Configuring Parameters of Volcano Minicell Model

4.1 Configuring Parameters of Volcano Model

4.1.2 Configuring Parameters of Volcano Minicell Model

In U-Net, in the Explorer window, in the Modules tab, in the unfolded Propagation Models list, right-click the Volcao Minicell model. Select Properties. You can configure its properties in the mini properties window.

22 Parameters in General Tab

You can configure the name and description information of the model, similar to these of SPM.

Figure 1.1 Parameters in General Tab for Volcano Miniocell model

23 Parameters in Map Data Tab

You can configure the parameters related to map used in model and map-related aspects, as shown in 4.1.2.

Figure 1.1 Parameters in Map data tab for Volcano Microcell model

Vertical analysis mode: it indicates whether the height information about clutters is from 3D raster map (raster favorite) or 3D vector map (vector favorite). If you use 2D vector map without height information about clutters, you shall select raster favorite.

Map data layers: the digital map used by the model. You shall import layers into Volcano model respectively. The layers are usually consistent with the imported digital maps in U-Net.

Altimetry: raster map of terrain height. In digital maps, it is contained in the index file under the heights or DTM directory.

Clutter: raster map of clutter type. In digital maps, it is contained in the index file under the clutter or DLU directory.

Clutter height: raster map of clutter height. In digital maps, it is contained in the index file under the building or DHM directory.

2DVector/3D Vector: 2D/3D vector map. In digital maps, it is contained in the index file under the vector directory. The vector map in Volcano Microcell model is mandatory, and at least the 2D vector map is mandatory.

Vector reference: it is valid only when 3D vector map is imported. It indicates whether the height reference of vector map is ground (relative height) or sea surface (absolute height). Its reference is usually ground.

Prediction Preferences: it is valid only when the import map contains various resolutions, such as 20 m and 5 m. It indicates the preferential resolution.

24 Parameters in Clutters Tab

You can configure clutter parameters in raster map in Clutter tab, as shown in 4.1.2.

Figure 1.1 Parameters in Clutters Tab for Volcano Minicell model

When you import the raster map of clutter type (DLU), you can see various clutters in the Clutter tab. Volcano Minicell model describes raster maps from the following aspects:

 Volcano type: the clutter type defined in Volcano. The clutter types are Land, Water, Building, Vegetation, Bridge and Built-up area.

These six clutter types use different calculation strategies. You shall select corresponding volcano type according to the definitions of clutter types in digital maps.

 Clutter attenuation: the clutter loss. Each volcano type has a default clutter attenuation, but you can change it.

 Building Linear Loss: linear loss of buildings. You can configure it for the clutter of building type. It is 0.5 dB/m by default. If you do not consider linear loss of buildings, you can configure it to 0.

In Volcano Minicell model, the penetration loss of buildings includes two parts: clutter attenuation and building linear loss, but in SPM, there is loss per clutter class only. To make Volcano model and SPM compatible, you can configure the clutter attenuation of Volcano consistent with losses per clutter class of SPM while you configure building linear loss to 0. In this way, SPM and Volcano model have same indoor penetration loss.

25 Parameters in Vectors Tab

You can configure vector parameters of vector maps in the Vectors tab, as shown in 4.1.2. If you use 2D vector map or no vector map, this tab is invalid.

Figure 1.1 Parameters in vectors tab for Volcano Minicell model

When importing a vector map, you can see various clutter types in the Vectors tab. Volcano Macrocell model describes vector properties from the following aspects:

 Volcano type: the vector type defined in Volcano model. The Volcano types are Land, Water, Building, Vegetation and Bridge.

These five clutter types use different calculation strategies. You shall select

corresponding volcano type according to the definitions of vector types in digital maps.

 Clutter attenuation: the clutter loss. Each volcano type has a default clutter loss, but you can change it.

 Building Linear Loss: linear loss of buildings You can configure it for the clutter of building type. It is 0.5 dB/m by default. If you do not consider linear loss of buildings, you can configure it to 0.

NOTE

You must configure volcano type to building in vector maps; otherwise, Volcano Microcell model will not perform multi-path calculation of ray tracing.

If some 2D vector map with 5-meter resolution, the Vectors tab is invalid, gray. For the vector of building type, you shall check whether its volcano type is Building. 4.1.2 shows the correct configuration.

Figure 1.2 Correct configuration of vectors of building type

If the Volcano type (especially the building type) is incorrect in the Vectors tab, you need modify the menu file for vector map by adding #BUILDING at the building type, as shown in 4.1.2. After modification, you need re-import the vector layer.

Figure 1.3 Menu file for vector map

26 Parameter in Ray Tracing Tab

You can configure parameters of ray tracing algorithm for Volcano Minicell model, as shown in 4.1.2.

Figure 1.1 Parameters in Ray Tracing tab for Volcano Minicell model

Launching parameters: the parameters of ray tracing (transmission ray) algorithm used by the Minicell model.

Maximum number of diffractions: maximum number of diffractions, usually configured to 1.

Maximum number of reflections: maximum number of reflections, 2 by default, usually configured to 4.

Angular step: angular step of transmission ray, usually configured to 1°.

Linear step: the distance between transmission rays, usually 4 m.

Ray stopping limits/Width of near region: radius of near region.

27 Parameters in Parameters Tab

You can configure other parameters for Minicell model, as show in 4.1.2.

Figure 1.1 Parameters in Parameter tab for Volcano Minicell model

Free space correction: coefficient for free space correction. You can set two sets of A and B for near region and far region respectively.

Deterministic weighting: weighting factor of deterministic calculation.

Ray-Tracing Weighting: weighting factor of ray tracing calculation. It includes reflection weight, diffraction weight, and backward weight.

You can obtain the values of previous parameters by model tuning.

Indoor penetration: indoor prediction. The "indoor" referred herein is inside buildings of building type.

Tune parameters: you can start model tuning by clicking Tune Parameters button.

In document Model Tuning - Atoll.pdf (Page 74-82)