Process and system for determining the position and orientation of a vehicle, and applications

Process for determining the position and orientation of a vehicle, comprising the steps of:

• transmitting, from a radar containing two channels for reception and for processing, an interrogation signal with a given frequency f;
• retransmitting, from said vehicle, at least two response signals formed by modulating said interrogation signal received by the vehicle respectively by a modulating frequency F.sub.1 and by a modulating frequency F.sub.2 which differs from F.sub.1, the two response signals being retransmitted according to two respective transmission patterns D.sub.1 and D.sub.2 which differ in aim relative to one another by an angle .alpha., and each relative to the direction of orientation YY' of the vehicle by an angle .gamma..sub.1 and .gamma..sub.2 respectively, at least two of the three angles .alpha., .gamma..sub.1 and .gamma..sub.2 being supplied to the radar;
• measuring, from the reception channels, the angular deviation of either of the two response signals and deducing therefrom the angular position .phi. of the vehicle relative to the radar;
• measuring the ratio of the amplitudes of the two response signals received on one of the reception channels;
• deducing therefrom, based on the angles supplied and on the shape of the patterns D.sub.1 and D.sub.2, the orientation e of the vehicle relative to the radar.