Yeah it's vehicle recognition. It sees your car, remembers what it looks like, then picks it again at the next camera. It works out your average speed between the 2 points based on how far they are apart and how long it took you to get there, and books you if you exceeded the limit.
That being said, if it takes you 20 minutes to travel between them at the speed limit, you could stop for 10 minutes after passing the first one, then double the speed limit (160km/h in this case) the whole way there, and not get booked by this system.