Patent application number | Description | Published |
20080229825 | Accelerometers - A fibre optic accelerometer particularly intended for use with an interferometer using the compliant cylinder approach but further providing a seismic mass at the core of the cylinder resulting in improved sensitivity and rejection of out-of-axis inputs. | 09-25-2008 |
20080277568 | Traffic Sensing and Monitoring Apparatus - Traffic sensing and monitoring apparatus ( | 11-13-2008 |
20090080828 | Fibre Optic Sensor Array - A fibre-optic sensor array ( | 03-26-2009 |
20090087136 | Fibre Optic Sensor Package - A fibre-optic sensor package ( | 04-02-2009 |
20100098114 | Frequency Control Method and Apparatus - A feedback control circuit and method for controlling laser frequency employing an interferometric phase sensor which accepts a light output from a laser and combines a phase modulated version of the light output, with an unmodulated version. By modulating only one component of the signal in the interferometric sensor, the improved noise characteristics are obtained, while demodulation can be performed relatively easily and cheaply. Methods and enclosures for reducing ambient noise in an interferometer or the delay coil thereof are also described. | 04-22-2010 |
20120017687 | Remote Sensing - A plurality of sensors output information into a distributed acoustic sensing (DAS) system via acousto-mechanical signals. The sensors are coupled to the optic fibre at the centre of the DAS system indirectly, the acousto-mechanical signal being transmitted via an intermediary body, such as the ground or a conduit. | 01-26-2012 |
20120057432 | Well Monitoring by Means of Distributed Sensing Means - This application describes methods and apparatus for downhole monitoring in real-time. The method involves interrogating an unmodified optic fibre ( | 03-08-2012 |
20120063267 | Well Monitoring by Means of Distributed Sensing Means - Methods and apparatus for downhole monitoring are provided by interrogating an unmodified optic fibre ( | 03-15-2012 |
20120111560 | Fracture Monitoring - This application relates to methods and apparatus for monitoring hydraulic fracturing during oil/gas well formation. A fibre optic cable ( | 05-10-2012 |
20120188533 | Phase Based Sensing - A method of distributed acoustic sensing (DAS) whereby the derivative or rate of change of a signal backscatted from a fibre is measured. The change, or derivative of the phase measured in this way has a much smaller amplitude than the signal itself if the difference between the two times at which the signal is measured is much less than the period of the signal being measured, resulting in lower sensitivity. Frequency shifts can be applied to temporally displaced return signals to compare the rate of change, for example by employing an output interferometer arranged to modulate the signal in each arm by a different frequency shift. | 07-26-2012 |