Method for correction of clock drift in seismic nodes, a seismic node and a seismic node handling system
AssigneeInapril AS
InventorOistein Aanensen
Life of this patent
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Abstract
A method of correcting clock drift in at least one slave clock in a seismic node. The method comprises obtaining a number of clock drift measurements of the at least one slave clock in the at least one seismic node. A clock drift correction function as a function of time is calculated by curve fitting the number of clock drift measurements to a 2nd order polynomial. A time of reference of the recorded seismic sensor data is corrected by the 2nd order polynomial clock drift correction function.
Claims16
A method for correcting for clock drift of at least one slave clock in at least one seismic node after a seismic recording by the at least one seismic node on a seabed resulting in data sets of recorded seismic sensor data as a function of time, the method comprising:
- obtaining at least one clock drift measurement of the at least one slave clock before deployment of the at least one seismic node into the sea;
- obtaining at least two clock drift measurements of the at least one slave clock after recovery of the at least one seismic node from the seabed;
- and
- calculating a clock drift correction function of the at least one seismic node slave clock by curve fitting, to a 2nd order polynomial, (i) the at least one clock drift measurement obtained before the deployment and (ii) the at least two clock drift measurements obtained after the recovery.
A seismic node adapted for performing a seismic recording on a seabed resulting in data sets of records seismic sensor data as a function of time, the seismic node comprising:
- a slave clock;
- and
- a processor configured to
- obtain at least one clock drift measurement of the slave clock before deployment of the seismic node into the sea,
- obtaining at least two clock drift measurements of the slave clock after recovery of the seismic node from the seabed, and
- calculating a clock drift correction function of the seismic node slave clock by curve fitting, to a 2nd order polynomial, (i) the at least one clock drift measurement obtained before the deployment and (ii) the at least two clock drift measurements obtained after the recovery.
A handling system for at least one seismic node adapted for performing a seismic recording on a seabed resulting in data sets of recorded seismic sensor data as a function of time, wherein the at least one seismic node comprises at least one slave clock the handling system comprising:
- a master clock;
- and
- a processor configured to
- obtain at least one clock drift measurement of the at least one slave clock before deployment of the at least one seismic node into the sea;
- obtain at least two clock drift measurements of the at least one slave clock after recovery of the at least one seismic node from the seabed;
- and
- calculating a clock drift correction function of the at least one seismic node slave clock by curve fitting, to a 2nd order polynomial, (i) the at least one clock drift measurement obtained before the deployment and (ii) the at least two clock drift measurements obtained after the recovery.
A non-transitory computer-readable medium having a computer program stored thereon, which when executed by a processor, cause the processor to perform:
- obtaining at least one clock drift measurement of the at least one slave clock before deployment of the at least one seismic node into the sea;
- obtaining at least two clock drift measurements of the at least one slave clock after recovery of the at least one seismic node from the seabed;
- and
- calculating a clock drift correction function of the at least one seismic node slave clock by curve fitting, to a 2nd order polynomial, (i) the at least one clock drift measurement obtained before the deployment and (ii) the at least two clock drift measurements obtained after the recovery.
Dependencies are inferred from the claim text.