The dramatic advances in information and communication technology, electro- optical technologies and digitalisation have enabled a revolution to take place in terms of airport air (and ground) traffic control. This was highlighted in a briefing at the recent Africa Aerospace and Defence 2018 exhibition by Saab VP: civil security (Middle East and North Africa region) David Shomar. Saab has played a leading – in some cases the leading – role in these developments. He pointed out that remotely controlled digital air traffic control (ATC) was now operational in Sweden, the Republic of Ireland and in the state of Virginia in the US.

Saab’s digital ATC system involves the use of high-resolution cameras, microphones, digital imagery systems, large high-definition screens, secure digital telecommunications and the necessary operating software system. This results in enhanced tools for the controllers rather than the traditional method of having air traffic controllers seated in a control tower and looking out of the windows, using binoculars. The system allows the control room to be located away from the airport. No fewer than 14 high-resolution cameras are mounted in a 360º array on top of a tower, giving all-round coverage of the airport and its air approaches.

In addition, above these is mounted a high-resolution zoom camera (known as the PTZ camera). This serves both to provide backup in case one of the 14 fixed cameras fails, and to allow the controllers to zoom in on a specific location or event. Conventionally, they would have to use binoculars for this, but the PTZ camera provides not only the same or better magnification but also a wider field of view than would be possible with binoculars, allowing the controllers to keep observing their controlled airspace while zooming in on a particular location.

The imagery from the digital cameras is displayed on 14 screens in the control room, called the Out the Window Display, arranged in a continuous 360º ring around the controllers, who thus have a seamless all-round view of the airport. The system includes two microphones, which allow them to also hear what is going on, thereby enhancing their vision of the controlled environment.

Because of the capabilities of digital technology, controllers can eliminate rain from the displayed images, so downpours will not affect their vision. It also allows the effects of fog to be greatly reduced. Other very useful attributes of the system include the ability to adjust automatically for different brightness levels and to filter out direct sunlight. Even without infrared capability, the high- definition digital cameras capture the ambient light to allow a good amount of visibility at night. (The advantage of infrared capability is that it can track flying aircraft and not just aircraft on the ground.)

The system also allows the visual tracking of aircraft and the display, alongside the aircraft on the screen, of flight and aircraft data. In conventional ATC systems, the controller would have to switch his or her attention from looking at the aircraft through the window to looking at its information displayed on a computer screen. The system automatically detects and tracks anything flying within its range. It has been discovered that the resolution of the digital cameras is so high that even small drones are detected and highlighted by the system.

The digital technology also allows full flight and control data fusion, allowing controllers to have all the information they need on all flights on only two or three screens.