Hydroacoustics, Inc.

Hyroacoustics, Inc.

David P Hollinger

John V Bouyoucos

David E Nelson

Dennis R Courtright

Robert J Hannon

In order to optimize detection of targets from a broadband return, a multiplicity of narrow bands are matched-filter processed simultaneously in parallel. The band or bands which provide the best joint combination of target and propagation in response are used for target detection.

Sonar system especially for shallow water application such as in littoral environments

A system for geophysical exploration uses a single source (,) which emits signals over multiple octaves. The source is driven by a composite sweep signal having two or more sweeps, one of which covers the lower octave (,) while the other sweeps cover the remainder of the bandwidth. The signals covering the lower portion are reduced in the case of a sweep which varies linearly with time in proportion to the square root of the ratio of the sweep rate of the signals covering the upper end to the sweep rate of the signals covering the lower end. The signals are transmitted simultaneously. Because of the composite sweep the same energy spectrum is transmitted as with a sine wave sweep which extends over the entire frequency band, while reducing the peak power and radiator displacement required at lower frequencies to maintain a flat spectrum. The size of the equipment can be reduced.

Geophysical exploration system using seismic vibrator source which provides a composite sweep

A signal processing system of reduced complexity over conventional banks of matched filters for each Doppler velocity of interest is responsive to a transmission which is in the form of a train of repeated Doppler invariant signals which are preferably phase continuous. The system utilizes a head end zero Doppler correlator and tapped delay line summer with summing nodes in cascade for each Doppler velocity of interest. The summer provides coherent sums indicative of the Doppler velocity of the target.

System for processing returns from a target from transmissions

Time Division Multiplex (TDM) telemetry of submultiplex sequences of signals which may be obtained from successive sections of sensors in a sensor array are transmitted synchronously by locking generators in each section, which determine the time slots in which samples of the sensor signals from each sensor in the array may be transmitted, to successive synchronizing pulses which are generated in the section of the array furthest from the head end of the array where the telemetered signals are received. The synchronizing signals are transmitted once per scan of all of the sensors in the array and phase or time the operation of clock generators and counters which establish the timing so that neither the time slots nor the sensor data signals which are transmitted therein to the collection point at the head end of the array interfere with one another. The sensor array may be a seismic array such as a seismic streamer or spread used in geophysical exploration. Data signals from groups of sensors associated with different data acquisition units of a chain of such units may also be telemetered in synchronous sequences during repetitive scans or frames. Each section or module of the system may be identical and can provide the synchronizing pulses to succeeding section if a preceding unit fails to provide the synchronizing signals.

Growing community of inventors

Avon, NY, United States of America

David P Hollinger