitionalObject
context
- 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 AtmosphericRefractionModel
other
- The other instance to compare to this one.true
if the two objects are defined equivalently; otherwise false
.protected boolean checkForSameDefinition(SpaceControlFacilityAtmosphericRefractionModel 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()
SpaceControlFacilityAtmosphericRefractionModel.checkForSameDefinition(agi.foundation.celestial.AtmosphericRefractionModel)
method.computeCurrentDefinitionHashCode
in class AtmosphericRefractionModel
public 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 object 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 object 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 final double getMinimumAltitude()
For platforms at low altitudes (e.g., less than 5 km), the refraction angle computed by the SCF model is a poor approximation to reality.
If the higher platform's altitude is below the minimum altitude, then the SCF model does not apply.In such cases, if ExtrapolateBelowMinimumAltitude
(get
/ set
) is set to false,
then the refraction angle is set to 0.0 deg.
public final void setMinimumAltitude(double value)
For platforms at low altitudes (e.g., less than 5 km), the refraction angle computed by the SCF model is a poor approximation to reality.
If the higher platform's altitude is below the minimum altitude, then the SCF model does not apply.In such cases, if ExtrapolateBelowMinimumAltitude
(get
/ set
) is set to false,
then the refraction angle is set to 0.0 deg.
public final boolean getExtrapolateBelowMinimumAltitude()
If extrapolation is enabled, then the refraction angle will still be computed when the higher platform is below the minimum altitude using a modified approach. In this approach, the higher platform H will be replaced in the computation by the point P, located along the line LH at the point where the (approximate) altitude is the minimum altitude (P will be located past H along LH).
public final void setExtrapolateBelowMinimumAltitude(boolean value)
If extrapolation is enabled, then the refraction angle will still be computed when the higher platform is below the minimum altitude using a modified approach. In this approach, the higher platform H will be replaced in the computation by the point P, located along the line LH at the point where the (approximate) altitude is the minimum altitude (P will be located past H along LH).
public final double[] getSurfaceRefractivityPolynomialCoefficients()
The coefficients of the polynomial η = C0 + C1^t + C2t^2 + ... + Cnt^n used to approximate the surface refractivity over time, where t is the current epoch, expressed as a fraction of the current year (so that t is 0.0 at the start of the year and 1.0 at the end of the year).
public final void setSurfaceRefractivityPolynomialCoefficients(double[] value)
The coefficients of the polynomial η = C0 + C1^t + C2t^2 + ... + Cnt^n used to approximate the surface refractivity over time, where t is the current epoch, expressed as a fraction of the current year (so that t is 0.0 at the start of the year and 1.0 at the end of the year).
public VectorEvaluator getEvaluator(EvaluatorGroup group, VectorDisplacement unrefractedDisplacementVector)
getEvaluator
in class AtmosphericRefractionModel
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.unrefractedDisplacementVector
- The unrefracted displacement vector which will be refracted.ArgumentNullException
- Thrown when group
or unrefractedDisplacementVector
is null
.PropertyInvalidException
- Thrown when any one of the RefractionCeiling
(get
/ set
), AtmosphereAltitude
(get
/ set
), or MinimumAltitude
(get
/ set
) is
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.PropertyInvalidException
- Thrown when the property SurfaceRefractivityPolynomialCoefficients
(get
/ set
) is a null or has a count of zero.