Raw P- and S-wave data from the DSI were processed to extract P- and S-wave slowness (inverse of velocity) in Hole 1173A. A phase-picking algorithm is used, fully described by Kozak et al. (2001), that is based on the Hilbert transform of time domain signals and typically uses 16 points per cycle to identify the arrival times of various wave modes. Real-time picking and semblance processing algorithms are often used for computation of P- and S-wave logs by commercial logging services (e.g., Kimball and Marzetta, 1984), but caution is advised if high-resolution results are desired or when enlarged hole conditions are present. In these cases, resolution may be lost by averaging across the receiver array or from noisy and unstable receivers at certain depths. Using the high-resolution phase-picking method and selecting receivers for processing improves the slowness estimates significantly. In addition, frequency filtering, wave propagation modeling, stacking, and other numerical techniques are used prior to the slowness picking to achieve the highest quality results.