Radar monitors runways for debris at ground level

A new radar system could increase airport safety by monitoring runways for debris at ground level.

Researchers in Germany have developed a weatherproof system comprising an infrared camera, optical 2D and 3D cameras and networked radar sensors that can detect non-metallic, as well as metallic objects — a problem with previous systems.

The scanners are also mounted along the runway instead of high up on masts where they could easily be damaged in the event of an aircraft accident.

‘Our technology would have prevented the Concorde tragedy from happening,’ said Dr Helmut Essen of the Fraunhofer Institute for High Frequency Physics and Radar Techniques, one of the centres working on the technology.

‘[The devices] can detect even the smallest of items, such as screws, but the system will only issue a warning if an object remains on the runway for a longer period of time. A windblown plastic bag or a bird resting briefly will not set off the alarm.’

A Concorde aircraft crashed during take-off in 2000 after one of its tyres burst as it rolled over a piece of metal lying on the runway and sent chunks of rubber flying into the fuel tank, which then exploded — causing the loss of 113 lives.

To avoid similar accidents, airport staff drive up and down runways at six-hour intervals looking for any pieces of debris. But this is time-consuming and prone to errors, especially in bad weather.

The new system uses radar to function around the clock and whatever the weather. It can detect objects but not identify them. The cameras are better suited to classifying objects, but they are affected by the weather and the time of day.

The radar sensor can detect objects just centimetres across on runways

‘Our radar sensor transmits at a frequency of 200GHz, so it can detect objects that are just one or two centimetres across,’ said Essen.

‘And using three different kinds of sensor means false alarms are almost out of the question. The device is miniaturised and scans up to 700 metres in all directions.’

Whenever a radar sensor detects something, it instructs the cameras to take a closer look. All the sensor data is then amalgamated using software to produce a situational overview.

If the overview shows an abnormal situation, air-traffic control is informed in the tower. They can take a look at their screens to judge whether there is a real danger and, if so, halt air traffic.

‘Our solution is merely an assistance system. The final decision on how to proceed lies with airport staff,’ said Dr Wolfgang Koch of the Fraunhofer Institute for Communication, Information Processing and Ergonomics, a partner on the project.

Initial testing of a radar sensor and camera will begin at Cologne-Bonn airport this autumn and plans are in place for further testing using several demonstrator systems before the project ends in April 2012.