2026/07/31 by Tengku Afrizal Tengku Ali, Badrul Hisham Ismail
Earth and Planetary Sciences · Environmental Science · #Coastal and Marine Dynamics #Consistency (knowledge bases) #Estuary #Marine and fisheries research #Port (circuit theory) #Residual #Seabed #Sonar #Underwater Acoustics Research
paper · doi:10.1080/01490419.2026.2708101
crossref issued 2026/07/31 · crossref published 2026/07/31 · crossref published-online 2026/07/31 · openalex publication_date 2026/07/31 · crossref created 2026/07/31 · crossref deposited 2026/07/31 · crossref indexed 2026/07/31 · openalex created_date 2026/08/01 · openalex updated_date 2026/08/01
Depth residuals used as seabed-roughness descriptors in acoustic seabed classification contain both true seabed roughness and beam-angle-dependent instrument noise, which can produce classification artifacts that follow sonar geometry rather than substrate. The A-priori Multibeam Uncertainty Simulation Tool (AMUST) predicts the instrument component of depth uncertainty, but published evaluations are confined to European sandy-shelf settings. This study tests whether AMUST transfers to a shallow tropical estuarine port and evaluates an appropriate parameterization for patch-residual comparison. Two repeat Kongsberg EM2040C dual-head surveys of the same Port Klang channel, acquired at different phases of the maintenance-dredging cycle, give a controlled comparison in which sonar, vessel, and site are fixed while the seabed changes from a smooth floor to a dredge-scarred surface. Patch-based biquadratic detrending applied to 88,599 smooth-floor and 218,970 dredge-scarred patches was compared with AMUST through the ratio r=σmeas/σAMUST. Reported as the inner-swath (|θ| ≤ 20°) mean, the ratio was 0.86 for the smooth-floor survey (86.7% of patches uncertainty-dominated) and 1.47 for the dredge-scarred survey (43.1%), with mean corrected roughness rising from 0.0017 to 0.0132 m. The ratio cleanly separates the two regimes, indicating that AMUST can provide a transferable, physics-based reference for isolating instrument noise from patch-residual roughness in tropical ports.