RF Channel Modeler Analysis Tab

After generating your transceivers under the Design tab of the Ansys RF Channel Modeler™ plugin, you can then set up the remaining simulation parameters under the Analysis tab. This tab has three sections that cover the following functionality:

Analysis configuration

Use this top panel to instantiate all your analysis configurations. This includes specifying settings with the Analysis Extent Tool and Advanced Solver Options dialog box. As you add analysis configurations, their names appear in the list along with the configuration status of each.

You can add or remove analysis configurations using the following icons.

Option Icon Description
Add Configuration

When you click this icon, choose one of the following configuration types:

  • Communications () - Select this for RF networks.
  • Radar () - Select either ISAR (inverse synthetic aperture radar) or SAR (synthetic aperture radar).

When the Add Configuration dialog box appears, enter a name for the analysis configuration and click OK.

Delete Configuration To remove an analysis configuration from the list, select (highlight) it and click .
Duplicate Configuration To duplicate an analysis configuration in the list, select (highlight) it and click . The Duplicate Configuration dialog box appears. Enter a name for the duplicated analysis configuration, or retain the default name, and click OK. The new analysis configuration now appears in the list.

Analysis Extent Tool

When you click the Analysis Extent Tool icon () in the top panel, the Analysis Extent Tool dialog box appears, enabling you to adjust the physical extent of the analysis area. The tool lists all the analysis configurations available. Use the following parameters in the dialog box to specify the extent.

Item Description
Select All Select this check box to apply your extents adjustments to all of the analysis configurations listed in the dialog box.
Select A check box is available for each analysis configuration. Select the check boxes for the ones you want to include in the extents adjustment.
3D Window Selection - Enable This Enable check box defaults to selected, which enables you to go to the 3D Graphics window and click and drag the extent boundary to adjust it.
North Latitude, West Longitude, South Latitude, East Longitude Enter values for each of these, in degrees, to specify the latitude and longitude boundaries of the analysis region.

After you set all the parameters in the table, click Apply to make all the adjustments.

Advanced Solver Options

When you click the Advanced Solver Options icon () in the top panel, the Advanced Solver Options dialog box appears, enabling you to adjust the settings for the scattering and bouncing rays algorithm for all of the analysis configurations. The table lists all available settings. When you are finished, click OK to apply your settings and close the dialog box.

Setting Description
Enable Geometrical Optics Blockage

The basic SBR+ ray tracing model uses rays only to paint direct currents on the scattering geometry. If you select this check box, the algorithm also computes the following:

  • Blockage of the incident field from the field source by directly illuminated surfaces of the scattering geometry, using a physical optics model
  • Scattering fields arising from interacting with the geometry, using a line-of-sight blockage check to the field observers

If you select the check box, you can choose a Starting Bounce value, either 0 or 1. The default is 1. Starting Bounce is the bounce at which the geometrical optics blockage checks start. Setting the value to 0 also applies geometrical optics blockage checks to the coupling incident field, effectively computing geometrical optics-style direct field instead.

Ray Density

This is a setting for specifying the density of rays as they pass through a sampling box at a given distance from the source. Ansys recommends that you retain the default setting or contact product support for assistance in adjusting this parameter.

Maximum Number of Reflections Enter the maximum number of times that the RF Channel Modeler plugin algorithm will allow a ray to reflect off of an object or facet.
Maximum Number of Transmissions This is the maximum number of penetrable surfaces that the algorithm allows a ray to traverse before ending that ray's track processing.
Bounding Box

This setting limits the area for solver meshing and processing computations to the box window around a target region. Choose one of the following options:

  • Default sets the bounding box to the GPU-SBR default setting.
  • Full Scene sets the bounding box to be the size of the extent of the analysis area.
  • Custom enables you to enter a value for Bounding Box Side Length.

Configuration specification

In the Analysis tab, there are two middle panels. The left panel shows all the applicable Ansys Systems Tool Kit® STK® objects and all the RF Channel Modeler plugin transceivers you added. Use the subtabs in the right panel to set the specifics for the analysis configuration that you highlighted in the top Analysis panel.

Transceivers subtab

Click the Add Transceiver icon () to select transceivers to include in the analysis configuration. When you click the icon, the Add Configuration Analysis Transceivers dialog box appears. You can enable the Select All check box to include all the available transceivers, or you can select individual transceivers by marking the Select check box next to the ones you want. If your Analysis Configuration is a Communications type, then only Communication type transceivers () are available. If your Analysis Configuration is a Radar type, then only Radar type transceivers () are available. For all selected transceivers, you can change them from the default Transceive Mode to TransmitOnly or ReceiveOnly using the Mode drop-down menu. Then click OK to apply the selections and close the dialog box.

