You are here

Integrated Optical Imaging of the Environment on Underwater Autonomous Vehicles


OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Trusted AI and Autonomy OBJECTIVE: Advance integration of camera imagery collection and onboard processing for environmental sensing on low-power, long-duration oceanic gliders and/or profiling floats. The system should allow for two-way communication between the sensor and platform microcontrollers; and software architecture should be tunable to specific parameters, e.g., adaptive capability to turn on imagery collection at target locations or times (e.g., within a set distance from the surface or bottom). Onboard processing and file reduction should allow for near-realtime data delivery of select low-resolution imagery and/or analysis products from imagery via satellite comms (iridium, Starlink, etc.). DESCRIPTION: Long-endurance profiling floats and gliders are critical components of today’s ocean environmental monitoring systems with standard sensor payloads sampling scalar fields (e.g., temperature, salinity, fluorescence). These platforms, which are available as off-the-shelf units or manufactured in house at academic institutions, can be modified to carry additional specialized sensors. Such efforts are often targeted to a specific science need, but are rarely fully integrated with the platform, and exist primarily as one-off prototypes. The field of underwater optical imaging has a long history with significant recent advances afforded by continued development of low-cost, high-performance sensors and computational capabilities for onboard processing [Ref 1]. Recent developments have included optical sensing packages with low-power and small space requirements making them suitable for integration on long-endurance platforms [Ref 2]. The Navy seeks a fully integrated, low-power optical imaging system on long-endurance (~6 month mission capability) profiling platforms. While all components—the platform, optical sensing packages, and compression/analysis software—are available in some form as commercial off-the-shelf systems; integrated systems that allow for real-time delivery of compressed information are in their infancy. Additionally, most optical imaging systems appropriate for use on small displacement vehicles target imaging of plankton [Ref 3]. This STTR topic seeks a design capable of imaging both the near-field (order 1 cm) and mid-field (order 1 m) of view, with camera sensors capable of resolving both millimeter- and meter-scale objects. The system can consider either passive or active imaging techniques optimized for the euphotic zone. Imaging should extend both below and above the surface with potential sensing targets: relative motion of marine snow and particulates, near-surface bubble concentration, above-surface environmental conditions (e.g., films, white-capping). Critically, the design must be integrated allowing for adaptive sampling with the sensor package and include onboard processing capable of providing near-realtime data delivery of select low-resolution imagery and/or analysis products from imagery via satellite comms (iridium, Starlink, etc.). PHASE I: Identify hardware components that can meet the stated requirements. Develop a concept for onboard software, including analysis of bandwidth and data transfer constraints. Develop a design concept for the integrated optical imaging system. Analyze for strengths and weaknesses of the proposed design. Develop a design review to be conducted in Phase II. PHASE II: Develop and test a prototype system. Complete an analysis of the performance of the system and report on the results. Conduct multi-stage testing allowing for redesign between tests with initial tests in a surrogate ocean environment (e.g., lake or tank), interim test in the ocean under controlled conditions (e.g., coastal bay), and final test in the field under a range of environmental conditions. Develop and test both hardware and software systems. The final prototype should include a fully integrated sensing package capable of adaptive sampling and delivery of data via satellite. Analyze and report on the strengths and weaknesses of the final design based on results of the field tests. PHASE III DUAL USE APPLICATIONS: The developed technology has potential use in any DoD, civil, or commercial application that requires detailed information on the ocean environment as certain elements, like the presence of marine vegetation or surface slicks/films, are not easily sensed through other means. Field testing in Phase II will constrain the parameter space under which the system is operationally capable for the Navy. Other potential use sectors include the oil and gas industry (e.g., tracking of spills under ice), and state/federal marine life monitoring agencies (e.g., NOAA Fisheries Monitoring and Analysis Division). REFERENCES: 1. J. S. Jaffe, "Underwater Optical Imaging: The Past, the Present, and the Prospects," in IEEE Journal of Oceanic Engineering, vol. 40, no. 3, pp. 683-700, July 2015, doi: 10.1109/JOE.2014.2350751. 2. Picheral, M., Catalano, C., Brousseau, D., Claustre, H., Coppola, L., Leymarie, E., Coindat, J., Dias, F., Fevre, S., Guidi, L., Irisson, J.O., Legendre, L., Lombard, F., Mortier, L., Penkerch, C., Rogge, A., Schmechtig, C., Thibault, S., Tixier, T., Waite, A. and Stemmann, L. (2022), The Underwater Vision Profiler 6: an imaging sensor of particle size spectra and plankton, for autonomous and cabled platforms. Limnol Oceanogr Methods, 20: 115-129. 3. Ohman, Mark D., et al. "Zooglider: an autonomous vehicle for optical and acoustic sensing of zooplankton." Limnology and Oceanography: Methods 17.1 (2019): 69-86. KEYWORDS: optical imaging, underwater autonomous vehicles, ocean gliders
US Flag An Official Website of the United States Government