Abstract: A method for the detection of M0 sources common to several observations u(t) and v(t) within a single array of sensors, the observations having different lengths N1 and N2, comprises at least the following steps: defining a law of likelihood Vuv([M=M0]/M0) substantially equal to the chi-2 law with 2(N1−M0)(N2−M0) degrees of freedom with N1≦N2, dim{u(t)}=N1×1 and dim{v(t)}=N2×1; determining a detection threshold &agr;M in order to obtain a low probability of false alarms and a number of degrees of freedom that takes account of the lengths N1 and N2 and of the number of sources M0; determining the presence and/or the number of the sources M0 in applying the law of likelihood and the threshold &agr;M. The method and device can be applied to the determining of the presence and/or the number of sources common to at least two observations having different lengths in a GSM type radiocommunications system.

Abstract: The invention relates to a process for locating radio sources by means of a two-channel high resolution radiogoniometer comprising a network of a specified number N of sensors (21 . . . 2N).

Abstract: Method and device to carry out space-time estimation of several transmitters in an antenna network, consisting of determining the various arrival angles &thgr;mi of the multipaths pm transmitted by each transmitter.

Abstract: The disclosure relates to a process of cyclic detection in diversity of polarization of digital cyclostationary radioelectric signals. The process consists in acquiring the signals on a network of at least two of antennas, in calculating a cyclic covariance matrix on a first moment, and on a second moment, of a spectral correlation of the digital signals acquired, and in detecting peaks of spectral correlation by comparing a likelihood ratio with a detection threshold determined statistically. The invention is applicable notably to digital radioelectric signals emitted by a satellite.