After including transceivers, you will see them listed in the Transceivers tab. For each transceiver listed, you can see its name, STK Sensor object path, and associated central body. These are read-only parameters. You can select the Include Parent Facets check box to have the RF Channel Modeler plugin include these facets in the calculations. You can also change the Mode from this list.

To delete a transceiver from the list, select (highlight) it in the list and click the Remove Transceiver icon ().

Image Locations subtab (SAR Radar only)

If you want a SAR image, you must specify the location of its center. You can set and change the location of the center of SAR images using this subtab. Click the Add Image Location icon () to add an entry to the Image Locations list. You can use the RF Channel Modeler-provided name or enter another name. You can change the latitude and longitude of the image location by editing the text fields.

It is often easier and more intuitive to choose your image center locations by selecting points in a scene. If you want to specify latitude and longitude of your existing images using the 3D Graphics window, click the Launch SAR Image Location Tool icon (). The SAR Image Location Tool dialog box appears, listing all the image locations. Select the images for which you want to apply a single location. The 3D Window Selection Enable check box defaults to selected, which enables you to click a point in the 3D Graphics window to specify the latitude and longitude values. Once you click a point in the 3D Graphics window, click Apply to set the location of those selected images to the latitude and longitude in the dialog box.

If you leave the name field blank, enter the same name twice, or enter invalid latitude or longitude data into any cells of an Image Location row, you will see a red error icon appear in the header cell of that row. You must fix this error before running the analysis configuration.

To delete an Image Location from the list, select (highlight) it in the list and click the Remove Image Location icon ().

Target Objects subtab (ISAR Radar only)

Click the Add Radar Target icon () to add an entry to the Target Objects list. When you click the icon, the Add Analysis Configuration Target Objects dialog box appears, enabling you to select objects individually or all at once, using the Select All check box. Click OK to accept your choices and close the dialog box. You can remove an object by highlighting it in the list and clicking the Remove Radar Target icon ().

After including objects, you will see them listed in the Scene Contributor Objects tab. For each object listed, you can see the Object Path, Focused Ray Density, and Central Body as read-only parameters. You can use the Material drop-down menu to select a material type to apply to that target object.

The RF Channel Modeler plugin will check to assure that, for each object you add as a contributor, the object's model in the STK application is type GLB or glTF. This ensures that the model provides surface facets; otherwise, the analysis computation will fail.

If you enter invalid data into any cells of a Scene Contributor Object row, you will see a red error icon appear in the header cell of that row.

Scene Contributor Objects subtab

Click the Add Scene Contributor icon () to add available STK objects to the analysis calculations. When you click the icon, the Add Analysis Scene Contributors dialog box appears, enabling you to select objects individually or all at once, using the Select All check box. Click OK to accept your choices and close the dialog box. You can remove an object by highlighting it in the list and clicking the Remove Scene Contributor icon ().

After including objects, you will see them listed in the Scene Contributor Objects tab. For each object listed, you can see the Object Path, Focused Ray Density, and Central Body as read-only parameters. You can use the Material drop-down menu to select a material type to apply to that scene contributor.

The RF Channel Modeler plugin will check to assure that, for each object you add as a contributor, the object's model in the STK application is type GLB or glTF. This ensures that the model provides surface facets; otherwise, the analysis computation will fail.

If you enter invalid data into any cells of a Scene Contributor Object row, you will see a red error icon appear in the header cell of that row.

Analysis Compute Times subtab

Use this subtab to specify a total analysis interval as well as the step size for analysis calculations. The subtab provides the following settings:

Setting Description
Use Scenario Analysis Interval This check box defaults to selected, which means the analysis calculations will span the entire scenario interval. If you clear this check box, you can specify the analysis interval using the Start Time and Stop Time settings below.
Start Time If you are not using the scenario interval, then enter this time in epoch seconds.
Stop Time If you are not using the scenario interval, then enter this time in epoch seconds.
Continuous Channel Soundings Select this radio button to generate continuous sounding intervals for the entire scenario interval. Thus, the sounding frequency depends on the soundings time step and the number of soundings per time step. This is only available for Communications analysis configurations.
Step Size When you select this radio button, you can enter an analysis step size in seconds or retain the default step size.
Step Count When you select this radio button, you can enter the total number of steps in the analysis interval.

