CONSIDERATIONS IN ESTIMATING THE MINIMUM‐PHASE PROPERTIES OF SAMPLED DATA*

Analysis of the phase spectra from the signatures, impulse responses and other wavelets observed in seismic data leads to the construction of equivalent minimum‐phase functions. The accuracy of such computations using digitally sampled data is questioned with special reference to Texas Instruments DFS IV and DFS V recording filters. Results vary with the lengths and sample rates of the time functions, and further errors may be introduced when implementing the Hilbert transform. Such problems are related to poor resolution in the low amplitude areas of the spectrum. Techniques for correction are described. With appropriate shaping a reasonably accurate phase spectrum may be computed for the minimum‐phase function. The generation of minimum‐phase wavelets within the processing sequence is briefly discussed.