• SSR and PE primary radar data fusion.
• Primary video data fusion.
• Minimum safe altitude warning (MSAW).
• Short term conflict alert processing (STCA).
• Radar and display environment recording.
• Arrival and departure notification.
• Controller training and simulation using the Micronav BEST system.

A dedicated processor is used to provide the short term conflict alert processing, and together with MSAW, is currently being rolled out to all NATS airport ATC units.

The key aspects of this are:

The units control zone is divided into discrete regions, each defined as a polygon with an upper and lower height boundary. Within each region the parameters used to determine a potential conflict alert are configurable, including on/off, vertical only, lateral only or vertical and lateral combined. This is essential to reduce the number of false alarms, for example in a stack. Conflict alert processing is applied to each radar sweep, so targets that move out of conflict are automatically cancelled.

There is no limit to the number of MSAW and STCA regions that may be defined.

On detection of new STCA Colour Change (configurable) Special SPI ON Vectors ON (special line style) SPI only flashing Audio alarm ON	After Controller presses ALARM ACK Flashing stops Audio alarm stops Alarm colour remains until conflict is cleared	Normal Presentation Once STCA conditions are cleared

The Geographical Region Processing may be used to detect aircraft straying outside the climb-out noise control corridors. Regions are defined on either side of the corridors. Any return detected below a specified altitude in any of the polygons flashes to alert the controller to the incursion. By designating the regions as sensitive to ascending aircraft only, only departing aircraft will trigger a warning. The time, aircraft code, callsign, altitude, height trend and position are transmitted over the network to the System Control Position, where they are logged and may be feed into a noise pollution zone monitoring system, this may be deployed remotely in the local environmental health department (as at Farnborough) The data collected can also be correlated with readings from the noise monitoring stations.

Data fusion of Primary Radar video channels and SSR data channels are kept separate until the point of display. The processing is described below:

The primary video data fusion processor enables radar data from numerous primary radars, to be integrated into a single radar display. The system enables seamless coverage of very large geographic areas and employs the same input processing and co-ordinate conversion algorithms as the radar displays. The output data stream is also structured to mimic a single radar providing the combined coverage. The Primary Data Fusion Processor connects to the radar servers task at multiple locations. Data from each Server is read into an input store that contains the corrected geographical positions for all the range azimuth cells of each channel. When a display position calls for a composite picture, its range and offset are used to create the boundaries of an output store. The output store reads all the range and azimuth cells (from the array of radars) that are relevant. A diagram showing a single channel system is presented below:

The output store may be configured to display each radar in a number of ways:

As simple overlapped coverage, which is commonly used in SMR applications. With each radar channel displayed in a unique polygon that optimises the transition boundary between different radars. This is commonly used in Area Radar Control applications, or to fill in blind spots such as in the radar overhead.

The processor then sweeps through the output store and the data is routed to the display positions. A typical fused primary presentation is shown below:

The SSR data fusion processor radar data from numerous secondary radar, plot extracted primary radar or GPS data sources to be integrated into a single plot/track database. The system enables seamless coverage of very large geographic areas and employs the same input processing and co-ordinate conversion algorithms as the radar displays. The output data stream is structured to mimic a single radar providing the combined coverage.

The criteria for combining multiple plot or track reports from different data sources are:

• Code Match
• Horizontal Proximity
• Vertical Proximity (where available)
• Speed
• Heading

The Data Recording System provides three categories of recording:

• A complete history of the display screen settings and all operator inputs.
• All PE, SSR and ADS target messages.
• All Analogue primary foreground channels.

The recording can use spare channels on the airports voice recorder to ensure synchronisation with communications or its internal hard disc as the bulk storage medium. Long term copies are made on DVD, CD or DAT tape media. Recorded Data may be replayed at any display position, and as a safety precaution a flashing "R" is displayed in the top left hand side of the display screen during replay.

The RDS-1600 has a track monitoring capability. This was designed to output aircraft positional data to a Noise Track Monitoring System, but the output data stream could be used by, for example, a FIDS. Three-dimensional detection regions can be configured, and the RDS-1600 will output a unique message each time an aircraft is detected by the SSR within any region.

The diagram below illustrates a possible configuration of the Arrival and Departure detection regions (depending on Runway in use)

The Detection regions are normally configured to achieve two SSR interrogations of the aircraft as it passes through a detection region. This function is provided by the SMP, which also logs MSAW violations, Noise track violations and STCA statistics.