MRI-R2: Acquisition of a Networked AUV-based Instrument for the Southern California Bight

University Of Southern California, Los Angeles CA

Investigators

Abstract

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." Proposal #: 09-60163 PI(s): Sukhatme, Gaurav; Caron, David A.; Edwards, Katrina J.; Jones, Burton, H; Mitra, Urbashi Institution: University of Southern California Title: MRI-R2: Acq. of a Networked AUV-based Instrument for the Southern California Bight Project Proposed: This project, acquiring a networked instrument composed of two complementary Autonomous Underwater Vehicles (AUVs), supports an extensive program of research in robotics, underwater acoustic communication and networking, marine biology, oceanography, and biogeochemistry at the Center for Integrated Networked Aquatic PlatformS (CINAPS). These two AUVs add capability to those already in use by CINAPS. The work addresses two current key limitations: limited depth (depth no greater than 200m) and limited communication (only supports communication through the air, i.e., when the vehicles are not below the surface.) These instruments impact agendas in two main fields: research in the Southern California coastal marine ecosystem (in physical oceanography, geobiological oceanography, and microbial ecology), and research in robotics, communication, and networking. The instrumentation consists of a Slocum Electric Glider and an EcoMapper-EP (Expandable Payload) Autonomous Underwater Vehicle. The Slocum glider, for use up to 1000m, was developed by in the early 1990's, and has become an integral tool of ocean science in this decade. It is driven entirely by a variable buoyancy system rather than active propulsion. The glider's wings convert the buoyancy-dependent vertical motion into forward velocity. Slocum gliders are truly autonomous, requiring a surface vessel only for deployment and recovery. On-board communications capabilities include a two-way RF modem, Iridium satellite and an ARGOS locator. With its onboard instrumentation, combined with its mobility and long-range capabilities, the glider provides continuous, near-real-time information, about the physics and biogeochemistry of the ocean. Designed specifically for water quality and bathymetry mapping applications, the Ecomapper for shallow use (up to 200m) is a unique AUV. Easily deployed by one person, it is able to perform a wide-area survey without a surface workboat or associated personnel. The EP class EcoMapper allows for additional ports for customized sensor integration and space for a second low-power CPU to support the additional sensors and software. This additional CPU enables mission adaptations to occur on-the-fly based on real-time sensor readings that are necessary when trying to detect and track dynamically changing oceanic features a range of important processes and associated questions can only be studied with the coupling of deep AUV operations (up to 1000m) with shallow (up to 200m). These include (a) the toxic effect of harmful algal blooms at greater depth, (b) the temporal and spatial variations of the low oxygen interface (deep basins can become hypoxic or anoxic due to isolation), and (c) fluxes of particulate material from urban runoff to the deeper sea that are discontinuous in both time and space; the spatial extent of which can be best resolved with autonomous vehicles that can maintain a presence over several events. To enable these studies, new algorithms for multi-AUV communication and control are necessary. The ability to coordinate vehicle trajectories and missions while submerged presents a current limitation. This is of particular concern in the Southern California Bight, the study site, a region with high maritime traffic where surfacing of the AUVs needs to be minimized. Used as a field instrument deployed in the Southern California Bight (SCB), the instrument is programmed and bench-tested in the Robotic Embedded Systems Laboratory on the USC main campus in LA. The instrument manager is supported by the PI;s grants. USC covers all operational and maintenance costs. Broader Impacts: The instrumentation impacts faculty research and student education, contributing to enable new science in diverse research projects and impacting the ongoing instruction at the institution and serves as a learning tool to develop student scientific proficiency (through existing courses and participation in faculty-led research). This acquisition plays an important role in the Southern California Bight Study planned for Spring 2010, coordinated by the Southern California Coastal Water Research Project (SCCWRP), a public agency focusing on the coastal ecosystems of Southern California. The PIs have close collaborative ties to this agency. Moreover, the networked and adaptive sensor systems provide important data relating to the climate and health of Southern California coastal ocean. Undergraduate students are involved through REU site awards at USC. Since the PI runs the USC Computer Science department REU site for research in various areas of computer science, students in his lab often assist with data analysis and programming for the robotic boats. The EcoMapper vehicle, which is designed to be portable and deployable in shallow water, is particularly suitable for the next generation of REU students. Other PIs participate as faculty mentors in USC biochemistry REU site encouraging similar participation from undergraduate students in biology.