Introduction to matched filters

John C. Bancroft

Matched filters are a basic tool in electrical engineering for extracting known wavelets from a signal that has been contaminated by noise. This is accomplished by crosscorrelating the signal with the wavelet. The cross-correlation of the vibroseis sweep (a wavelet) with a recorded seismic signal is one geophysical application. Another geophysical application is found in Kirchhoff migrations, where the summing of energy in diffraction patterns is equivalent to a two-dimensional cross-correlation.

The basic concepts of matched filters are presented with figures illustrating the applications in one and two dimensions.