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MATS operates three radar sites – at Luqa, Dingli and Hal Far. A fourth one is currently under construction at Fawwara. The Luqa and Dingli installations both comprise a primary and a comounted secondary radar, with the Luqa system giving a terminal approach radar service and the Dingli system an enroute radar service. Hal Far and Fawwara will each host a secondary radar that can contribute toward approach and also enroute service.

By far, radar is the most complex and important tool that the ATC makes use of. The system can usually be best described as a radar chain. The first link in this chain is the radar head (or radar sensors), consisting of antennae, microwave transmitters and receivers. In the Luqa and Dingli cases, each radar head is made of a redundant and duplicated system of Primary Surveillance Radars and Secondary Surveillance Radars.

A primary radar emits a strong pulse and any target in the region covered by the radar sends back a weak echo giving the azimuth and range of the target. Since any object can generate this echo, a primary radar is termed non-cooperative, and it is up to the system processors to filter out non-relevant targets.

A secondary radar is a cooperative system in that the transponder on the aircraft must be switched on to respond to an interrogation from the radar. The data sent back is interpreted by the radar receiver, and includes position, altitude and the assigned code. Mode S radars at Hal Far and Fawwara would allow for interrogation of the aircraft individually, given that each airframe would have a unique address.

All the data is transmitted to the operating centre at Luqa Tower. At this centre we also receive data from Ustica (Italy), Kithira (Greece), Lefkas (Greece) and there are plans to integrate other radars in the future. Multiple radar coverage is essential for modern air traffic control purposes, and it is common practice for neighbouring states to SHARE radar data to ensure coverage. Our flight information region (FIR) covers a stretch of the Mediterranean from Tunisia to Greece, without any land-based radars for most of the way. For this reason, we depend on data from radars on the land mass around the Mediterranean. Data from the various radars (each with its own rotation speed, location, instabilities, ranges, visibilities and other variables) is handled by a Multi Radar Tracker that utilises complex algorithms to give the controller a reliable (synthetic) picture of actual traffic. This requires that data be elaborated in real time and distributed to the operating consoles with an acceptable delay.

The radar chain incorporates conventional and state-of-the-art technologies ranging from mechanical clutches and gearboxes, three-phase electric motors, modems, LANs, and various operating system platforms, to electronic receivers with matched filter IF stages, hardware digital signal processors, and complex algorithms.

A separate non-cooperative surveillance system has been set up to assist controllers in having a better picture of traffic on the airfield. This system is composed of clusters of cameras that have been installed around the airfield to give a contiguous view. A radar-like tagging software is incorporated in the system that identifies the moving object, with the information easily corroborated by video images of the object.