| 摘要 |
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 minimise 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 2 and the signal detected at the second detector is subtracted from the delayed first detector (and resultant signals) by means of an adaptive fitler so as to minimise the power in the final signal, the delay tau 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. <IMAGE> |
