Abstract: A signal processing method performs operations of coherent processing making it possible notably to purge the useful signal of the spurious signals (in particular the reference signal and its multiple reflections), to regenerate the transmission signal and to perform a coherent integration of the signal received by computing the cross-ambiguity between the signal received and the regenerated transmission signal. It also performs operations of non-coherent processing making it possible in particular to carry out extraction and Doppler distance purification operations making it possible to form blips and to eliminate the spurious blips present among the blips formed. The method applies notably to passive radars operating on non-cooperating opportunity transmissions, such as FM transmissions intended for the public.

Abstract: The present invention relates to the field of passive radars, and more particularly the field of the processing of the signals utilized by such radars. The signal processing method received according to one or more embodiments of the invention performs coherent processing, in order to purge spurious signals from the useful signal, including the reference signal and its multiple reflections, to regenerate the transmission signal and to perform a coherent integration of the signal received, by computing the cross-ambiguity between the signal received and the regenerated transmission signal. One or more embodiments of the invention also performs operations of non-coherent processing making it possible in particular to carry out extraction and Doppler distance purification operations making it possible to form blips and to eliminate the spurious blips present among the blips formed.

Abstract: A radar including a plurality of antenna arrays (B, . . . , J), for example linear arrays, the reception of electromagnetic waves being coherent for each antenna element in each array. The extraction of target signals from sidelobe signals according to the invention is obtained by comparing the signals received by the various arrays. A statistical processing allows to eliminate the responses corresponding to the array sidelobes. The invention is mainly applicable to radars including a plurality of linear lacunary antenna arrays with an isotropic disposition in space.

Abstract: Disclosed is a method for the adjusting of the detection threshold of a radar receiver for a distance zone called a search zone surrounded by distance zones called adjacent zones, fitted out with a module enabling the computation of the mean value as a function of the distance of the ambient noise along an axis starting from the receiver wherein, for each search distance zone, the detection threshold is raised by a zero value when the ambient noise is low and by a value that increases monotonically with the level of the noise measured when the ambient noise is greater than a pre-determined threshold.

Abstract: A device and a method for the transmission or storage of data optimizing the use of the pass-band. Also, a method for transmission by phase modulation. In order to obtain high data throughput rates, the synchronization of a transmission clock with the reception clocks is used. This synchronization is gotten, for example, by transmission of a pseudo-random code and by the convolution or correlation of the received signals with the pseudo-random code. The invention also enables the elimination of multiple echoes by computation. The invention can be applied chiefly to the transmission of radio programs, television broadcasts or digital data.

Abstract: To make an "intelligent" selection, in a radar, of the piece of information transmitted to the tracking unit by the extractor, in case of saturation, a method comprising the first step of selecting a set of N attributes (x.sub.1, x.sub.2, . . . x.sub.N) defining the plots given by the extractor. Then quantifying each attribute, in defining intervals in the range of values taken by the attribute and associating, with each N-tuple formed by a combination of values of the attributes, an estimated value of validity of the corresponding plot. Further, for each plot transmitted by the extractor, searching for the N-tuple that corresponds to it, in order to associate the estimated value of validity, assigned to the N-tuple, with the plot.