Phase based sensing
AssigneeOptasense Holdings Limited
InventorsRoger Ian Crickmore, Jolyon DeFreitas, Philip John Nash
Life of this patent
Estimating the term…
Abstract
A method of sensing using a phase based transducer in which a transducer response is provided at multiple different levels of sensitivity. The different levels of sensitivity are used to produce an output which does not overscale across a wide range of signal levels. This is particularly useful for use in conjunction with multiplexed arrays of fiber optic sensors for seismic surveying. Methods of sensor calibration and noise reduction are also described.
Claims15
A method of sensing using a phase based transducer comprising:
- providing a plurality of signals representative of the transducer response, said plurality of signals having different sensitivities,
- determining a value of amplitude of the transducer response using at least one of said signals, and
- based on said value, using one or more signals of different sensitivities to provide a sensed output.
A method of sensing using a phase based transducer comprising:
- providing a plurality of signals representative of the transducer response, said plurality of signals having different sensitivities,
- determining a value of amplitude of the transducer response using at least one of said signals,
- determining, from said value of amplitude, a level of overscale for the signals at each level of sensitivity and
- based on said value, using one or more signals of different sensitivities to provide a sensed output.
A method of sensing using a phase based transducer comprising:
- providing a plurality of signals representative of the transducer response, said plurality of signals having different sensitivities,
- determining a value of amplitude of the transducer response using at least one of said signals, and
- based on said value, using one or more signals of different sensitivities to provide a sensed output wherein the highest sensitivity signal which is not subject to overscale is selected to be used to provide said sensed output.
A system for interrogating a phase based transducer comprising:
- a source for providing an interrogation signal to an input of said transducer
- a detector for receiving the signal output from the transducer in response to the interrogation signal, and
- a signal processor for providing a plurality of signals representative of the transducer response, said plurality of signals having different sensitivities, and using said plurality of signals adaptively to provide an output across a full range of sensed signal levels.
A method of operating a seismic array, comprising:
- receiving a plurality of outputs of differing sensitivities from each sensor;
- determining a first value of each sensor output on the basis of one or more of said plurality of signals;
- selecting one or more of said plurality of signals on the basis of the determined first value of each sensor output;
- deriving a final value of the sensor output on the basis of said one or more selected signals;
- and
- producing seismic information by using the final values of the sensor outputs from the sensors in the array.
Dependencies are inferred from the claim text.