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ItuRP834Version4AtmosphericRefractionModel Class

ITU-R P.834-4 is the ITU recommendation concerning "Effects of tropospheric refraction on radio wave propagation." The recommendation provides an analytical formula for the refracted elevation at the ground. The higher platform is assumed to be a satellite. More information is available at ITU Radiocommunication Sector. Note that the model does not provide a manner for computing the effect of refraction on the signal path length.
Inheritance Hierarchy

Namespace:  AGI.Foundation.Celestial
Assembly:  AGI.Foundation.Models (in AGI.Foundation.Models.dll) Version: 19.2.399.0 (19.2.399.0)
Syntax
public class ItuRP834Version4AtmosphericRefractionModel : AtmosphericRefractionModel

The ItuRP834Version4AtmosphericRefractionModel type exposes the following members.

Constructors
Properties
  NameDescription
Public propertyAtmosphereAltitude
Gets or sets the maximum altitude.
Public propertyCentralBody
Gets or sets the central body that the refraction model is associated with.
(Inherited from AtmosphericRefractionModel.)
Public propertyIsFrozen
Gets a value indicating whether this object is frozen. A frozen object cannot be modified and an ObjectFrozenException will be thrown if an attempt is made to do so.
(Inherited from DefinitionalObject.)
Public propertyKneeBendFactor
Gets or sets the knee bend factor.
Public propertyRefractionCeiling
Gets or sets the refraction ceiling.
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Methods
  NameDescription
Protected methodCheckForSameDefinition(AtmosphericRefractionModel)
Checks to determine if another instance has the same definition as this instance and returns 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 for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
(Overrides AtmosphericRefractionModelCheckForSameDefinition(AtmosphericRefractionModel).)
Protected methodCheckForSameDefinition(DefinitionalObject)
Checks to determine if another instance has the same definition as this instance and returns 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 for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
(Inherited from AtmosphericRefractionModel.)
Protected methodCheckForSameDefinition(ItuRP834Version4AtmosphericRefractionModel)
Checks to determine if another instance has the same definition as this instance and returns 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 for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IsSameDefinition(Object).
Public methodClone
Clones this object using the specified context.
(Overrides DefinitionalObjectClone(CopyContext).)
Protected methodComputeCurrentDefinitionHashCode
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 CheckForSameDefinition(DefinitionalObject) method.
(Overrides AtmosphericRefractionModelComputeCurrentDefinitionHashCode.)
Public methodEnumerateDependencies
Enumerates the dependencies of this object by calling EnumerateT(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.
(Inherited from AtmosphericRefractionModel.)
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodFreeze
Freezes this object. Further attempts to modify it will result in an ObjectFrozenException.
(Inherited from DefinitionalObject.)
Protected methodFreezeAggregatedObjects
Called by Freeze to also freeze any objects that are considered to be a part of this object. Derived classes which contain additional aggregated objects MUST override this method, call the base implementation, and freeze aggregated objects introduced by the derived class. The objects that need to be frozen in this method are frequently created in this object's constructor and are not settable via properties.
(Inherited from DefinitionalObject.)
Public methodGetDefinitionHashCode
Gets a hash code representing the definition of this object.
(Inherited from DefinitionalObject.)
Public methodGetEvaluator
Gets an evaluator that adjusts the provided displacements relative motion based on atmospheric refraction.
(Overrides AtmosphericRefractionModelGetEvaluator(EvaluatorGroup, VectorDisplacement).)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodIsSameDefinition
Determines if this object has the same definition as another object.
(Inherited from DefinitionalObject.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Protected methodThrowIfFrozen
Throws ObjectFrozenException if this object IsFrozen. This method should be called from any method or property that modifies this object.
(Inherited from DefinitionalObject.)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
Protected methodValidateProperties
Validates that required properties and parameters are configured correctly in order to get an evaluator for this instance. Derived classes should call this method when implementing GetEvaluator(EvaluatorGroup, VectorDisplacement), as well as validate their own properties.
(Inherited from AtmosphericRefractionModel.)
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Remarks
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). 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.
See Also