Abstract: A positioning system comprises an onboard GNSS satellite receiver in a mobile element belonging to a user which estimates the position of said mobile element at various instants, a first processing module determining a consistency indicator by combining the estimated positions and data provided by secondary information sources, using a dynamic model of movement of the mobile elements to be positioned. The indicator is determined by comparing a speed, acceleration, gyration triplet derived from direction and velocity measurements taken by the mobile element, to a dynamic model of movement of an object, vehicle, person or animal to be positioned. The system comprises a consolidation module containing means storing the positions estimated at various instants, a digital filter to obtain a filtered position from the stored positions of a user, the consistency indicator calculated from filtered positions; and detection means determining from the consistency indicator whether the estimated positions are falsified.

Abstract: A positioning system comprises at least one onboard GNSS satellite receiver in a mobile element belonging to a user u, said receiver having the function of estimating the position Xu of said mobile element at various instants, a processing module determining a consistency indicator coh(X) by analysis of the signals received by the GNSS receiver, said indicator being representative of the difference between the visibility of the satellites used for the estimation of position Xu[t] by the receiver and the expected visibility at this position.

Abstract: A positioning system comprises an onboard GNSS satellite receiver in a mobile element belonging to a user which estimates the position of said mobile element at various instants, a first processing module determining a consistency indicator by combining the estimated positions and data provided by secondary information sources, using a dynamic model of movement of the mobile elements to be positioned. The indicator is determined by comparing a speed, acceleration, gyration triplet derived from direction and velocity measurements taken by the mobile element, to a dynamic model of movement of an object, vehicle, person or animal to be positioned. The system comprises a consolidation module containing means storing the positions estimated at various instants, a digital filter to obtain a filtered position from the stored positions of a user, the consistency indicator calculated from filtered positions; and detection means determining from the consistency indicator whether the estimated positions are falsified.

Abstract: A satellite telecommunications system comprises at least one satellite receiving signals originating from a plurality of transmitters present in a surveillance zone called a task, the transmission of the signals by the transmitters being discontinuous and organized into time slots. The satellite includes an array of reception antennas, a set of digital reception filters being associated with each antenna. The satellite also includes means for separating the signals originating from various transmitters and colliding in one and the same slot, said separation being carried out by adapting the coefficients of the digital reception filters, said coefficients being deduced from predictions of the position of the transmitters.

Abstract: A satellite telecommunications system comprises at least one satellite receiving signals originating from a plurality of transmitters present in a surveillance zone called a task, the transmission of the signals by the transmitters being discontinuous and organized into time slots. The satellite includes an array of reception antennas, a set of digital reception filters being associated with each antenna. The satellite also includes means for separating the signals originating from various transmitters and colliding in one and the same slot, said separation being carried out by adapting the coefficients of the digital reception filters, said coefficients being deduced from predictions of the position of the transmitters.