The Thomson Adour mobile trajectory radar, a tool used to show exactly where an aircraft is flying, is being used to make sure pilots remain in their designated areas during this year's Paris Air Show.
The system, known as Sampam, uses a high sampling rate to make sure that aircraft are tracked over every second of flight, displaying warnings to pilots when they are in danger of entering restricted airspace.
The system, which has been in place at the air show since Wednesday has been used for rehearsals and will also, be used in real time during the show.
The permitted area around Le Bourget Airport, where the show is being held, is very strict due to multiple fly zones, strict boundaries with Charles de Gaulle Airport and a 500ft limit over the town of Dugny to the south-west.
Theoretically, the radar could be used to halt a show and even penalise exhibitors if they infringe on the rules.