ASSESSING THE EFFECTIVENESS OF AN AUV EQUIPPED WITH A PHASE MEASURING BATHYMETRIC SONAR FOR SEDIMENTATION CONDITION SURVEY IN LAKE HOURAI (URE DAM)

Abstract

 Autonomous Underwater Vehicles (AUVs), capable of conducting unmanned underwater surveys, have been recognized as a promising technology for enhancing productivity in underwater environments. In this study, we introduced an AUV equipped with a Phase Measuring Bathymetric Sonar (PMBS) for investigating the sedimentation conditions in Lake Horai (Ure Dam), and evaluated its effectiveness from three aspects: Accuracy, Risk Avoidance, and Cost. The comparison of the averaged ground elevation data (mesh data with 1-meter interval) processed by the PMBS, and the Multibeam Echo Sounder (MBES) revealed no significant difference, indicating that the PMBS provides depth measurement accuracy comparable to the MBES. Furthermore, the sedimentation condition survey conducted using the AUV with PMBS not only facilitated the avoidance of inherent risks, such as researchers submerging into water, but also required half the number of survey personnel compared to the MBES survey. This resulted in approximately 50% reduction in labor related to equipment testing and depth measurement, as well as an estimated 60% reduction in associated labor costs.