The last three parameters (Continuous Channel Soundings, Step Size, and Step Count) are mutually exclusive. The default is Continuous Channel Soundings for Communications and Step Size for Radar.

Facet Tileset subtab

Facet tilesets represent the structures in the analysis region that can impact the transmitted energy of the channel soundings. Use this tab to specify both analysis extents and facet tilesets.

The Analysis Extent section shows the current extents, which are North Latitude, South Latitude, West Longitude, and East Longitude. You can click Launch Extent Tool to use the Analysis Extent Tool to adjust these extents. You can also select the central body for which the extents apply; the default is to use the central body of the STK application scenario.

The Analysis Extent Graphics section enables you to specify the graphics for the selected analysis cofiguration. You can adjust the following settings:

Setting Description
Show Extent Select this check box to have STK software show the analysis extent in both the 2D and 3D Graphics windows. Selecting this check box activates the remaining settings below.
Select Color Click Select Color to see the Color dialog box, from which you can choose a different color for the extent. The current extent color appears to the left of the button.
Show 3D Label When selected, the 3D Graphics window displays the name of the analysis configuration for the extent area.
Show 2D Label When selected, the 2D Graphics window displays the name of the analysis configuration for the extent area.
Translucency Enter a number from 0.0 to 1.0 to specify the degree of translucency of the extent region. A value of 1.0 makes the region completely opaque.
Top Altitude Enter a value, in meters, for the highest altitude point to display in the extent region.
Bottom Altitude Enter a value, in meters, for the lowest altitude point to display in the extent region.

To select one or more tilesets for inclusion in the analysis configuration, scroll down to the Tilesets section. Click Add to open the Add Facet Tileset dialog box and see a list of available tilesets to add. Each tileset in the list shows the central body to which it applies. To hide the tilesets that have a central body different than the one for the current analysis configuration, select the check box for Hide Incompatible Tilesets. This check box defaults to selected. If you choose to apply a tileset from another central body, you will get a warning message asking if you want to continue. You can select the Select check box to apply one or more of the tilesets, or you can select the Select All check box to apply all tilesets. Click OK to complete your selections and close the dialog box.

To delete a tileset from the list of currently applied tilesets, click it once to highlight it and click Remove.

For each selected tileset, choose a material to represent its reflective characteristics using the drop-down in the Material column. The installed choices are Metal, Absorber, Glass, and Asphalt. You can create additional choices by adding a JSON file to your STK scenario folder. See Custom 3D Tileset Materials.

Imaging Data Products subtab (Radar only)

In the Imaging Data Products tab, first select the Link Name for the link that you want to specify. Then specify the Imaging Data Product Properties and Image Data Product Graphics.

The following parameters appear on the left side of the subtab, under Image Data Products Properties:

Parameter Description
Range Resolution (m) Defines the desired smallest spacing that can be resolved from two scattering sources in range. This is directly related to the radar bandwidth.
Range Window Size (m) Defines the desired image window extent in range. You should set this to a number that is larger than the largest extent of the target/scene.
Cross Range Resolution (m) Defines the desired smallest spacing that can be resolved from two scattering sources in cross-range (related to Doppler). This is directly related to the number of pulses selected for data processing (related to the collection total angular extent).
Cross Range Window Size (m) Defines the desired image window extent in cross-range (related to Doppler). You should set this to a number that is larger than the largest extent of the target/scene.
Required Bandwidth (MHz) This is a calculated field defined by the desired range resolution parameter. It is the minimum bandwidth necessary to achieve the desired range resolution. This is a read-only parameter.
Collection Angle (deg) This is a calculated field defined by the desired cross-range resolution parameter. It is the minimum bandwidth necessary to achieve the desired cross-range resolution. This is a read-only parameter.
Frequency Samples / Pulse This is a calculated field defined by the desired range window size. This ensures that the image will have no range ambiguities due to data processing wrap-around. This is a read-only parameter.
Minimum Pulse Count This is a calculated field defined by the desired cross-range window size. This ensures that the image will have no cross-range ambiguities due to data processing wrap-around. This is a read-only parameter.

The following parameters appear under the Enable Sensor Fixed Distance check box in the Image Data Product Properties section. Select the check box to set these parameters.

