Abstract: A precise 3D position-finding system and method comprises at least the following elements: a set of beacons working on the basis of differential global positioning satellites (DGPS), the beacons being connected to one another and temporally synchronized, spread-spectrum radio means between the members of the network whose position is to be located and said beacons, and a computation station. The computation station is provided with a processor adapted to finding the position of one or more elements from a list of direct paths and/or multiple paths with the time and direction of arrival of each of the direct paths and/or multiple paths, and from the position of the beacons and in taking account of data that represents obstacles.

Abstract: A device for non-selective identification in a communications network comprises several users, the data being exchanged in the form of frames, wherein: at least each user has a data processor responsible for the management of the voice, data and video services; a user who is a master or group leader is equipped with a radio terminal, one or more directional antennas and a processor activated in “master” mode; several users Ui are each equipped with a radio terminal, one or more directional antennas and a processor placed in “slave” mode; a data frame comprises a “non-selective” identification device comprising at least one first part reserved for interrogation by one of the users and a second part enabling users concerned by the response to respond.

Abstract: A precise 3D position-finding system and method comprises at least the following elements: a set of beacons working on the basis of differential global positioning satellites (DGPS), the beacons being connected to one another and temporally synchronized, spread-spectrum radio means between the members of the network whose position is to be located and said beacons, and a computation station. The computation station is provided with a processor adapted to finding the position of one or more elements from a list of direct paths and/or multiple paths with the time and direction of arrival of each of the direct paths and/or multiple paths, and from the position of the beacons and in taking account of data that represents obstacles.

Abstract: The disclosure relates to devices for the measurement of signals in the field of wideband phenomena. More precisely, a device is disclosed for the processing of electrical signals coming from a derivative type of sensor designed to measure an electrical or magnetic field, currents, surface charges or other derivative variables, said processing including the computation of the primitive of the part of said signal having a spectral frequency higher than a low frequency f.sub.1, the device comprising:means for the electronic integration of said signal, from a frequency f.sub.2 higher than said low frequency f.sub.1 ;compensation means amplifying and integrating said signal between the frequencies f.sub.1 and f.sub.2. FIG. 2 .

Abstract: The sensor makes it possible to increase the performances, particularly from the sensitivity and frequency band standpoints, by means of a coaxial helical coil, matched to the connecting end to an auxiliary current measuring apparatus. At each turn, a portion of the external conductor is bared and equipped with elements for matching to the characteristic impedance in order to compensate the breaks caused in this way.

Abstract: In a data-transmission system designed for operation over a very broad temperature range and having a very large dynamic range, the receiver is of the type providing an alternating-current connection between the transimpedance circuit assembly and two comparator circuits for processing a signal which is coded at three levels. A threshold-generating circuit permits automatic switching of the thresholds among a plurality of predetermined discrete values as a function of the variation in amplitude of the signal. A circuit for inhibiting overoscillations is provided prior to transcoding. The transmitter delivers the information in the form of an internal code such as a PBP code having a constant direct-current component, and with refreshment. A delay circuit prevents overlapping of the code and refreshment pulses.

Abstract: Disclosed is a device for automatically controlling the gain of a receiving channel in a system comprising optical connections having a very wide pass band.The useful signal of unknown level is transmitted with a pilot signal of known level through an optical connection, where it undergoes an attenuation, to a receiving assembly connected to an opto-electronic transducer at the output of the optical channel. A device for controlling the gain of the receiving channel commanded by the pilot signal digitally controls an attenuation circuit which thereupon restores the useful signal to its initial level.

Abstract: The correlator comprises a piezo-electric substrate on the ends of which there are arranged two transducers supplied with two electrical signals and emitting two contra-propagating surface waves. The correlator furthermore comprises m processing channels supplied with electrical signals induced by the surface waves at m "points" on the substrate which are distributed in the direction of propagation of the waves. Each channel comprises a non-linear device and an integrator furnishing a sample of the correlation function of the two signals.