Multicomponent seismology is a useful tool for enhanced reservoir characterization of heavy-oil fields. As shown by Watson et al. (2002) and Lines et al. (2005), multicomponent data can provide maps of the P-wave to S-wave velocities (VP/VS), and these VP/VS maps provide important information about lithology and reservoir changes. In this discussion, we show that VP/VS mapping, as derived from traveltime measurements on vertical and radial component data, is a robust procedure. We explore two aspects of this type of VP/VS mapping. First, we explore the spectral differences of PP and PS seismic volumes and design band-pass filters that can significantly improve the quality of VP/VS maps. Second, we perform an error analysis of this mapping and show that the derivation of VP/VS maps from reflection traveltime picks is not overly sensitive to the choice of reflecting horizons above and below the reservoir.