Patent application number | Description | Published |
20100245119 | TWO-TIER STREAMER COMMUNICATION SYSTEM - A two-tier communication system for a seismic streamer. The communication system operates over an unshielded twisted-pair communication line extending the length of the streamer. Repeater units having a repeater function and a device controller function divide the twisted pair into line segments. Coils on each segment couple signals inductively to collocated external devices in a low-speed 2400 baud FSK data link between the devices and an associated device controller. A Gaussian 8-level FSK high-speed 60 kbit/s data link is established along all the segments with the repeaters re-transmitting boosted signals along the entire length of the communication line. The coils are transparent at the high-speed data rate. Time division multiple access (TDMA) or frequency division multiple access (FDMA) is used to accommodate the two links on the single twisted pair. | 09-30-2010 |
20110182140 | SEISMIC SYSTEM WITH GHOST AND MOTION REJECTION - An underwater seismic system for reducing noise due to ghost reflections or motion through the water from seismic signals. The system includes two motion sensors. One sensor has a first response and is sensitive to platform-motion-induced noise as well as to acoustic waves. The other sensor has a different construction that isolates it from the acoustic waves so that its response is mainly to motion noise. The outputs of the two sensor responses are combined to remove the effects of motion noise. When further combined with a hydrophone signal, noise due to ghost reflections is reduced. | 07-28-2011 |
20120027132 | GFSK RECEIVER ARCHITECTURE AND METHODOLOGY - A Gaussian Frequency Shift Key (GFSK) receiver includes a receiver front end to receive a GFSK-modulated signal and convert the received GFSK-modulated signal to a baseband frequency modulated signal, a channel filter to reduce channel interference which is adjacent to a desired channel of the baseband frequency modulated signal, a demodulator to demodulate the channel filtered baseband modulated signal and to recover a sequence of symbols, a digital filter to reduce inter-symbol interference (ISI) from the sequence of symbols, a slicer to produce symbol decisions based on the filtered sequence of symbols, and a symbol-to-bit mapper to map the symbol decisions to data bits. | 02-02-2012 |
20120057430 | MULTI-COMPONENT, ACOUSTIC-WAVE SENSOR AND METHODS - A multi-component sensor of a fluid-borne acoustic wave that senses pressure and up to three orthogonal particle motion components. The sensor is unresponsive to motion of the sensor mount. Furthermore, the sensor is substantially unresponsive to the turbulent flow of the acoustic medium past the sensor. | 03-08-2012 |
20140328138 | SEISMIC SYSTEM WITH GHOST AND MOTION REJECTION - An underwater seismic system for reducing noise due to ghost reflections or motion through the water from seismic signals. The system includes two motion sensors. One sensor has a first response and is sensitive to platform-motion-induced noise as well as to acoustic waves. The other sensor has a different construction that isolates it from the acoustic waves so that its response is mainly to motion noise. The outputs of the two sensor responses are combined to remove the effects of motion noise. When further combined with a hydrophone signal, noise due to ghost reflections is reduced. | 11-06-2014 |
Patent application number | Description | Published |
20080285380 | SEISMIC STREAMER WITH IRREGULARLY SPACED HYDROPHONES - A seismic streamer and a method for positioning a group of hydrophones in a seismic streamer. The hydrophones in a group are spaced irregularly along the length of the streamer to reduce the influence of bulge-wave noise and flow noise on the hydrophone group response. The irregular spacing may be produced as pseudorandom deviations of the actual positions of the hydrophones from a nominal uniform spacing of hydrophones. | 11-20-2008 |
20090103509 | ENHANCED WIRELESS PACKET DATA COMMUNICATION SYSTEM, METHOD, AND APPARATUS APPLICABLE TO BOTH WIDE AREA NETWORKS AND LOCAL AREA NETWORKS - A cellular wireless packet data communication system containing transmit-only endpoint devices which transmit to receive-only base stations. The system is configured to allow for large area coverage (e.g., a metropolitan area) with far fewer number base stations than are required with conventional two-way cellular systems. The base station coverage areas are configured to overlap, allowing for reception of packets at multiple base stations. A data concentrator resolves redundantly received messages. The network is configurable as a WAN, a LAN, or a combination of the two. Novel modulation techniques (e.g., a 16QAM submodulation together with a 7FSK modulation) are used such that low cost components can be used in the transmitters and receivers while achieving outstanding probability of success performance. The endpoint devices are battery operated and accordingly, are designed for low power consumption and multi-year battery life. The system is used in a variety of applications including remote monitoring and mobile communications. | 04-23-2009 |
20090251994 | SEISMIC VIBRATOR ARRAY AND METHODS OF OPERATION - An arrangement for conducting a seismic survey and methods for operating a vibrator array in a seismic survey. A signal source coupled to an array of vibrators drives the vibrators with a set of signals to generate seismic signals into a survey area. Each of the signals of the set has an autocorrelation function and a cross correlation function with the other signals of the set that decays faster with time than reflections of the seismic signals from the survey area. One such set of signals includes a linear FM sweep phase-modulated by a maximal-length sequence code shifted a different number of chips for each signal. | 10-08-2009 |
20130195040 | GEOGRAPHIC LOCATING REMOTE ENDPOINT MONITOR DEVICE, SYSTEM, AND METHODOLOGY THEREOF - A phase-locked loop frequency synthesizer includes an L-state pulse width modulator configured to receive a reference frequency signal and at least one entry from a frequency table, and to output at least one N/N+1 modulus signals corresponding to the at least one entry from the frequency table. The synthesizer includes a divide by N/N+1 controllable modulus divider configured to receive the at least one N/N+1 modulus signals and to divide the output frequency signal by the at least one N/N+1 modulus signals to generate a second reference frequency signal. The synthesizer includes a phase frequency detector configured to receive the reference frequency signal and the second reference frequency signal and to generate an error signal. The synthesizer also includes a filter network configured to receive the error signal and to output a voltage; and a voltage controlled oscillator configured to receive the voltage and to generate the output frequency signal. | 08-01-2013 |
20140320182 | GEOGRAPHIC LOCATING REMOTE ENDPOINT MONITOR DEVICE, SYSTEM, AND METHODOLOGY THEREOF - A phase-locked loop frequency synthesizer includes an L-state pulse width modulator configured to receive a reference frequency signal and at least one entry from a frequency table, and to output at least one N/N+1 modulus signals corresponding to the at least one entry from the frequency table. The synthesizer includes a divide by N/N+1 controllable modulus divider configured to receive the at least one N/N+1 modulus signals and to divide the output frequency signal by the at least one N/N+1 modulus signals to generate a second reference frequency signal. The synthesizer includes a phase frequency detector configured to receive the reference frequency signal and the second reference frequency signal and to generate an error signal. The synthesizer also includes a filter network configured to receive the error signal and to output a voltage; and a voltage controlled oscillator configured to receive the voltage and to generate the output frequency signal. | 10-30-2014 |