Fourier Transform > Convolution with reflectivity function

All filtering of an entry signal e(t) is the product of a convolution between the impulse response of the filter r(t) and the signal e(t).
In geophysics, e(t) is the signal source and r(t) is the reflectivity of the substrata. The result of this filtering gives the seismic trace recorded by a sensor. The reflectivity of the substrata is represented here as being a suite of Diracs of varying position and amplitude. Convolution by each Dirac introduces a translation and a variation in the amplitude of e(t) (Convolution product : application to the translation of a wavelet). The sum of the translated Diracs constitutes the seismic trace.