Exploring the Feasibility of Affordable Sonar Technology: Object Detection in Underwater Environments Using the Ping 360

Abstract

This study explores the potential of the Ping 360 sonar device, primarily used for navigation, in detecting complex underwater obstacles. The key motivation behind this research is the device's affordability and open-source nature, offering a cost-effective alternative to more expensive imaging sonar systems. The investigation focuses on understanding the behaviour of the Ping 360 in controlled environments and assessing its suitability for object detection, particularly in scenarios where human operators are unavailable for inspecting offshore structures in shallow waters. Through a series of carefully designed experiments, we examined the effects of surface reflections and object shadows in shallow underwater environments. Additionally, we developed a manually annotated sonar image dataset to train a U-Net segmentation model. Our findings indicate that while the Ping 360 sonar demonstrates potential in simpler settings, its performance is limited in more cluttered or reflective environments unless extensive data pre-processing and annotation are applied. To our knowledge, this is the first study to evaluate the Ping 360's capabilities for complex object detection. By investigating the feasibility of low-cost sonar devices, this research provides valuable insights into their limitations and potential for future AI-based interpretation, marking a unique contribution to the field.

Figures (4)

• Figure 1: (a) Experimental set up of the small pool, (b) used objects for sonar scan
• Figure 2: (a) Illustration of the sonar sensor positioned at 0° horizontal, with its transducer head aligned along the x-axis. The expected vertical and horizontal coverage of the transmitted pulse is also shownHP12, along with the scan area (represented by the blue rectangular box) in a hypothetical tank; (b)Raw sonar output data from a 102° scan of an empty tank with a boundary at approximately 1.50 meters. The left axis shows the intensity values (I) ranging from 0 to 255 in a polar coordinate system; (c) Converted polar representation of the raw data in (b), where the tank boundary is visible at 1.50 meters. This form is typically displayed by the sonar interface software and is commonly used in AI algorithm-driven research for sonar data analysis. All figures are shown for demonstration purposes.
• Figure 3: Experimental setup pictures and corresponding Ping 360 software - ping viewer processed polar occupancy map of the collected data
• Figure 5: Experimental set up of experiment 1, and enhanced polar occupancy map