Parameter Description
Desired Sensor Fixed Distance (m) This is the desired approximate fixed distance for collection to ensure pulse alignment resulting in a centered image. This overrides the scenario distances.
Center Image in Range Window This check box defaults to selected, meaning that the plots for this analysis configuration will have the image centered in the Range Window that you specify.
Distance to Range Window Start (m) This is the calculated range to the beginning of the image window, based on the desired sensor fixed distance. This is a read-only parameter.
Distance to Range Window Center (m) This is the calculated range to the center of the image window. This is a read-only parameter.

When you select the Enable Range-Doppler Image check box, you can specify the following parameters in the Image Data Product Properties section:

Parameter Description
Range Pixel Count This defines the image pixel resolution in range (display only). It should always be greater than the frequency samples per pulse parameter.
Range Window Type

These are signal processing windowing choices. Choose one of the following options:

  • Flat
  • Hann
  • Hamming
  • Taylor

Flat effectively truncates the data with a square wave. This introduces high-frequency Inverse Fast Fourier Transform (IFFT) artifacts in single-pulse processing that appear as 13 dB sidelobes. The other choices are popular windowing options to help reduce these sidelobes.

Range Window Side Lobe Level (dB down) Enter the value in dB. The default is 1. This parameter is only available if you set Range Window Type to Taylor.
Velocity Pixel Count This defines the image pixel resolution in cross-range (display only). It should always be greater than the minimum pulse count parameter.
Velocity Window Type

These are signal processing windowing choices. Choose one of the following options:

  • Flat
  • Hann
  • Hamming
  • Taylor

Flat effectively truncates the data with a square wave. This introduces high-frequency Inverse Fast Fourier Transform (IFFT) artifacts in single-pulse processing that appear as 13 dB sidelobes. The other choices are popular windowing options to help reduce these sidelobes.

Velocity Window Side Lobe Level (dB down) Enter the value in dB. The default is 1. This parameter is only available if you set Velocity Window Type to Taylor.

When you select the Enable Range-Doppler check box, your only plotting option on the Results tab will be a Range-Doppler image of the transceivers in the Link at each time step.

When you select the Enable Range-Doppler Image check box, then, under the Imaging Data Product Graphics section, you can specify the following parameters:

Parameter Description
Enable Grid Select this check box to have the radar imaging plane appear in the 3D Graphics window as a red rectangular grid relative to the target collection system.
Enable Imaging Select this check box to have the Range-Doppler radar image of the target/location appear on top of the imaging plane.
Plane Offset Enter the fixed distance, in meters, from the radar plane to the radar imaging target/location.
Range Size Enter the height, in meters, of the radar plane in the in-range direction. By selecting the Auto check box, you choose to have the RF Channel Modeler software automatically obtain this range from the Range Window Size parameter, thus replacing this parameter value.
Cross Range Size Enter the width, in meters, of the radar plane in the cross-range direction. By selecting the Auto check box, you choose to have the RF Channel Modeler software automatically obtain this width from the Cross Range Window Size parameter, thus replacing this parameter value.
Range Offset Enter the position offset, in meters, of the grid in the in-range direction relative to the imaging target/location.
Cross Range Offset Enter the position offset, in meters, of the grid in the cross-range direction relative to the imaging target/location.
Translucency Enter a decimal value between 0.0 and 1.0 of the translucency of the range-Doppler image, with 0.0 being completely opaque and 1.0 being completely translucent.
Enable PRF Stretching Select this check box to have RF Channel Modeler software apply a stretching factor to the range-Doppler image based on the radar pulse repetition frequency.
Enable Translucent Response Cutoff Select this check box to have RF Channel Modeler software make translucent in the 3D Graphics window any parts of the range-Doppler image with magnitudes below a cutoff value. You can then specify this cutoff value in dB, or you can select the Auto check box to have the RF Channel Modeler software use the minimum value defined in the Waterfall Properties (defined below) as a cutoff value.
Waterfall Properties Descriptions for these are in the Basic Plot Options section of the Results Tab topic.
Zoom To Click this button to orient the camera such that the radar imaging plane is centered in the 3D Graphics window.

Results Output tab

Click Edit to write an Analysis Description to go with the numerical results of the analysis. Use the Results File Mode drop-down menu to choose the file generation method: single file or one file per link.

Output

At the bottom of the Analysis tab, designate where the RF Channel Modeler plugin sends the results by specifying the Analysis Output Folder path. You can enter a file path or click Select to browse to a folder to select. The data will be in an HDF5 format, as described in the topic page RF Channel Modeler Results File Format.

Running an analysis configuration

When you have finished all setup for an analysis configuration, click Run Analysis at the bottom of the Analysis tab to produce a set of results. You can then go to the Results tab to view these results.