Abstract: This method for the non-linear estimation of no more than two mixed signals from separate sources, the time/frequency representation of which shows an unknown non-zero proportion of zero components, using an array made up of P>2 antennas, when the directional vectors U and V of the sources emitting these signals are additionally known or estimated, includes the following steps: a) Calculating the successive discrete Fourier transforms of the signal received by the antennas and sampled to obtain a time-frequency P-vector grid of the signal; each element of the grid being referred to as a box and containing a complex vector X forming a measurement; b) For each box, calculating the conditional expectation estimator of the signal, or of the signals, from the measurement X and an a priori probability density for the signals that is a Gaussian mixture.

Abstract: A method for managing track crossovers and a device for tracking mobile objects that is suitable for implementing the method are provided. The method for managing track crossovers comprises, for each track at a given time, a step Stp1 of testing in order to determine whether the track in question is ambiguous or not at the given time and, if the track is ambiguous, a step Stp2 of specific processing of the estimate of the track.

Abstract: A method for detecting targets, implemented by a multifunction radar wherein the radar comprises an antenna subdivided into at least two portions and is configured to transmit at least two types of signals on distinct frequency bands and to perform at least one ground detection or imaging function. During the transmission phases of an antenna portion, the reception of each antenna portion of the radar is cut. The method comprises, for each range gate, a step of reception of signals, a step of estimation of the autocorrelation matrix associated with the interferences the ground returns and from the thermal noise of the radar and a step of target detection using a test of the generalized maximum likelihood. A multifunction radar configured to implement the method for detecting targets is provided.

Abstract: A passive detection method implemented by a device comprising one or more sensors comprises a step of sampling signals received by each sensor using various sub-Nyquist sampling frequency values, a step of transforming the sampled signals to the frequency domain by discrete Fourier transform, the frequency pitch ?F being chosen constant, and, for each time/frequency box, a step of calculating the normalized power in each reception channel, a step of calculating the quadratic sum of the calculated powers while taking into account the power of a possible parasitic signal, and a thresholding step carried out so as to ensure a given probability of false alarm.

Abstract: This method for the non-linear estimation of no more than two mixed signals from separate sources, the time/frequency representation of which shows an unknown non-zero proportion of zero components, using an array made up of P>2 antennas, when the directional vectors U and V of the sources emitting these signals are additionally known or estimated, includes the following steps: a) Calculating the successive discrete Fourier transforms of the signal received by the antennas and sampled to obtain a time-frequency P-vector grid of the signal; each element of the grid being referred to as a box and containing a complex vector X forming a measurement; b) For each box, calculating the conditional expectation estimator of the signal, or of the signals, from the measurement X and an a priori probability density for the signals that is a Gaussian mixture.

Abstract: A method for detecting an electromagnetic signal by an antenna array with pattern diversity and a device for implementing this method is provided. The method according to the invention requires no prior knowledge of the type of signal and can be implanted on an antenna array with pattern diversity.

Abstract: A method for managing track crossovers and a device for tracking mobile objects that is suitable for implementing the method are provided. The method for managing track crossovers comprises, for each track at a given time, a step Stp1 of testing in order to determine whether the track in question is ambiguous or not at the given time and, if the track is ambiguous, a step Stp2 of specific processing of the estimate of the track.

Abstract: A method for detecting an electromagnetic signal comprises: applying to the received electromagnetic signal a plurality of time-frequency transforms, for each time/frequency cell of a given set of cells, calculating the energy of the vector made up of the spectra over all of the antenna elements, applying the following nonlinear function T to the result of the energy calculation: if the norm of the energy is below a first predetermined threshold s, the result of the function T is zero, if the norm of the energy is above or equal to the first threshold s, the result of the function T is equal to the norm of the energy minus the value of the first threshold s, integrating, over the set of time/frequency cells, the result of the nonlinear function T, comparing the result of the integration to a second predetermined threshold, to detect the presence of the signal.

Abstract: A passive detection method implemented by a device comprising one or more sensors comprises a step of sampling signals received by each sensor using various sub-Nyquist sampling frequency values, a step of transforming the sampled signals to the frequency domain by discrete Fourier transform, the frequency pitch ?F being chosen constant, and, for each time/frequency box, a step of calculating the normalized power in each reception channel, a step of calculating the quadratic sum of the calculated powers while taking into account the power of a possible parasitic signal, and a thresholding step carried out so as to ensure a given probability of false alarm.

Abstract: A method for detecting targets, implemented by a multifunction radar wherein the radar comprises an antenna subdivided into at least two portions and is configured to transmit at least two types of signals on distinct frequency bands and to perform at least one ground detection or imaging function. During the transmission phases of an antenna portion, the reception of each antenna portion of the radar is cut. The method comprises, for each range gate, a step of reception of signals, a step of estimation of the autocorrelation matrix associated with the interferences the ground returns and from the thermal noise of the radar and a step of target detection using a test of the generalized maximum likelihood. A multifunction radar configured to implement the method for detecting targets is provided.

Abstract: A method for detecting an electromagnetic signal comprises: applying to the received electromagnetic signal a plurality of time-frequency transforms, for each time/frequency cell of a given set of cells, calculating the energy of the vector made up of the spectra over all of the antenna elements, applying the following nonlinear function T to the result of the energy calculation: if the norm of the energy is below a first predetermined threshold s, the result of the function T is zero, if the norm of the energy is above or equal to the first threshold s, the result of the function T is equal to the norm of the energy minus the value of the first threshold s, integrating, over the set of time/frequency cells, the result of the nonlinear function T, comparing the result of the integration to a second predetermined threshold, to detect the presence of the signal.

Abstract: A method for detecting an electromagnetic signal by an antenna array with pattern diversity and a device for implementing this method is provided. The method according to the invention requires no prior knowledge of the type of signal and can be implanted on an antenna array with pattern diversity.

Abstract: The invention relates to a device for aiding the analysis of signals by using symbols-based digital modulation. The device includes a signal memory for storing a complex digital signal, representative in amplitude and phase of a captured signal, over a chosen duration, as well as a processor for searching for the properties relating to the carrier frequency of the complex signal and to its modulation. According to the invention, the processor includes a projector for calculating the components of the complex signal in a function basis, the function basis being parameterized according to an estimated tempo of the modulation, as well as a calculator, operating on these components so as to determine an estimate relating to a property of the complex signal, from among its elementary pulse shape, the string of symbols of the complex signal and its carrier.

Abstract: The invention relates to a device for aiding the analysis of signals by using symbols-based digital modulation. The device comprises a signal memory for storing a complex digital signal, representative in amplitude and phase of a captured signal, over a chosen duration, as well as processing means for searching for the properties relating to the carrier frequency of the complex signal and to its modulation. According to the invention, the processing means comprise projection means for calculating the components of the complex signal in a function basis, parametrized according to an estimated tempo of the modulation, as well as calculation means, operating on these components so as to determine an estimate relating to a property of the complex signal, from among its elementary pulse shape, the string of symbols of the complex signal and its carrier.