RF Channel Modeler Results File Format
The Ansys RF Channel Modeler™ plugin saves analysis results to a file with the *.rsp file extension in standard HDF5 format. HDF5 is a compact, heterogenous data storage format with metadata documentation. It is natively supported by MATLAB as well as Python libraries. For more information, visit the HDF group website.
You can view HDF5 file contents using following viewers:
The following table provides the format of the results file.
| Group or Dataset Path | Description | Attribute Name | Attribute Unit | Attribute Description | Analysis Type(s) |
|---|---|---|---|---|---|
| / | This is the root file group. | Format version | N/A | This is the version number for the file format. | All |
| Authoring software | N/A | This is the name of the authoring software. | All | ||
| Analysis name | N/A | This is the name of the analysis that produced the results. | All | ||
| Analysis type | N/A | This is the type of analysis. There are three possible types: Communications, Radar SAR, and Radar ISAR. | All | ||
| Analysis DateTime | N/A | This is the date/time at which the analysis began. | All | ||
| Analysis Description | N/A | This is the description of the analysis you entered on the user interface. | All | ||
| /Links | Contains all of the results for each link in the analysis. Each link is a named subgroup under the Links group. The link name contains the transmit transceiver path and the receiver transceiver path. In the case of Radar ISAR, the name also contains the target object name. | N/A | N/A | N/A | All |
| /Links/<link name> | The group for each individual link in the analysis by link name | N/A | N/A | N/A | All |
| /Links/<link name>/Transmitter | Contains transmit transceiver information. | Antenna Count | N/A | This is the number of antenna elements for the transmitting transceiver. | All |
| Name | N/A | This is the transmitting transceiver’s name. | All | ||
| Path | N/A | This is the transmitting transceiver’s path. | All | ||
| /Links/<link name>/Receiver | Contains receive transceiver information. | Antenna Count | N/A | This is the number of antenna elements for the receiving transceiver. | All |
| Name | N/A | This is the receiving transceiver’s name. | All | ||
| Path | N/A | This is the receiving transceiver’s path. | All | ||
| /Links/<link name>/ISAR Target | Contains ISAR target information. | Path | N/A | This is the STK object path of the ISAR target. | Radar ISAR |
| /Links/<link name>/SAR Image Location | Contains SAR image location information | Name | N/A | This is the SAR image location name. | Radar SAR |
| Latitude | Deg | This is the SAR image location latitude. | Radar SAR | ||
| Longitude | Deg | This is the SAR image location longitude. | Radar SAR | ||
| /Links/<link name>/Waveform | Contains transmitted waveform information. | Frequency | Hz | This is the center frequency of the transmitted waveform. | All |
| Bandwidth | Hz | The bandwidth of the transmitted waveform | All | ||
| Channel Soundings | N/A | This is the number of transmitted channel soundings. | Comm | ||
| Sounding Interval | Sec | This is the time interval for each channel sounding. | Comm | ||
| Sample Count | N/A | This is the number of frequency samples per channel sounding. | Comm | ||
| Pulse Repetition Frequency | Hz | This is the pulse repetition frequency of the transmitted waveform. | Radar SAR, Radar ISAR | ||
| /Links/<link name>/ Channel Characterization | Contains all the link channel response information. | Response Type | N/A | This is one of two values: Frequency-Pulse or Range-Doppler. The format of the response array depends on this type. See the "Respnse array format" section below for detailed description of the response array formats. The Range-Doppler response type is only available for the Radar SAR and Radar ISAR analysis types. | All |
| Range Resolution | m | This is the imaging data product range resolution. | Radar SAR, Radar ISAR | ||
| Range Window Size | m | This is the imaging data product range window size. | Radar SAR, Radar ISAR | ||
| Cross Range Resolution | m | This is the imaging data product cross range resolution. | Radar SAR, Radar ISAR | ||
| Cross Range Window Size | m | This is the imaging data product cross range window size. | Radar SAR, Radar ISAR | ||
| Required Bandwidth | Hz | This is the imaging data product required bandwidth. | Radar SAR, Radar ISAR | ||
| Collection Angle | Rad | This is the imaging data product collection angle. | Radar SAR, Radar ISAR | ||
| Frequency Samples Per Pulse | N/A | This is the imaging data product frequency samples per pulse. | Radar SAR, Radar ISAR | ||
| Minimum Pulses Per Image | N/A | This is the imaging data product minimum pulses per image. | Radar SAR, Radar ISAR | ||
| Sensor Fixed Distance Mode | N/A | This is one of two values: Enabled or Disabled. It indicates whether you enabled the Sensor Fixed Distance Mode for the imaging data product. | Radar SAR, Radar ISAR | ||
