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US 5,555,530 AGranted
Method for improving signal to noise ratio
AssigneeSchlumberger Technology Corporation
InventorRichard J. Meehan
Life of this patent
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AssigneeSchlumberger Technology Corporation
InventorRichard J. Meehan
Estimating the term…
A method for improving the signal to noise ratio from a pair of detectors such as geophones which each detect a noisy signal comprising a signal of interest (S) and a noise signal (N), wherein the signal of interest (S) has a different moveout across the pair of detectors from that of the noise signal (N), and the noise signal (N) from a given source is detected at the first detector at a time .DELTA.t before the corresponding noise signal is detected at the second detector, the method comprising delaying the noisy signal (S+N) detected at the first detector by an amount .tau. being greater than the moveout of the signal of interest but not more than .DELTA.t and subtracting the delayed signal from that detected at the second detector by means of an adaptive filter so as to minimize the power in the resultant signal. The signal detected at the first detection and optionally the resultant signal can also be delayed by an amount .tau..sub.2 and the signal detected at the second detector is subtracted from the delayed first detector (and resultant signals) by means of an adaptive filter so as to minimize the power in the final signal, the delay .tau..sub.2 being greater than the moveout of the signal of interest plus the length of the filter but not more than .DELTA.t plus the length of the filter.
A method for improving the signal-to-noise ratio from a pair of seismic detectors which each detect a noisy signal comprising a seismic signal (S) and a noise signal (N), wherein the seismic signal (S) has a different moveout across the pair of seismic detectors from that of the noise signal (N), the noise signal (N) from a given source is detected at the first detector at a time .DELTA.t before the corresponding noise signal is detected at the second detector, and the separation of the detectors is such that the noise signal (N) detected at the second detector is substantially the same as that detected at the first detector, the method comprising delaying the noisy signal (S+N) detected at the first detector by an amount .tau. being greater than the moveout of the seismic signal but not more than .DELTA.t and subtracting the delayed signal from that detected at the second detector by means of an adaptive filter so as to minimize the power in the resultant signal, yielding a representation of the seismic signal with attenuated noise level.
A method for improving the signal-to-noise ratio from a pair of seismic detectors which each detect a noisy signal comprising a seismic signal (S) and a noise signal (N), wherein the seismic signal (S) has a different moveout across the pair of seismic detectors from that of the noise signal (N), and the noise signal (N) from a given source is detected at the first detector at a time .DELTA.t before the corresponding noise signal is detected at the second detector, and the separation of the seismic detectors is such that the noise signal (N) detected at the second detector is substantially the same as that detected at the first detector, the method comprising delaying the noisy signal (S+N) detected at the first detector by an amount .tau..sub.2 and subtracting the signal detected at the second detector from the delayed signal by means of an adaptive filter so as to minimize the power in the resultant signal, the delay .tau..sub.2 being greater than the moveout of the signal of interest plus the length of the filter but not more than .DELTA.t plus the length of the filter, yielding a representation of the seismic signal with attenuated noise level.
A method as claimed in claim 8, wherein the pair of seismic detectors form part of a larger seismic detector array.
A seismic detector system for improved signal-to-noise ratio performance comprising:
A seismic detector system for improved signal-to-noise ratio performance comprising:
Dependencies are inferred from the claim text.