| 摘要 |
1,175,984. Processing seismic data. MOBIL OIL CORP. 3 May, 1967 [3 May, 1966], No. 20582/67. Heading H4D. In the processing of a seismic signal I(t) it is known to auto-correlate I(t) over a time interval t 1 to t 2 and to derive (e.g. by an analogue or digital computer) from the auto-correlation function the characteristics required for an inverse filter 24; it is stated that the " perfect " inverse filter may give rise to an undesired output signal component of large amplitude; according to the invention, the inverse filter is " stabilized " against such an event by effectively introducing white noise. In the first embodiment such introduction is made by adding a pulse from source 17, the pulse amplitude being between 0À1% and 10% of the peak value of the auto-correlation function. In another embodiment noise from a generator is added to input signal I(t), Fig. 9 (not shown). In the first embodiment a band-pass filter 26, see also Fig. 7 (not shown), is added to allow for the characteristics of the inverse filter at low and high frequencies.
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