Nonstretch NMO by constant NMO correction (CNMO)


The application of traditional NMO-correction techniques in the processing of seismic data may result in severe distortion. This distortion is observed as a decrease in frequency content (NMO stretch). This may be seen as the source of problems in the processing with stretch. In this paper, CNMO method is applied which doesn't have the `stretching effects' of conventional NMO correction. Unlike conventional NMO, the technique implies constant normal moveout (CNMO) for a finite time interval of a seismic trace. The benefits of the CNMO method in relation to the traditional NMO method include preservation of higher frequencies and reduction of spectral distortions at far offsets. The need for severe muting after the correction is reduced, allowing longer spreads for CMP stack. The CNMO technique has been tested on synthetic and real data. The method may improve the resolution of CMP stack. The only assumption for this stretch-free NMO correction is that all time samples of a reflected wavelet at a particular offset have the same normal moveout