Polarity preserving decon in ``N log N'' time

Definition of Ricker wavelet

We use the term ``Ricker wavelet'' to describe any wave shape resembling the second derivative of a Gaussian. The reason Ricker wavelets are so prevalent in marine seismology is this: The water surface negative reflection coefficient causes two ghosts, one at the gun, the other at the receiver. At each location the slightly delayed surface reflection (of negative polarity) applies a finite difference to the image. Consequently, any impulsive reflector looks like a band-limited second derivative. Land seismometers measure neither displacement nor velocity. Essentially, they are devices that measure acceleration. Band limiting their output again produces wavelets like the Ricker wavelet.