Rowe-deines Instruments, Inc.

Other

Doppler, Ltd.

Rd Instruments, Inc.

Kent L Deines

Blair H Brumley

Eugene A Terray

Ramon G Cabrera

Mark A Vogt

Raymond Lee Gordon

Steve J Maier

A digital audio distribution network includes a plurality of nodes and at least one transmission line that interconnects the nodes to form the digital audio distribution network. A first node in the plurality of nodes receives a user command, encodes the user command, and sends the encoded user command and digital audio over the transmission line. A second node in the plurality of nodes receives the encoded user command and the digital audio over the transmission line.

Digital audio distribution network

A system for measuring velocity of a target is disclosed. In one embodiment, the system includes a laser device, a detector and a signal processor. The laser device produces a frequency-modulated laser beam, wherein the frequency-modulated beam is split into at least two laser beams, wherein a reflected beam comprising one split beam is directed to the target and reflected from the target. The detector detects a combination of the reflected beam and a reference beam comprising another split beam, wherein the reflected beam and the reference beam have unequal delays. The signal processor obtains velocity information from the combined beam by use of Doppler-shifted harmonics of the modulation frequency.

System and method for measuring velocity using frequency modulation of laser output

The invention relates to a system for measuring velocity. In one embodiment, the system includes a laser assembly having a laser diode and a power detection diode. The laser diode emits a plurality of laser signals which are frequency-modulated, wherein a selected one of the frequency-modulated signals is directed to and reflected from a target, and wherein another selected one of the frequency-modulated laser signals transmitted via one signal path is combined with the reflected laser signal transmitted via another delayed signal path in the interior of the laser assembly. The power detection diode detects the combined signal. The system also includes a signal processor configured to obtain velocity information from the detected signal by use of the harmonic frequencies associated with the modulation frequency.

The invention relates to a system for measuring velocity. In one aspect of the invention, the system comprises a laser emitting device, an optics assembly, a combiner and a signal processor. The laser emitting device generates a frequency-modulated laser signal. The optics assembly splits the frequency modulated signal into a plurality of laser signals, and directs the split signals to a target and receives at least one signal reflected from the target. The combiner receives one of the split signals transmitted via one signal path and the at least one reflected signal transmitted via another signal path, and multiplies the received signals. The signal processor extracts velocity information from the multiplied signal.

Fluid flow in a conduit is measured with an acoustic Doppler system installed in an opening in the pipe. The Doppler system may include transducers and driving circuitry to produce narrow beam pulses of acoustic energy. The transducers may be coupled to an acoustic refractive lens which is sealed in the opening.

System and method for flow measurement in a pipe

An electronic heading and attitude sensing subsystem which is fully integrated with the existing hardware of an acoustic Doppler current profiler (ADCP) oceanographic sonar suite to reduce the size and complexity of the apparatus. The subsystem uses a tri-state drive signal with relaxation periods and integration windows to synchronously drive the fluxgate magnetic sensors while reducing the effects of non-linearities and higher order harmonics which may result in heading errors. The present invention includes an electrolytic tilt sensor device and driving circuit which allow measurement of system vertical orientation without the effects of electrolyte conductivity are described. The present invention further includes methods of system calibration, magnetic perturbation modeling, and heading calculation.

Electronic compass and attitude sensing system

A system and method for measuring current velocities using coded-pulse broadband acoustic signals. Autocorrelation of two phase coded pulses which are in the water during a single transmission cycle is used to calculate a Doppler frequency. The effective result is current profilers having improved profiling range and spatio-temporal resolution.

Broadband acoustic doppler current profiler

Broadband acoustic Doppler current profiler

A system and method for bottom tracking in a sonar system. The present invention provides for convolving the received signal with the second derivative, or an approximation thereof, of the matched transmitted pulse. In another aspect of the invention, the received signal is convolved with the matching transmitter pulse and the result is evaluated by summing the differences between a central peak and its neighboring left and right values. The filtering of the present invention removes the effect of water absorption on signal amplitude. The invention also includes compensating for spreading loss in the received signal.

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Poway, CA, United States of America

Kent L Deines