| Distance To Range Window Center | m | This is the distance to the range window center. It is only written to the file if you enabled the Sensor Fixed Distance Mode. | Radar SAR, Radar ISAR | ||
| Distance To Range Window Start | m | This is the distance to the range window start. It is only written to the file if you enabled the Sensor Fixed Distance Mode. | Radar SAR, Radar ISAR | ||
| Center Image In Range Window | N/A | This is one of two values: Enabled or Disabled. Indicates whether you selected the Center Image in Range Window option. It's only written to the file if you enabled the Sensor Fixed Distance Mode. | Radar SAR, Radar ISAR | ||
| Range Pixel Count | N/A | This is the number of range pixels in the image. It is only written to the file if Response Type is “Range-Doppler”. | Radar SAR, Radar ISAR | ||
| Range Window Type | N/A | This is the range window type for the image. It can be one of four options: Flat, Hann, Hamming, or Taylor. | Radar SAR, Radar ISAR | ||
| Velocity Pixel Count | N/A | This is the number of velocity pixels in the image. It is only written to the file if Response Type is “Range-Doppler”. | Radar SAR, Radar ISAR | ||
| Velocity Window Type | N/A | This is the velocity window type for the image. It can be one of four options: Flat, Hann, Hamming, or Taylor. | Radar SAR, Radar ISAR | ||
| /Links/<link name>/ Channel Characterization/Time Array | Contains array of time samples for the analysis. | N/A | N/A | N/A | All |
| /Links/<link name>/ Channel Characterization/Response | This is the channel response data. It’s an M x N matrix, where M is the number of simulated responses and is equal to length of the time sample array. See the "Response array format" section below for a detailed description of the response array. | N/A | N/A | N/A | All |
| /Links/<link name>/ Channel Characterization/Range Values | This is the pulse-doppler range data. It’s an M x N matrix, where M is the number of simulation groups and is equal to length of the time sample array. N is equal to the number of range pixels given by the Range Pixel Count attribute, which is part of the /Links/<link name>/ Channel Characterization group. The Range Values group is only present in the file if the attribute Response Type is set to Range-Doppler. | N/A | N/A | N/A | Radar SAR, Radar ISAR |
| /Links/<link name>/ Channel Characterization/Velocity Values | This is the pulse-doppler velocity data. It’s an M x N matrix, where M is the number of simulation groups and is equal to length of the time sample array. N is equal to the number of range pixels given by the Velocity Pixel Count attribute, which is part of the “/Links/<link name>/ Channel Characterization” group. The Velocity Values group is only present in the file if the Response Type attribute is set to Range-Doppler. | N/A | N/A | N/A | Radar SAR, Radar ISAR |
| /Links/<link name>/ Channel Characterization/Target Angular Velocity | This is the target angular velocity array. The array is the same length as the number of time samples in the Time Array dataset. Each value in the array is the computed target angular velocity defined in the radar collection reference system. The Target Angular Velocity group is only present in the file if the Response Type attribute is set to Range-Doppler. | N/A | N/A | N/A | Radar SAR, Radar ISAR |
| /Links/<link name>/ Channel Characterization/Pulse Count | This is the image pulse count array. The array is the same length as the number of time samples in the Time Array data set. Each value in the array is the computed pulse count used to produce the image. The pulse count is computed from the radar’s available pulse repetition frequency and target angular velocity value. The Pulse Count group is only present in the file if the Response Type attribute is set to Range-Doppler. | N/A | N/A | N/A | Radar SAR, Radar ISAR |
| /Solver Options | This is the group that contains all the advanced solver options that were configured for the analysis. | Ray Density | rays / wavelength | This is a setting for specifying the density of rays as they pass through a sampling box at a given distance from the source. | All |
| Maximum Number Of Transmissions | N/A | This is the maximum number of penetrable surfaces that the algorithm allows a ray to traverse before ending that ray's track processing. | All | ||
| Maximum Number Of Reflections | N/A | This is the maximum number of times that the algorithm will allow a ray to reflect off of an object or facet. | All | ||
| Geometrical Optics Blockage | N/A |
This has one of two values: Enabled or Disabled. The basic SBR+ ray tracing model uses rays only to paint direct currents on the scattering geometry. If enabled, the algorithm 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 |
All | ||
| Bounding Box | N/A |
