Distributed Sensing Collective to Capture 3D Soundscapes
Abstract:
Oceans are drivers of global climate; they are home to some of our most important and diverse ecosystems; and they provide a substantial amount to the world’s economy as a major source of food and employment. Sound plays a vital role in the ocean ecosystem, as many organisms rely on the acoustic environment for navigation, communication, detecting predators and finding food. Therefore, the 3D underwater soundscape, i.e., the combination of sounds present in the immersive underwater environment, is of extreme importance to ultimately understanding and protecting underwater ecosystems. Currently, the role and function of underwater sounds are poorly understood, especially in the spatio-temporal reference frame that is most relevant to ocean organisms, largely due to the lack of sensing systems that can provide the necessary spatial and temporal sampling density.
This project proposes a transformative new distributed sampling system to study the underwater soundscape at revolutionary spatial (~100 meters) and temporal (~100 seconds) resolutions that is also simultaneously resolves the small-scale ocean current flow. This breakthrough is achieved by deploying a distributed collective of small hydrophone-equipped subsurface drifters. Group management techniques and coherent sensor data fusion are being developed for this collective of vehicles with uncontrollable motion. The aim is to minimize (ideally eliminate) the use of acoustic infrastructure-to- vehicle communication; instead the correlations imposed by the ambient soundscape must be leveraged to track the drifters. This raises a slew of cyber related challenges that are tightly interwoven with the science applications of the technology. Initial at-sea deployments were used to validate the system operation and to generate soundscape data sets to be used in algorithm development and simulations.
The resources of the project are also leveraged in various outreach activities. Undergraduates were engaged through REUs as well as the PIs Engineers for Exploration (E4E) program, a highly problem-driven program that empowers students to spearhead real-world engineering challenges that impact the world of exploration and resource preservation. Relevant materials were also incorporated into COSMOS, the California State Summer School for Mathematics and Science, a four week STEM summer program for high school students.