Hear in my car

ESA and its partners have demonstrated a multimedia car radio at the Noordwijk Space Expo in the Netherlands which could eliminate crackling stations, signal loss in tunnels and tuning difficulties.

The car radio works like a television satellite receiver, but instead of a dish antenna, it uses a specially designed mobile antenna, flattened so that it can be built almost invisibly into the bodywork. The antenna receives signals in the Ku frequency band used by communications satellites.

The idea of an in-car satellite receiver is not new. In America, more than 13 million people use the services of broadcasters that transmit to mobile satellite receivers via communication satellites and with the help of a rural network of transmitter masts.

Instead of new satellites and a network of ground-based transmitters, which might easily cost more than €1bn, the ESA system uses only existing communication satellites.

The mobile multimedia system employs a cache memory, either a hard disk or its solid-state equivalent, to store received signals in a similar way to personal video recorders, to be played back after a short time shift or much later. This intermediate step prevents loss of signal in tunnels or behind obstructions from disturbing the programme. The listener can also select a part of the broadcast to listen to, or pause the broadcast if they break their journey.