Abstract: The invention relates to the field of devices intended to generate a noise of high amplitude having specific spectral characteristics. It concerns a transmission device mainly comprising a transducer, means for synthesizing a digital noise sequence x?(n) and power sources. According to the invention, the device also comprises means such that according to the value, at each time t, of the synthesized noise sequence, the transducer is supplied by one or more noise sources placed in series, the overall voltage reflecting the value of the digital noise sequence. The transition times between two supply values are synchronous with the basic clock of means which synthesize x?(n). The invention also relates to a method for iteratively synthesizing, under spectral constraint, a noise having a power spectral density corresponding to a given template. The invention applies in particular to the submarine acoustic noise generators on board small-size autonomous craft.

Abstract: The invention relates to the field of devices intended to generate a noise of high amplitude having specific spectral characteristics. It concerns a transmission device mainly comprising a transducer, means for synthesizing a digital noise sequence x?(n) and power sources. According to the invention, the device also comprises means such that according to the value, at each time t, of the synthesized noise sequence, the transducer is supplied by one or more noise sources placed in series, the overall voltage reflecting the value of the digital noise sequence. The transition times between two supply values are synchronous with the basic clock of means which synthesize x?(n). The invention also relates to a method for iteratively synthesizing, under spectral constraint, a noise having a power spectral density corresponding to a given template. The invention applies in particular to the submarine acoustic noise generators on board small-size autonomous craft.

Abstract: A connection for an underwater acoustics system connecting elements of an antenna embedded in a leaktight first block of the system and an electro-optical transmitter embedded in a separate leaktight second block of the system. The antenna is electrically connected to a first part of a divisible transformer, which is also arranged in the leaktight first block. The electro-optical transmitter (e.g., vertical cavity surface emitting laser) is electrically connected to a second part of the divisible transformer, which is also arranged in the leaktight second block. The first part and the second part are anatomically separated, as are the first and second blocks within which they are contained, but have cores that can magnetically communicate with one another. By this configuration, the divisible transformer can communicate signals from the antenna to the electro-optical transmitter without compromising the leaktightness of the first or second blocks, thereby protecting the components.

Abstract: To compensate for the effect of external parameters on piezoelectric sensors connected to a charge amplifier, a small portion of this sensor is used to form the feedback capacitor of the amplifier. These parameters then have the same effect on the sensor and on the capacitor, thus making it possible to provide compensation to hydrophones made of piezoelectric polymer material.

Abstract: A device for detecting water penetration into a marine acoustic streamer with segments interconnected by connectors. Each connector positioned between any two adjacent segments is provided with sensors which are constituted by flexible printed circuits having two distinct and interleaved conductive combs thereon. A bifilar line interconnects the sensors, and an emitting and receiving circuit allows a sensor whose impedance has been changed by the infiltration of water into the connector to be located by means of a reflectrometric method, whereby the operating condition of such marine acoustic streamer can be supervised efficiently and at low cost.