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

SystemObject
  AGI.Foundation.InfrastructureDefinitionalObject
    AGI.Foundation.CelestialAtmosphericRefractionModel
      AGI.Foundation.CelestialItuRP834Version4AtmosphericRefractionModel

Namespace: AGI.Foundation.Celestial
Assembly: AGI.Foundation.Models (in AGI.Foundation.Models.dll) Version: 24.2.419.0 (24.2.419.0)

Syntax

C++

Copy

public class ItuRP834Version4AtmosphericRefractionModel : AtmosphericRefractionModel

Public Class ItuRP834Version4AtmosphericRefractionModel
	Inherits AtmosphericRefractionModel

public ref class ItuRP834Version4AtmosphericRefractionModel : public AtmosphericRefractionModel

type ItuRP834Version4AtmosphericRefractionModel =  
    class
        inherit AtmosphericRefractionModel
    end

The ItuRP834Version4AtmosphericRefractionModel type exposes the following members.

Constructors

	Name	Description
	ItuRP834Version4AtmosphericRefractionModel	Initializes a new instance.
	ItuRP834Version4AtmosphericRefractionModel(CentralBody)	Initializes a new instance.
	ItuRP834Version4AtmosphericRefractionModel(ItuRP834Version4AtmosphericRefractionModel, CopyContext)	Initializes a new instance as a copy of an existing instance.

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Properties

	Name	Description
	AtmosphereAltitude	Gets or sets the maximum altitude.
	CentralBody	Gets or sets the central body that the refraction model is associated with. (Inherited from AtmosphericRefractionModel.)
	IsFrozen	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.)
	KneeBendFactor	Gets or sets the knee bend factor.
	RefractionCeiling	Gets or sets the refraction ceiling.

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Methods

	Name	Description
	CheckForSameDefinition(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).)
	CheckForSameDefinition(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.)
	CheckForSameDefinition(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).
	Clone	Clones this object using the specified context. (Overrides DefinitionalObjectClone(CopyContext).)
	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 CheckForSameDefinition(DefinitionalObject) method. (Overrides AtmosphericRefractionModelComputeCurrentDefinitionHashCode.)
	EnumerateDependencies	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.)
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	Freeze	Freezes this object. Further attempts to modify it will result in an ObjectFrozenException. (Inherited from DefinitionalObject.)
	FreezeAggregatedObjects	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.)
	GetDefinitionHashCode	Gets a hash code representing the definition of this object. (Inherited from DefinitionalObject.)
	GetEvaluator	Gets an evaluator that adjusts the provided displacements relative motion based on atmospheric refraction. (Overrides AtmosphericRefractionModelGetEvaluator(EvaluatorGroup, VectorDisplacement).)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	IsSameDefinition	Determines if this object has the same definition as another object. (Inherited from DefinitionalObject.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ThrowIfFrozen	Throws ObjectFrozenException if this object IsFrozen. This method should be called from any method or property that modifies this object. (Inherited from DefinitionalObject.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)
	ValidateProperties	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.

Reference

AGI.Foundation.Celestial Namespace