Post Stack Spectral Shaping of Seismic Data Using 2D Batch Control Monitor
          and Central Difference Operators: Case Studies from Kansas

                  J.F. Hopkins, R.W. Knapp, and N. Anderson


Frequency analysis and spectral shaping of seismic data are normally done 
during processing to attenuate unwanted noise from seismic sections and to
enhance resolution.  Landmark's BCM2D system provides the opportunity to
analyze and shape frequency spectra of post stack data in an easy and efficient
manner with almost instant feedback.  We propose a work-flow model that
includes the application of central difference operators to 'whiten' wavelet
frequency spectra.

Central difference operators are short (3-5 samples), zero phase, high-pass 
filters with constant slope (12 dB/octave modules).  They represent a
first-order approximation to the inversion of attenuation losses.  Spectral
balancing is accomplished in a consistent and direct manner with a filter that
is extremely time-efficient.  Amplification of high-frequency noise is
inherently avoided, and gentle high-cut properties are easily encoded.  
	
Application of central differencing to data from Kansas dramatically improved 
vertical resolution (up to 4X), accentuating and resolving thin intervals that 
were represented as mere inflections in the original data.  The process is a 
highly efficient means of enhancing vertical resolution which avoids many 
pitfalls of both deconvolution and 'standard' spectral whitening methods.