This parameter is only applicable for radar modeling. This setting limits the area for solver meshing and processing computations to the box window around a target region. It will be one of the following: 1. Default sets the bounding box to the Perceive EM default setting. 2. Full Scene sets the bounding box to be the size of the extent of the analysis area. 3. Custom enables you to enter a value for Bounding Box Side Length. |
Radar SAR, Radar ISAR | ||
| /Scene | This is the group containing all the scene specific information. | N/A | N/A | N/A | All |
| /Scene/Extent | This is the analysis extent. This group will not be present in the file if the analysis does not contain an extent, which is the case for Radar ISAR. | North | rad | This is the northern latitude of the analysis extent. | Comm, Radar SAR |
| South | rad | This is the southern latitude of the analysis extent. | Comm, Radar SAR | ||
| East | rad | This is the eastern latitude of the analysis extent. | Comm, Radar SAR | ||
| West | rad | This is the western latitude of the analysis extent. | Comm, Radar SAR | ||
| /Scene/Contributors | This is the group that is the root for all the scene contributors in the analysis. This group will not be present in the file if the analysis did not contain scene contributors. | N/A | N/A | N/A | All |
| /Scene/Contributors/<scene contributor name> | This is the group for each scene contributor. The group name is the scene contributor object’s name. | Path | N/A | This is the scenario path for the scene contributor. | All |
| /Scene/Contributors/<scene contributor name>/Material | This is the group containing the material properties information for the scene contributor. | Type | N/A | This is the material type string. “Metal” and “Asphalt” are examples of a material type. | All |
| Properties | N/A | This is the Perceive EM material properties string. | All | ||
Response array format
This section describes the format of the multidimensional response array. The array can have one of two different formats, depending on the response type. The response array is a dataset that has the path /Links/<link name>/ Channel Characterization/Response. To determine how the array is formatted, look at the value of the Response Type attribute of the /Links/<link name>/ Channel Characterization group. Below are descriptions of the format for both cases.
Frequency-Pulse response array
You can determine the Frequency-Pulse response array’s length using the following equation:
N = (Transmit Antennas) * (Receive Antennas) * (Pulses) * (Frequency Samples) * 2
where the following definitions apply:
- Transmit Antennas – This is the number of transmit antennas. You can find it in the file as the This is the attribute of the /Links/<link name>/Transmitter group in all cases: Communications, Radar SAR, and Radar ISAR.
- Receive Antenna – This is the number of receive antennas. You can find it in the file as the Antenna Count attribute of the /Links/<link name>/Receiver group in all cases: Communications, Radar SAR, and Radar ISAR.
- Pulses – This is the number of pulses (Radar) or channel soundings (Comm). For the Radar analysis types (both SAR and ISAR), this value is in the file as the Minimum Pulses Per Image attribute of the /Links/<link name>/Channel Characterization group. For the Communications analysis type, this value is in the files as the Channel Soundings attribute of the /Links/<link name>/Waveform group.
- Frequency Samples – This is the number of frequency samples. For the radar analysis types (both SAR and ISAR), this value is found in the file as the Frequency Samples Per Pulse attribute of the /Links/<link name>/Channel Characterization group. For the Communications analysis type, this value is in the files as the Sample Count attribute of the /Links/<link name>/Waveform group.
The factor 2 in this equation accounts for each frequency sample having both a real and imaginary value stored in consecutive array positions.
Range-Doppler response array
You can only produce the Range-Doppler response when employing the Radar analysis types (both SAR and ISAR). You can determine the array’s length using the following equation:
N = (Transmit Antennas) * (Receive Antennas) * (Velocity Pixels) * (Range Pixels) * 2
where the following definitions apply:
- Transmit Antennas – This is the number of transmit antennas. You can find it in the file as the Antenna Count attribute of the /Links/<link name>/Transmitter group.
- Receive Antenna – This is the number of receive antennas. You can find it in the file as the Antenna Count attribute of the /Links/<link name>/Receiver group.
-
Velocity Pixels – This is the number of velocity pixels. This value is in the file as the Velocity Pixels attribute of the /Links/<link name>/Channel Characterization group.
-
Range Pixels – This is the number of range pixels. This value is in the file as the Range Pixels attribute of the /Links/<link name>/Channel Characterization group.
The factor 2 in this equation accounts for each frequency sample having both a real and imaginary value stored in consecutive array positions.