Abstract: The invention relates to a simulator for providing waveforms of the type produced at a receiver from a sonobuoy transmission. The simulator signal includes a component representing reverberation under different sea state conditions and a component representing echo pulses received from a target having relative motion with respect to the sonobuoy. Selected initial range and target speed values can be set in the simulator so that the signal includes a sequence of echo pulses having the varying delay and doppler shift which would occur from a target starting at the selected range and moving at the selected speed.

Abstract: A high resolving power arrangement of transmitting and receiving transducer for arrays the detection of targets in a wave detection system such as sonar. The arrangement includes a transmitting array including two transducers (T.sub.1) and (T.sub.n) transmitting in synchronism or alternatively in phase opposition and a receiving array including transducers T.sub.1, T.sub.2 . . . T.sub.n associated respectively with multiple connector phase shifters (D.sub.1), (D.sub.2) . . . (D.sub.n).

Abstract: The invention relates to a transmit/receive switching unit for use between a transmit/receive converter and the transmission line of a transmit/receive device having a voltage source. The unit has transmitting and receiving channels with the receiving channel having a signal amplifier. An energy storage element such as a capacitor stores a part of the transmission energy on a continuing basis for operating the signal amplifier in the receiving channel. This scheme saves having to provide a separate line from a voltage source to the amplifier.

Abstract: A multipoint reflective target system for use as sonar targets. The system ncludes a plurality of small spaced apart reflectors that are interconnected by an elongated flexible tether. The tethered reflectors are then towed in the ocean and form an elongated multipoint reflective target comprising a string of spaced apart reflectors moving under and about parallel to the ocean surface. This target is sonified by a sonar pulse and generates a reflected signal having a predetermined shape. The shape of the reflected signal is determined by a selection of parameters such as the length of sonar pulse, the spacing of the reflectors and the size and material of the reflectors. By properly selecting these parameters it is possible for the multipoint reflective target system to resemble much larger actual or similated targets.

Abstract: A way of automatically inspecting a machined part, for example, to a tolerance of 0.001 inches. A minicomputer monitors a change in phase, for example, of wave energy impinging upon a sample part and compares it with a change in phase of such energy for a standard or master part, any difference between the monitored changes being interpreted to determine if the sample is within acceptable tolerance limits. The inspection approach described uses no moving parts and can be used to inspect many dimensions of a part simultaneously in less than a second. Acoustic waves or microwave electromagnetic wave energy can be used to inspect parts of any shape. The inspection system disclosed can be used, as well, to monitor the geometry of an object over time to note any changes in said geometry. And the concepts of the inspection system can be employed in conjunction with robot-controlled devices to provide close-positioning data for such devices.

Abstract: The apparatus comprises an ultrasonic transducer for the purpose of scanning an examination subject, and an image display device for representation of the ultrasonic information signals in the form of a display image. In accordance with the illustrative disclosure, an arrangement of electric frequency filters is associated with the ultrasonic transducer, said frequency filters manifesting a frequency response which is essentially the inverse of the frequency response being imposed on the ultrasonic impulses by the attenuating examination subject in the ultrasonic-transmit path. The imaging apparatus finds application particularly in medical ultrasonic diagnosis.

Abstract: A reverberation backscatter measurement system for providing in situ measment of acoustic backscatter levels from point source scatterers or the target size of individual scatterers within or at the boundaries of the transmitting medium. The volume scattering strength, a calculated value from measured data, is the logarithmic ratio of the reflected intensity to the incident intensity at a unit distance from the acoustic center of the scatterers. The system accurately measures the parameters of volume scattering strength (S) and target strength (TS) and has application in the measurement and determination of sonar system performance and target strengths of vessels and their wakes. It also may be used in fisheries for biological studies in zooplankton population and distribution assessments. A data processing system is also provided to effectively and accurately process reflected signals indicating target strength and scattering strength.