Abstract: Acoustic distance measuring apparatus for measuring the distance of a vessel (N) from a vertical line through a fixed point (P) on the bottom of a body of water, the apparatus comprising: an acoustic emitter unit (I) and at least three acoustic receiver units (H1, H2, H3) disposed on the bottom of the vessel, said receiver units being disposed at the vertices of a plane polygon; at least three acoustic emitter/receiver units (A, B, C) placed on the water bottom in the vicinity of said fixed point (P), said emitter/receiver units being disposed at the vertices of a polygon; and the improvement wherein the measuring apparatus further includes a relay acoustic emitter/receiver (R) submerged close to the vessel at a depth where vessel noise is highly attenuated, said relay receiing acoustic waves (a) from the vessel's emitter and responding by emitting acoustic wave (1, 2, 3) to the vessel's receiver units thereby enabling the distances between the relay and each of the vessel's receiver units to be calculated, s

Abstract: A transmission system is provided with a transmitter (10) transmitting data in series, either individually or in groups, by phase shifts applied to a transmitter carrier between characteristic instants which are separated by equal time intervals. The system further comprises a receiver (20) which is sensitive to phase shifts in the transmitter carrier between the characteristic instants. The transmitter comprises a coder (2) which causes the data to be transmitted to correspond to discrete values of a shift, and a symbol synthesizer (3) under the control of the coder to generate the waveform of the phase variation between two successive characteristic instants. This waveform is continuous and has minimum gradient and can be expressed as a function of time by a polynomial law. The receiver uses a synchronous demodulation and a correlation method to recover the characteristic instants and also the frequency drift between the transmitter carrier and the receiver carrier.

Abstract: The subject matter of the invention is a method of substituting an electronic component (A1) for an analogous component (1) connected to the conductive tracks (3) of a support substrate (2) by connection wires (4). The conductive tracks are cut beyond, relative to the component (1) to be taken out of service, the zones where the connection wires (4) are connected to the tracks, then the replacement component (A1) is placed on the upper glued face of the component (1), and is connected to the tracks by connection wires (4A) independent from the preceding wires.This invention is particularly applicable to integrated circuits and to vacuum-deposited resistive thin film circuits.

Abstract: A feed-through (2) is in the form of a generally cylindrical pin extending through the thickness of the wall of the box (1). Its end projecting outside the box is terminated by a generally cylindrical head portion (23) of greater outside diameter than the rest of the pin, said head portion is fixed at a distance from the wall of the box and is provided with an axial bore (24) suitable both for receiving a contact of an external connector and for receiving a conductor lead to be soldered thereto, depending on the requirements of a user.

Abstract: A sonar system comprises a vehicle (1) capable of moving over the bottom of an extent of water, with an emitter of acoustic pulses and a receiver of acoustic energy mounted on said vehicle. Signal processing and display circuitry (e.g. on board a surface vessel 2) are connected to receive signals representative of the acoustic waves emitted by the emitter, of the acoustic waves received by the receiver, and of parameters describing the motion of the vehicle. The signal processing and display circuitry generates an image of objects hidden in the water bottom on the basis of the signals. The emitter of acoustic pulses is provided with at least one parametric transducer having a spot radiation pattern capable of forming a plurality of channels that bathe spots of the water bottom in sound waves, and an electronic pointing system for scanning the channels.