TiremPropagationModel 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.
TiremPropagationData will be added as data to the Signal as it is propagated.
Namespace: AGI.Foundation.Communications.SignalPropagation
The TiremPropagationModel type exposes the following members.
Name | Description | |
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TiremPropagationModel | Initializes a new instance. | |
TiremPropagationModel(TerrainProvider) |
Initializes a new instance from the given terrain provider.
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TiremPropagationModel(TiremPropagationModel, CopyContext) | Initializes a new instance as a copy of an existing instance. | |
TiremPropagationModel(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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Name | Description | |
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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.) | |
MaximumAltitude |
Gets the model's maximum altitude. The maximum altitude for the TIREM propagation model is 30 km.
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SurfaceConductivity |
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.
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SurfaceHumidity |
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 13.25 grams/m^3.
This value defaults to 4.0.
This scalar will be provided with a service provider providing ILinkService.
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SurfaceRefractivity |
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.
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SurfaceRelativePermittivity |
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.
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TerrainProfileComputation |
Gets or sets the terrain profile computation.
By default, this delegate is , and the terrain profile will be computed automatically.
In unusual situations, this delegate can be provided to have full control over the terrain profile information
which will be provided to the TIREM calculation.
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TerrainProvider |
Gets or sets the terrain provider used in computing loss with the TIREM model.
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TerrainSamplingStep |
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 half of the
MinimumSampleSpacing of the configured TerrainProvider.
Setting this value will override the sampling step, which will affect the number of samples taken.
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UseAtmosphericAbsorptionModel |
Gets or sets a value indicating whether TIREM Atmospheric Absorption loss is included in the results.
This value defaults to true.
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UseFreeSpaceLossModel |
Gets or sets a value indicating whether the TIREM Free Space loss is included in the results.
This value defaults to true.
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UseHorizontalPolarization |
Gets or sets a value indicating whether to use horizontal polarization instead of the default vertical polarization setting.
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Name | Description | |
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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 SignalPropagationModel.) | |
CheckForSameDefinition(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).) | |
CheckForSameDefinition(TiremPropagationModel) |
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).
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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 SignalPropagationModelComputeCurrentDefinitionHashCode.) | |
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.
(Overrides DefinitionalObjectEnumerateDependencies(DependencyEnumerator).) | |
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.) | |
GetHashCode | Serves as the default hash function. (Inherited from Object.) | |
GetSignalPropagator |
Get a propagator which can propagate communication signals over the given link.
(Overrides SignalPropagationModelGetSignalPropagator(EvaluatorGroup, IServiceProvider).) | |
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.) | |
SetNativeLibraryPath | Sets the path of the directory containing the native libraries used by this propagation model. By default, the native libraries will be automatically unpacked to the temporary directory and loaded from there. If that is not desirable for a particular application, this method can be used to bypass the automatic unpacking process. This method must be called before any other calculations are performed using this propagation model. | |
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.) | |
UnloadNativeLibraries |
Unloads the native libraries used by this propagation model, if possible.
Subsequent use of this model will cause the libraries to be loaded again.
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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.
Note that this implementation uses native libraries to perform the calculation. As a result, this implementation only supports 64-bit Windows and Linux platforms. An older implementation, TiremPropagationModel3_18, is also available without these limitations.
TIREM contains its own versions of signal free-space path loss and atmospheric attenuation. DME Component Libraries also has versions of these loss models, and FreeSpacePathLossModel is added by default by WirelessLinkExtension, and CommunicationSystem. Note that WirelessLinkExtension will check to ensure that only one model computes free-space path loss, and throw an exception, to avoid incorrect results. When using TIREM, decide which free-space path loss model you want to use, and either disable the TIREM calculation by setting UseFreeSpaceLossModel, or remove the FreeSpacePathLossModel.
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.