TV signals used to track aircraft as alternative to radar

esearch carried out by the air traffic control provider Nats and its partners suggests that existing TV signals could be used to track aircraft, providing a cheaper alternative to radar.

TV signals use different parts of the radio spectrum to radar, but both bounce off solid objects.
Using special receivers, researchers said they were able to track up to 30 planes simultaneously flying at altitudes of up to 10,000ft (3km).
But they say more work has to be done.
"Questions around resilience and service standards need to be answered and we'd need to explore formal agreements with the broadcasters, but this is very exciting and we'll be looking to further develop the concept over the next five years," said Nats engineer Nick Young.

Interference resistant

The study involved a TV signal broadcast by a transmitter at Crystal Palace in London.
Three specialist receivers were used to measure the directions of the signals that reflected off the aircraft and the differences in time they took to be received compared to the rest of the unimpeded TV signal.
This "triangulated" information was then used to deduce the various planes' locations.                                                          esearch carried out by the air traffic control provider Nats and its partners suggests that existing TV signals could be used to track aircraft, providing a cheaper alternative to radar.
TV signals use different parts of the radio spectrum to radar, but both bounce off solid objects.
Using special receivers, researchers said they were able to track up to 30 planes simultaneously flying at altitudes of up to 10,000ft (3km).
But they say more work has to be done.
"Questions around resilience and service standards need to be answered and we'd need to explore formal agreements with the broadcasters, but this is very exciting and we'll be looking to further develop the concept over the next five years," said Nats engineer Nick Young.

Interference resistant

The study involved a TV signal broadcast by a transmitter at Crystal Palace in London.
Three specialist receivers were used to measure the directions of the signals that reflected off the aircraft and the differences in time they took to be received compared to the rest of the unimpeded TV signal.
This "triangulated" information was then used to deduce the various planes' locations.