Radar Search/Track Constraints
The following Radar Search/Track Constraints property pages allow minimum and maximum values to be entered for several parameters and presents a variety of Doppler options:
- Search/Track. These parameters correspond to the radar's main channel. These parameters account for the polarization mismatch, if polarization is selected on the Basic Polarization page.
- ST w/Jamming. These parameters correspond to the main channel radar receiver that is under the influence of jamming. When the radar receiver polarization is set and the jammers are polarized, the search/track parameters take polarization mismatch into account. Most of these parameters are re-computed under the impact of jamming on the radar receiver main channel. For more information on the effects of jamming on constraints, see Constraints with Jamming.
- MFR ST w/Jamming. These parameters correspond to the main channel radar receiver that is under the influence of jamming. When the radar receiver polarization is set and the jammers are polarized, the search/track parameters take polarization mismatch into account. Most of these parameters are re-computed under the impact of jamming on the radar receiver main channel. For more information on the effects of jamming on constraints, see Constraints with Jamming.
- S/T OrthoPol. These parameters correspond to the radar's orthogonal polarization channel.
- S/T OrthoPolJam. These parameters correspond to the radar's orthogonal polarization channel under the threat of jamming.
See MFR Search/Track constraints for information on Multifunction Radar Search/Track Constraints and Search/Track Constraints with jamming.
The STK Radar SAR computation and constraints can be extended with the Search/Track plug-in constraint. See Search/Track User Plugin.
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 Search/Track properties page.
Minimum and Maximum Parameters
| Option | Description |
|---|---|
| Single Pulse SNR | 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. Enter Min and/or Max values. |
| Single Pulse PDet | Single pulse probability of detection. Enter maximum and/or minimum values in the range 0-1. |
| Pulses Integrated | Number of pulses integrated. Enter Min and/or Max quantity. Not available for Fixed Pulse Number integration mode. |
| Integrated SNR | Integrated signal-to-noise ratio. Enter Min and/or Max values in the selected ratio unit. Not available if operating in Goal SNR analysis mode for integration gain. |
| Integrated PDet | Integrated pulse probability of detection. Enter maximum and/or minimum values in the range 0-1. Uses the number of pulses integrated value computed by the radar according to the pulse integration mode. |
| Integration Time | The integration time for the search/track radar required to achieve the goal SNR. Enter Min and/or Max values. Available only if operating in Goal SNR analysis mode. |
| Dwell Time | The sum of the integration time and RF propagation delays. Enter Min and/or Max values. |
Doppler Options
The Search/Track page allows you to set any or all of the following Doppler constraints.
Doppler constraints
| Option | Description |
|---|---|
| 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. |
| 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. |
| 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. |
| Unambiguous Range | Pulse Doppler radars are generally ambiguous in range and/or Doppler. 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). |
| 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.
Search/Track User Plugin
The 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 | Select Min to enable the plugin constraint option and browse to the plugin script 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 | Excludes the time intervals during which the constraint is satisfied. |