A new result in the seismic data acquisition method

This paper is intended for rapid dissemination of the results the authors have obtained in the method of seismic data acquisition which features remarkably enhanced resolution, totally eliminated side-lobes of the compressed version of the excitation signal, and greatly improved signal-to-noise ratio, using the identical field equipments, at the same intensity of excitation, as compared as the conventional "Vibroseis" system. The currently popular VIBROSEIS system developed by P. L. Goupillaud et al has been contributing rather fruitfully to the seismic exploration industry since the 60 s. However, it has the shortcomings that (1) the autocorrelation function of the "Chirp" signal used has a relatively pronounced cluster of side-lobes which give rise to undesirable coherent interference, (2) improving the resolution of the data acquired demands more costly vibrators of wider bandwidths, (3) vibrators of more massive construction are recommended for resolution enhancement because of greater excitation power required, and (4) the signal-to-noise ratio of the processed output from the correlator cannot promise the optimality since the random noise output from the geophones is non-white in nature. A new method of seismic data acquisition has been developed by the authors which improves the performance in all the above aspects and more. The new method employs the same field equipments as used in the Vibroseis system. The new method is called NOVA method by the authors. The paper will recount the reasons why the conventional Vibroseis system cannot get rid of the above drawbacks, and the improved results of the NOVA system will be reported for comparison. The disclosure of the working principle of the NOVA system will appear in a later paper.