A fast-correlation algorithm for swept-frequency seismic data

The controlled-source seismic reflection method using a so-called "swept-frequency" requires the application of a digital matched filter in the data preprocessing. The filter is of the swept-frequency form and it is normally long. With a 125 Hz aliasing frequency, 4 ms-sampled filters can commonly consists of up to 5000 samples. For the professor unfortunate enough to not possess a hard-wire correlator in his computer, the application of the matched filter is almost prohibitively time consuming and costly. The subject algorithm ignores any end tapering of the filter, and it concentrates only on the positions of the filter peaks and troughs. The computational savings to be realized can be around an order of magnitude, with essentially no loss in accuracy resulting.