Low-frequency signal enhancement by pseudo-Vz deghosting

We examine the estimation of the vertical component of particle motion (‘pseudo-Vz’) data from deep-tow streamer pressure data. The estimated data is then combined with the pressure data to attenuate the pressure ghost by a procedure referred to as pseudo-Vz deghosting. The notches created by the destructive interference of the up- and down-going waves at the receivers are shown to be ‘filled’ with information about the upgoing waves, thereby improving the signal-to-noise ratio. In addition, it is shown that even though they may not be present in the input data, by including sparsity constraints in the deghosting process, coherent and energetic signals at the low-frequency part of the spectrum can be estimated using this technique. The enhanced signals at notch frequencies provide broadband data. The proposed technique can be used, for example, for future deep-tow marine seismic data acquisition benefiting from higher signal-to-noise ratio at greater streamer depth, as well as in re-processing of existing data, for example in a time-lapse scenario, making them more comparable to future broadband data. We demonstrate the technique on a 2D deep-tow marine seismic data set acquired along a transect on the Sumatra subduction zone, in southwest Indonesia.