Abstract Maroni, C.-S., Quinquis, A., and Vinson, S., Horizon Picking on Subbottom Profiles Using Multiresolution Analysis, Digital Signal Processing 11 (2001) 269–287 A fully automatic algorithm is proposed for the mapping of sediment layers on subbottom profiles. This mapping should significantly speed up data analysis and sedimentary data base building. The proposed method combines two techniques: edge following algorithms and multiresolution analysis using the wavelet transform. Image analysis at different scales allows us to follow sediment layer contours without interruption, and with adequate accuracy. In order to reduce detection errors a thresholding with hysteresis is first performed. The thresholds are automatically set according to data distribution. Performances of the algorithm are discussed, from testing on a set of real subbottom profile data.