Research Projects
SEI has undertaken several research projects funded by the National Defense Center of Excellence for Research in Ocean Sciences (CEROS). The mission of CEROS is to advance innovative concepts and new approaches to technology while fully leveraging existing facilities and infrastructure in Hawaii and demonstrating beneficial commercial utility of the Department of Defense. Since the initiation of CEROS in 1993, SEI has received 5 grants.
Completed CEROS grants
Development of a Broadband FM Sub-bottom Profiler for Seafloor Imaging and Sediment Classification (1996) (Imaging Examples)
This project was a joint effort of SEI and Precision Signal Inc. of Florida to develop a sub-bottom profiler for imaging and mapping seafloor structure in Hawai`i and other Pacific Islands. The project resulted from a need to map offshore sand resources for beach nourishment and the construction industry. At that time, no profiler was able to adequately image Hawaii's calcareous sands. The result was the successful development and testing of the most technologically advanced high-resolution sub-bottom profiler currently available. The profiler transmits pulses over the frequency range of 300 to 10,000 Hz, depending on the resolution and penetration needs of the projects. Specific project tasks included collecting Hawai`i sand deposit data for system definition and testing, designing sonar hardware and signal processing, constructing the sub-bottom profiler, and field testing the system. Please look at our Publications for additional information on the Sub-bottom Profiler.
Development of a Technique to Identify Pollutant Sources and Impacts in Coastal and Oceanic Waters (1996)
This was a joint project of SEI and the California Institute of Technology to develop ICP-MS (inductively coupled plasma mass spectrometry) as a new method to measure coastal pollution. The objective of the study was to develop sampling and analysis techniques that would be applied to fully saline coastal waters. The year-long study involved sampling from three discharge sources (the Pearl Harbor Watershed, the Wai`anae sewage treatment plant, and Inoa`ole Stream in Waimanalo); sampling of the receiving waters; ICP-MS analysis of the water samples; determination of the presence of unique spectral fingerprints for the discharge sources; analysis of the temporal variations of the spectral fingerprints; and evaluation of the applicability of the ICP-MS method to oceanic and coastal waters.
Ongoing Projects at SEI
Development of a 3-D
imensional High Resolution Buried Object Imaging System (Imaging Examples)Sea Engineering and Precision Signal of Boca Raton, Florida are developing a forward/aft - port/starboard sweeping, high resolution buried object imaging sonar for locating and imaging small objects buried beneath the seafloor. The first year of work involved designing and constructing the 32 channel sonar, collecting raw acoustic data over buried objects, and processing the data offline to determine the best processing techniques. The selected design operates over a frequency range of 5 to 25kHz, and consists of 6 transmitters, a 32 element receive array arranged in 8 line arrays of 4 elements each, housed in a 300 pound tow vehicle. Tests have been conducted at a controlled test range established at Makai Pier. Results of the tests indicate that a beam steering angle of 12 degrees is most effective for imaging the buried objects. The images have been processed using filtering and thresholding techniques, and a 3D image of a buried target has been developed. Additional work will entail implementing the processing techniques tested in real time to allow locating and classifying buried objects at sea.
Development of an Ultra-High Resolution Stress Detection System for Marine Application
Research work at the University of Hawaii has shown that stress in metals can be detected with great sensitivity by measuring the power spectrum associated with low frequency voltage fluctuations within the material. The goal of this project is to use this scientific phenomena to develop technology for highly accurate detection of stress in materials used in the marine environment.
MultiSpec Corporation Advanced Signal Processing
This project is developing advanced signal processing techniques which will enhance the resolution capabilities of sonar systems and data. The work will test a new processing technique originally developed by MultiSpec Corporation for synthetic aperture radar (SAR), that can improve resolution strictly through processing of the received raw phase data without increasing the physical bandwidth of the transmitted pulse and without increasing the computational effort. This enhanced resolution filter (ERF) will be tested on sonar data collected by Sea Engineering. Successful enhancement of the sonar data could result in resolving finer sedimentary stratigraphy, elimination of acoustic artifacts, better location and identification of buried objects, and more accurate classification of sediments.
Please contact Sea Engineering, Inc. for any additional information.