Air Traffic Control 
MLAT ADS-B RTX System 

ADS-B and WAM multilateration systems for air traffic control

SICE designs and builds a complete line of air traffic control (ATC) sensors based on ADS-B and Multilateration. They are an integral part of the monitoring systems of airports and their immediate surroundings but also of the monitoring systems over geographically large areas (wide area).

SICE sensors, easily positioned in both indoor and outdoor installations, are designed to process standard ICAO ac/S/S Extended Mode signals and are therefore able to interoperate with avionics transponders on board commercial aircraft. All sensors have a TCP/IP communication interface for interfacing with a Control Center, for traffic management and for the configuration, alarming and remote monitoring of the sensors themselves.

SICE supplies four basic types of sensors suitable for fixed installations on the ground: receivers, transmitters, transceivers and power amplifiers to expand the range of coverage of the transmitters. Depending on the needs, the sensors can be combined in various ways: many configurations are available and the system is extremely flexible. In addition to the four basic types of fixed devices, there is also a special mobile device to be placed on the roof of the service vehicles at the airport; this latter device, called Vehicular Mobile Transponder, is able both to transmit the position of the vehicle to the air traffic control network, and to provide the driver of the vehicle with a map showing the position of the aircraft manoeuvring in the vicinity of the vehicle itself. All fixed sensors (transmitters, receivers, transceivers) are manageable via TCP/IP network and are designed to build a real network of surveillance and control nodes. The ease of installation, the high scalability of the system, the dual technology of position calculation (ADS-B and Multilateration), the high sensitivity of the receivers and the power of transmitters make the ATC system built with SICE sensors highly reliable and easily scalable and redundant.

The sensors are based on ICAO Mode AC/S/S Extended signals. In particular, the receivers not only decode the messages received from the transponders but are also able to mark them temporally (with accuracy of the order of a tenth of a nanosecond) in order to make it possible not only to estimate the position of the aircraft through the declared GPS position but also to calculate the position itself with multilateration algorithms. The receivers, thanks to their very wide dynamic range (80 dB) and their high sensitivity (-95 dBm) are able to monitor areas up to 200 nautical miles. Transmitters, on the other hand, can be used to selectively query transponders. The maximum transmission power, thanks to the High Power Amplifier module, reaches 3KW impulsive. The receivers communicate the received data to the Control Center via TCP/IP network. Thanks to the decoder entirely developed in hardware, the maximum achievable throughput is very high and allows to process several thousand messages per second, ensuring the effectiveness of the system even in the most demanding scenarios. GPS is integrated into the system and allows to keep the sensors constantly synchronized; however, in contexts where it is not possible to use GPS for synchronization, there is an alternative mechanism that still allows the use of sensors.

In addition, thanks to the vehicle device, the position of mobile service vehicles can be monitored in real time directly in the traffic control system. Not only that: the vehicle device also has a receiver capable of sending to a tablet the entire vehicle the map of the airport with the location of the aircraft and service vehicles nearby. A peculiarity of the vehicle device is that it can transmit its position even when the GPS signal is absent for short distances.

SICE completes its portfolio of MLAT, ADS-B sensors with a range of radio links that allow to build complete networks for air traffic control even in areas where it is difficult to create wired networks. Such devices are especially useful when you want to build a large area ATC network (WAM).