An open-source Autonomous Surface Vehicle for Acoustic Tracking, Bathymetric and Photogrammetric Surveys

TL;DR

The paper addresses the barrier of high-cost autonomous surface vehicles by introducing Plancha, an open-source, low-cost ASV designed for multi-modal coastal surveys. It combines a paddleboard hull, a four-hydrophone SBL system, a single-beam echosounder, and a GoPro-based photogrammetry workflow, all orchestrated by a Pixhawk rover autopilot, a Raspberry Pi companion computer, and RTK GNSS for precise positioning. The authors provide an end-to-end replication package including a BOM, mounting instructions, software, and field-validation across autonomous acoustic tracking, shallow-water bathymetry, and photogrammetry, with credible demonstrations such as dense 49 m × 115 m bathymetric grids and 3D reef reconstructions. This open, modular platform enables researchers to conduct fine-scale ecological and environmental surveys in shallow coastal waters at substantially lower cost and complexity, while acknowledging limitations in rough seas and visibility-dependent imaging.

Abstract

Autonomous Surface Vehicles (ASV) are becoming more affordable and include a wide variety of sensors and capacities with applications from ocean physics such as the Saildrone project to ecology with the tracking of marine species in the wild. Here, we present a multi-modal, affordable, open source, and reproducible ASV to track marine animal in shallow waters, collect information on bathymetry, and carry out photogrammetry surveys. The current specification enables scientists to track an animal equipped with an acoustic tag for 5~h and a spatial accuracy of 1~m. For bathymetric or photogrammetry surveys, the ASV can cover 100 x 100~m areas in 2~h with a distance of 1-m between transects. Depending on the sensors included in the ASV, it has a price ranging from \$2,434 to \$11,072. We illustrate these developments with a case study and a field survey for each of the different application proposed.

Figures (10)

• Figure 1: Schematic of the functioning of the $Plancha$ autonomous surface vehicle (ASV) and the data collected during an ASV survey: Autonomous acoustic tracking, single-beam bathymetric survey, and photogrammetric survey
• Figure 2: ASV photos for the different modes: (a) Survey mode for bathymetric and photogrammetric data collection and (b) acoustic mode for animal tracking with the four arms equiped with hydrophones.
• Figure 3: ASV high level electrical diagram and electrical circuit. On the left (A), the corresponding numbers and names of the main parts. The colored names correspond to different wires on the electrical diagram. In the middle (B), the high level electrical diagram with main components and wiring. On the right (C), the electrical circuit with the corresponding numbers. Some components are fixed on the top of the case or outside and thus are not visible on this photo.
• Figure 4: Network diagram of the ASV showing how the autopilot gets and interacts the difference sources of information to perform the navigation of the ASV
• Figure 5: Screenshot of Mission Planner during a navigation test in Saint-Gilles les Bains (Reunion island). The yellow boat shape corresponds to the ASV position. Purple line is its actual track and the green dots are positions where an external signal is sent to control a camera.