Step 4: Shaping the pseudo-trace

These pseudo-traces will have approximately the correct phase spectrum (cubing preserves arrival times), but the original HF amplitude information is lost when the data are partitioned in frequency. In the case of data traces though, we can find for each trace the filter which best shapes the amplitude spectrum of the pseudo-trace to the HF data. This filtering can be zero-phase, but in case the reflection wavelets are not themselves zero-phase, some phase information can be modeled in the shaping filter.