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TiremPropagationModel3_18 Class

TIREM calculates the propagation loss between antennas on or up to 30 km above the surface of the Earth for frequencies from 1 to 40000 MHz.
Inheritance Hierarchy

Namespace:  AGI.Foundation.Communications.SignalPropagation
Assembly:  AGI.Foundation.Communications (in AGI.Foundation.Communications.dll) Version: 19.3.400.0 (19.3.400.0)
Syntax
public class TiremPropagationModel3_18 : SignalPropagationModel

The TiremPropagationModel3_18 type exposes the following members.

Constructors
  NameDescription
Public methodTiremPropagationModel3_18
Initializes a new instance.
Public methodTiremPropagationModel3_18(TerrainProvider)
Initializes a new instance from the given terrain provider.
Protected methodTiremPropagationModel3_18(TiremPropagationModel3_18, CopyContext)
Initializes a new instance as a copy of an existing instance.
Public methodTiremPropagationModel3_18(TerrainProvider, Double, Double, Double, Double, Double, Boolean, Boolean, Boolean)
Initializes a new instance from the given terrain provider, and sampling step.
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Properties
  NameDescription
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 propertyMaximumAltitude
Gets the model's maximum altitude. The maximum altitude for the TIREM propagation model is 30 km.
Public propertySurfaceConductivity
Gets or sets the conductivity of the earth's surface. The valid range of surface conductivity is 0.00001 to 100.0 Siemens per meter (S/m). This value defaults to 0.005. This scalar will be provided with a service provider providing ILinkService.
Public propertySurfaceHumidity
Gets or sets the humidity of the earth's surface in grams per cubic meter at the transmitter. The valid range of surface humidity is 0.0 to 110.0 grams/m^3. This value defaults to 64.0. This scalar will be provided with a service provider providing ILinkService.
Public propertySurfaceRefractivity
Gets or sets the refractivity of the earth's surface. The valid range of surface refractivity is 200.0 to 450.0 N-units. This value defaults to 310.0. This scalar will be provided with a service provider providing ILinkService.
Public propertySurfaceRelativePermittivity
Gets or sets the relative permittivity of the earth's surface. The valid range of relative permittivity is 1.0 to 100.0. This value defaults to 15.0. This scalar will be provided with a service provider providing ILinkService.
Public propertyTerrainProvider
Gets or sets the terrain provider used in computing loss with the TIREM model.
Public propertyTerrainSamplingStep
Gets or sets the terrain sampling step, in radians. The sampling step must be greater than zero. By default, this value is , and the sampling step will be calculated based on the MinimumSampleSpacing of the configured TerrainProvider. Setting this value will override the sampling step, which will affect the number of samples taken.
Public propertyUseAtmosphericAbsorptionModel
Gets or sets a value indicating whether TIREM Atmospheric Absorption loss is included in the results. This value defaults to true.
Public propertyUseFreeSpaceLossModel
Gets or sets a value indicating whether the TIREM Free Space loss is included in the results. This value defaults to true.
Public propertyUseHorizontalPolarization
Gets or sets a value indicating whether to use horizontal polarization instead of the default vertical polarization setting.
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Methods
  NameDescription
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 SignalPropagationModel.)
Protected methodCheckForSameDefinition(SignalPropagationModel)
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 SignalPropagationModelCheckForSameDefinition(SignalPropagationModel).)
Protected methodCheckForSameDefinition(TiremPropagationModel3_18)
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 SignalPropagationModelComputeCurrentDefinitionHashCode.)
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.
(Overrides DefinitionalObjectEnumerateDependencies(DependencyEnumerator).)
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 methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetSignalPropagator
Get a propagator which can propagate communication signals over the given link.
(Overrides SignalPropagationModelGetSignalPropagator(EvaluatorGroup, IServiceProvider).)
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.)
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Remarks

To use the TIREM Signal Propagation Model, you must have a TIREM Library license and an additional DLL, which customers can request from AGI Support by emailing support@agi.com.

TIREM contains its own versions of signal Free Space loss and Atmospheric Attenuation. STK Components also has versions of these loss models, and the Free Space loss model is turned on by default in the WirelessLinkExtension, and the CommunicationSystem objects. Note that if the Free Space loss or Atmospheric Attenuation models are left on (the default for TIREM), and they are also included in a WirelessLinkExtension, or CommunicationSystem object, an exception will be thrown by those objects - to avoid duplication of signal loss from multiple models. When choosing to use TIREM, decide which Free Space loss and Atmospheric Models you want to use, and adjust the TIREM properties, or the WirelessLinkExtension, or CommunicationSystem objects appropriately.

TIREM (Terrain Integrated Rough Earth Model) examines the terrain profile between the antennas, using the effective Earth radius geometry to determine whether the antennas are within line of sight (LOS) or beyond Line of Sight (BLS) and to find the number, location and extent of sea water bodies along the path. Note that you must ensure you have set the MeanSeaLevel property of the EarthCentralBody for TIREM to work properly. If it is not set, an exception will be thrown.

If LOS, the loss above free space is estimated as the smaller of the reflection region loss due to terrain intrusion into the first Fresnel zone or the spherical Earth loss for an assumed all land path. If there is sea water along the profile, the spherical Earth loss is calculated for an assumed all-sea path using sea water constants. The LOS loss above free space is then taken to be a combination of the all-land loss and all-sea loss weighted by the proportion of land and sea segments along the profile. The total path loss is found as the sum of the LOS loss, the loss due to atmospheric absorption, and the free space loss.

If BLS, the knife edge diffraction losses are found using the Epstein-Peterson method. If these average less than 7 dB, the terrain is regarded as smooth and the diffraction loss above free space is calculated using the spherical Earth model with ground constants for land. If there are bodies of sea water along the profile, the spherical Earth model is used again with sea water constants and the diffraction loss above free space is weighted by the proportion of land and sea segments along the profile. If the average knife edge diffraction loss exceeds 7 dB, the terrain is regarded as rough and the diffraction loss above free space is the sum of the knife edge losses, the reflection region losses that occur between the transmitter and its horizon and the receiver and its horizon (using a method similar to LOS), and (if diffraction occurs on sea water) spherical Earth losses for the sea water segments of the profile. In any case, the loss due to atmospheric absorption and the free space loss are added. Next, the tropospheric-scatter loss is calculated and combined with the atmospheric absorption for the troposcatter geometry. The total path loss is found by comparing the diffraction loss and troposcatter loss and selecting the dominant (noted by the smaller loss) mode.

See Also