A Study of the Depth of the Channel Using a Low-Cost GNSS Receiver Built into a Fish Finder Sounder Case Study of Songkhla Lake, Songkhla Province

Abstract

A bathymetric survey of the marine channel depth is crucial as the channel is constantly undergoing changes due to the sedimentation caused by human activities and natural processes. The accumulation of sediment in the channel leads to variations in its depth, making navigation and docking of ships in the area potentially hazardous. However, the cost of hydrographic surveying tools and equipment is relatively high due to the specialized nature of the technology. In this study, we propose a cost-effective method for conducting thorough water depth sounding and sediment location determination by utilizing a low-cost satellite receiver integrated with the Echo Sounder, which is widely accepted among sailors. The proposed method will be applied at Songkhla Lake, which is a multi-water region with three distinct water types: freshwater, brackish water, and mixed saltwater. Additionally, the vertical values obtained by the water meter and echo-sounding methods will be compared in areas with different water types, to evaluate the accuracy of the proposed method. Studies have shown that the water type does not affect the vertical accuracy obtained by a fish finder sounder. Furthermore, the vertical values obtained from the echo sounder can be applied to the dredging of coastal channels and maintenance, as well as leveling.