Objectives
Radar Monitoring and Evaluation Environment (RadarWatch) is an essential analysis environment that supports on-going radar maintenance by detecting radar malfunctions, and providing a comprehensive radar performance analysis. RadarWatch has two modes of operation:
• On-Line Mode - monitors and detects malfunctions in the radar reports caused by the radar or by the communication
• Analysis Mode of Operation - this tool further analyzes the collected data, and computes figure of merits reflecting radar performance and availability.
Scope
Radar-Watch evaluates the following categories of radar:
• Radar reporting plots: SSR, Primary and combined plots
• Mono-radar tracks
On-Line Mode of Operation
In the On-line mode of operation, the Radar Watch collects the radar data in a sliding time window, performs a variety of statistical analysis, and further analyzes the data to detect malfunctions or deviations from "standard" behavior. The various results are grouped according to the cause of the problem, i.e.: radar, communications, radar, and/or communications. For various malfunction reports, the operator can set alarm thresholds, thus when such a threshold is exceeded, a corresponding alarm is generated.
Statistics Presenting Malfunctions Caused by the Radar
Deviations from expected, or missing Angle Message reports, provide a sound indication on radar problems. The following are analyzed (per radar):
• Angle messages rejection occurrences (with reasons, such as 'too early', 'too late', wrong value)
• Distribution of azimuth of missing angle messages
• Distribution of azimuth of rejected and accepted angle messages
Statistics Presenting Malfunctions Due to the Communication with the Radar
An irregularity in the received Frames provides an indication of a communication problem with the radar. The following are analyzed:
• Frame rejection occurrence statistics, presented in histograms versus rejection reasons (such as address, CAC) for all plots (PSR plots, SSR plots, and combined plots).
• Error rate graphs versus time. Error rate is a ratio of the number of corrupted frames to the number of received frames, within a user specified time interval.
Statistics Presenting Malfunctions Due to Communications or Radar
The following irregularities indicate on malfunction of the communications with the radar, or malfunction of the radar. The following are analyzed:
• Plot quantity diagram for different plot types. This analysis can be performed when the radar reports both PSR and SSR plots, or, more than one radar is connected.
• Plot time delay distributions for different plot types.
Analysis Mode of Operation
In this mode of operation, Radar Watch analyzes the radar collected data, and calculates the overall radar performance figures of merit for various radars. Also, all the statistics calculated in the On-Line mode, are available in this mode as well. For each radar, the following performance figures of merit are calculated:
• Pd (Probability of detection):
• The estimation of total radar Pd as well as the Pd in different radar sectors is calculated. An indication is given when the calculated Pd values, are lower then expected.
Pfa (False plots rate) - the estimation of radar Pfa is calculated. An indication is given when the calculated Pfa value is higher then expected.
• Radar measurement errors - the estimation of total radar measurement errors (in Range, Azimuth and Elevation) as well as radar errors in different radar sectors.]
• For each Radar, it also calculates the following:
o Radar Coverage
o Rectified radar clutter map
• For all the radars, Radar-Watch calculates the following combined analysis:
o Multi radar combined coverage
o Multi radar combined update rate
Configuration and Components
Radar-Watch may be configured in one of the following:
On-Line Configuration
In this configuration, Radar Watch supports the capabilities described in the On-Line Mode of Operations. Radar-Watch is connected to the radars via the SLI component.
Analysis Mode Configuration
In this configuration, Radar Watch supports the capabilities described in the Analysis Mode of Operation. The radar’s data should be supplied on a DAT.
Full Capabilities Configuration
The system provides both the On-Line Mode capabilities and the Analysis Mode capabilities.
Components
The following components are used:
• Operator Work Stations (OWS) including DAT. Several OWS might be connected, if required.
• Radar Interface (SLI)
• Printer(s)
• Communications infrastructure (LAN)
• The OWS and SLI components, are used in the following configurations:
Supported Radar Protocols
Radar Watch supports the following communication protocols:
• HDLC
• Bisync
• Common Digitizer
• The following radar messages are included:
• ASTERIX
• AIRCAT
Other formats are available as needed.