Radar systems studied at INRETS to the road and railway fields

Obstacle detection by radar can apply as much to road transport as to public transport. Such systems are studied by the INRETS-LEOST within the framework of the Regional Group for Transportation Research. Most of the microwave sensors were carried out by the IEMN-DHS. They were founded either on a linear frequency modulation (FM/CW) or on a pulse modulation. These studies led to a dual-mode radar, coupling the advantages of the two systems, but nevertheless expensive. Then, with the help of the IEMN-DOAE, we studied a radar sensor using the correlation of pseudo-random binary sequences. This model, initially intended for the road field, was adapted to a public subway transport. Since a traditional radar cannot function because of the multipath effect in the tunnel, our system uses a cooperative mode, i.e. it recognizes the preceding train, calculates its distance, and also evaluates its state of operation. This system, combined to simple responders, also leads to road applications, for the detection of particular fixed obstacles, like piles or road panels, which are difficult to filter on the current radar systems, because of the significant energy that they return towards the sensor.