Abstract: This invention is a system that is capable of having a high dynamic range for the transmission of electrical information from an array of sensing devices to processing equipment via transmissions paths. A high gain quadrature multiplexer is coupled to the output of each pair of adjacent sensing devices and a low gain quadrature multiplexer is coupled to the output of each pair of adjacent sensing devices. The foregoing is arranged in such a manner that each sensing device is coupled to one channel of the multiplexer near it and to one channel of the adjacent multiplexer. A quadrature demultiplexer is coupled to the output of the high gain multiplexer and another quadrature demultiplexer is coupled to the output of the low gain multiplexer so that the faint signals received by the sensing devices will be passed to certain processing equipment through high gain channels and the loud signals detected by the sensing devices will be passed to processing equipment via low gain channels.

Abstract: Apparatus for determining the bearing of a remotely located source of an inging acoustic signal including a sonobuoy having a submerged package including a hydrophone array for producing omnidirectional and orthogonal directional signals, a combiner for combining the directional signals, and a single channel multiplexer including modulators and a compass driven resolver for providing a single channel multiplexer output signal carrying bearing information in a single frequency channel via a cable to a transmitter unit carried by a surface package of the sonobuoy. The transmitter unit transmits the single channel multiplexed information to a receiver whose output signal is applied to a demultiplexer for deriving a pair of phase shifted signals indicative of the omnidirectional acoustic signal received which pair have a relative phase shift equivalent to the bearing angle referenced to magnetic North.