Seismic Profiling with a Parametric, Self-Demodulated Ricker Wavelet

The nonlinear self-demodulation of a burst of high frequency sound produces a highly directive, low frequency transient in the parametric array process. Ricker wavelets, of interest in exploration seismology, can be generated from the self-demodulation of a primary pulsed in a Gaussian envelope. The application of this process to sub-bottom profiling is explored in terms of resolution and depth of penetration. Sea trials conducted in a complicated geological area offshore Oahu, Hawaii, U.S.A., are discussed. It is shown that parametric operation can lead to greater depth of penetration in the sediments for systems compared on the basis of equal angular resolution and transducer size.