Radar SearchTrack Constraints
Use the Radar SearchTrack constraint category to impose one or more of the following constraints on a radar object. The "regular" searchtrack parameters correspond to the radar's main channel. These parameters account for the polarization mismatch if you select polarization on the radar object's Basic Definition property page. For more on polarization, see the Polarization Help page. OrthoPol constraints correspond to the radar's orthogonal polarization channel.
Radar Search/Track constraints fall under two types:
See MFR Search/Track constraints for information on Multifunction Radar Search/Track Constraints and Search/Track Constraints with jamming.
Except for the probability of detection (PDet) constraints, Search/Track constraints are available only if Search/Track mode is enabled in the radar's Basic - Definition properties page.
Minimum and Maximum parameters
| Option | Description |
|---|---|
| Dwell Time | Enter Min and/or Max values for the sum of the integration time and RF propagation delays. |
| Integrated PDet | Enter Min and/or Max values in the range 0-1 for the integrated pulse probability of detection. This uses the number of pulses integrated value computed by the radar according to the pulse integration mode. |
| Integrated SNR | Enter Min and/or Max values in the selected ratio unit for the integrated signal-to-noise ratio. This is not available if operating in Goal SNR analysis mode for integration gain. |
| Integration Time | Enter Min and/or Max values for the integration time for the search/track radar required to achieve the goal SNR. This is available only if operating in Goal SNR analysis mode. |
| OrthoPol Dwell Time | Enter Min and/or Max values for the sum of the integration time and RF propagation delays for the orthogonal polarization channel. |
| OrthoPol Integrated PDet | Enter Min and/or Max values in the range 0-1 for the integrated pulse probability of detection for the orthogonal polarization channel. This uses the number of pulses integrated value computed by the radar according to the pulse integration mode. |
| OrthoPol Integrated SNR | Enter Min and/or Max values in the selected ratio unit for the integrated signal-to-noise ratio for the orthogonal polarization channel. This is not available if operating in Goal SNR analysis mode for integration gain. |
| OrthoPol Integration Time | Enter Min and/or Max values for the integration time for the search/track radar required to achieve the goal SNR for the orthogonal polarization channel. This is available only if operating in Goal SNR analysis mode. |
| OrthoPol Pulses Integrated | Enter Min and/or Max quantity for the number of pulses integrated for the orthogonal polarization channel. This is not available for Fixed Pulse Number integration mode. |
| OrthoPol Single Pulse PDet | Enter Min and/or Max values in the range 0-1 for the single-pulse probability of detection for the orthogonal polarization channel. |
| OrthoPol Single Pulse SNR | Enter Min and/or Max values for the single-pulse signal-to-noise ratio for the search/track radar for the orthogonal polarization channel. For a CW radar, the single pulse SNR is the SNR resulting from an effective pulse width of 1 second. |
| Pulses Integrated | Enter Min and/or Max quantity for the number of pulses integrated. This is not available for Fixed Pulse Number integration mode. |
| Single Pulse PDet | Enter Min and/or Max values in the range 0-1 for the single-pulse probability of detection. |
| Single Pulse SNR | Enter Min and/or Max values for the single-pulse signal-to-noise ratio for the search/track radar. For a CW radar, the single pulse SNR is the SNR resulting from an effective pulse width of 1 second. |
| User Plugin | See the User Plugin description section. This option is only available if a plugin is available for use. |
Doppler options
You can also set any or all of the following Doppler constraints:
Doppler constraints
| Option | Description |
|---|---|
| Doppler - MLC Filter | Main lobe clutter bandwidth is the total filter width about the MLC velocity. This constraint denies access when the target Doppler lies within the MLC filter bandwidth. |
| Doppler - Altitude Line Filter | The predominant component of side-lobe clutter for an airborne radar. This constraint denies access if the target Doppler lies within the SLC filter bandwidth. |
| Doppler - Target in Clear Velocity Zone | This constraint denies access unless the target's Doppler return lies above the maximum or below the minimum clutter velocity. It will always deny access for low- and medium-PRF radars and is therefore meaningful only for high-PRF radars. |
| Doppler - Unambiguous Range | Pulse Doppler radars are generally ambiguous in range or Doppler or both. The unambiguous range RU is given by c/2fR, where c is the speed of light and fR is the PRF. This constraint denies access when the range is ambiguous (i.e., it enforces low-PRF mode). |
| Doppler - Unambiguous Velocity | See above. This constraint denies access when the velocity is ambiguous (i.e., it enforces high-PRF mode). |
The MLC Filter constraint has effect only if the MLC Filter is enabled on the Search/Track page of the radar's Basic properties. Similarly, the Altitude Line Filter constraint has effect only if the SLC Filter is enabled.
Radar SearchTrack User Plugin
The User Plugin constraint option extends the Search/Track mode computations. STK interfaces with the plugin script and provides updated object geometry, VGT data and the radar performance data at each time step of the scenario execution. The script uses the STK-supplied data to compute a new parameter and return the value to STK. For more information, see Custom Plugins for Radar Search/Track and SAR Constraints.
| Option | Description |
|---|---|
| File | Type the file path or click the ellipsis ( ) to select your plugin file. A fully functional template (VB_RadarSrchTrkConstraint.vbs) is provided for your use. All STK inputs to the script and the output from the script are already programmed in the template. A simple data model is programmed as an example. You can replace the template example model with your own model equations. The radar-target geometry data and VGT data is independent of the radar's operational mode and is supplied to the Search/Track plugin script. |
| Min/Max | If the constraint data needs to limit the access visibility intervals, enter the appropriate minimum and/or maximum values. |
| Exclude Time Intervals | When you select this check box, STK excludes the time intervals during which the constraint is satisfied. |