| 摘要 |
1,197,622. Data signal processing. TEXAS INSTRUMENTS Inc. 14 July, 1967 [18 July, 1966], No. 32448/67. Heading G4G. [Also in Division H4] In the time-domain filtering of a seismic trace (record) (see Division H4), different filter functions respectively optimum for filtering the trace at different record times are applied in turn to the trace by analogue apparatus. Time-delayed versions of the trace are reproduced by playback heads 20a from record drum 20 and applied to sets of summing resistors 32, 42 &c. which are selected by ganged switches 31, 41 &c., whereby resistors 32 and adder 33 apply a first filter function to the trace, then resistors 42 and adder 43 apply a second filter function to the trace, and so on. Smooth changeover between filter functions is achieved by means of timevaried resistors 34, 44 &c. for weighting the filter outputs. The filter outputs are combined in adder 36 and recorded at 23. Instead of resistor networks, voltage-controlled multipliers and gate circuits may be used for weighting and combining the outputs of heads 20a (Fig. 4, not shown). |
