Abstract: A radar including a plurality of reception antennas corresponding to a plurality of homodyne reception channels, and a transmission antenna positioned with respect to the plurality of reception antenna such that a distance between the transmission antenna and each consecutive reception antenna of the plurality of reception antenna respectively increases from one reception antenna to the next. Also included is a beam-formation mechanism associated with the plurality of reception channels for receiving a reception signal from each of the homodyne reception channels. Further, a spacing between each reception antenna is set so as to orient a homodyne leakage in a direction located in an angular zone of space not processed by the radar.

Abstract: Disclosed are a method and a device for the removal of ambiguity in distance. The method computes the distance of the targets detected by the radar using several estimation functions (21, 22, 23). When the estimation functions give substantially the same result, the targets are defined as being in the field of non-ambiguous distances and when the estimation functions give different results, the targets are defined as being in the domain of ambiguous distances. Application especially to frequency-shift keying, continuous-wave radar for automobile traffic control.

Abstract: Disclosed is a radar for the detection of obstacles. The radar uses at least four frequencies referenced F.sub.1, F.sub.2, F.sub.3, F.sub.4 such that:F.sub.1 -F.sub.3 =F.sub.2 -F.sub.4and such that:(F.sub.1 +F.sub.3)-(F.sub.2 +F.sub.4)=Cte where Cte represents a constant frequency value, the measurement of distance from the target being done on the basis of the difference in phase between two signals of which the first (r.sub.1 (t)-r.sub.3 (t)) is constituted by the difference between two received signals corresponding respectively to the frequencies F.sub.1 and F.sub.3 and the second (r.sub.2 (t)-r.sub.4 (t)) is constituted by the difference between two received signals corresponding respectively to the frequencies F.sub.2 and F.sub.4. Application in particular to automobile speed control.

Abstract: A method for detecting fixed or moving objects within an angular zone, as may be used in vehicle anti-collision systems, employs separate and distinct transmission and reception patterns. The transmission pattern successively illuminates consecutive segments of the angular zone. The reception pattern receives echo signals in parallel from illuminated objects in each zone segment. The echo signals are then digitally beam formed into a total field signal. The angular positions of the detected objects are then derived from the total field signal.

Abstract: Disclosed is a method for the measurement, by means of a radar, of the distance from a useful obstacle that is surrounded by parasitic obstacles but sends back an echo which is more powerful than their echos. This method of measurement can be applied to the measuring of the level of liquid in a vessel. It consists in transmitting a sequence of non-modulated microwave signals whose discrete angular frequencies are evenly distributed in a certain frequency band, demodulating the signals received in return for the transmitted signals, subjecting the received and demodulated signals to a reverse and discrete Fourier transform with a view to a coarse localization of the delay of the echo from the useful obstacle and a high resolution method for the localization of the radiating sources with a view to a more precise localization of the delay of the echo from the useful obstacle, said delay enabling the assessment of the distance from the useful obstacle to the radar. FIG. 5.

Abstract: Disclosed is a method for the discriminating of obstacles by means of a radar, and its different applications to the measurement of a liquid in a tank or vessel, or again to the elimination of unwanted or parasitic echos coming notably from the ground, for radars mounted on vehicles or controlling vehicle traffic. To implement the method, the obstacle to be discriminated must have a substantially plane surface. The disclosed method then consists in successively transmitting substantially plane waves at slightly different angular frequencies .omega..sub.i, each wave being furthermore sent with two different polarizations p and p' chosen in such a way that these different coefficients of reflection on the obstacles according to the incidence of the waves give a criterion of discrimination. The processing at reception depends on the use (measurement of distance, elimination of parasitic echos etc.).