Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Chunhui Xu Asada, A. Abukawa, K. |
| Copyright Year | 2011 |
| Description | Author affiliation: Doctor Course, Asada Lab, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan (Abukawa, K.) || Institute of Industrial Science, The University of Tokyo 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan (Asada, A.) || Master Course, Asada Lab, Graduate School of Frontier Sciences, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan (Chunhui Xu) |
| Abstract | DIDSON is a highly definition sonar which uses acoustic lenses to make images in dark, turbid waters where optical systems are ineffective. The acoustic lenses of it focus and form an acoustic image on the transducer array at the rear of the sonar. Then electronics convert that acoustic image into a digital image which can be displayed on a computer screen. The combination of high frequency sound waves, acoustic lens configuration, and high resolution transducer array make it suitable for different kinds of applications such as: positive identification and inspection, navigation in close quarters, monitoring in turbines or being used as a security video camera underwater in dark and turbid conditions etc. However, the images formed by DIDSON are a little bit different from the images generated by Optical video cameras. Sometimes, it is high demanding for users to analyze the DIDSON data. In order to make the images being understand much more easily, one method is to improve the algorithm which was being used in the conversion of acoustic images. We used the standard DIDSON to take the video of the water column at several spots in the Yamanaka Lake, Japan. Considering with the depth of lake, we chose the high frequency sound waves (1.8 MHz) which consists of 96 beams, each beam spanning 0.3 degrees in the horizontal plane. Aimed to work out the whole 3D image of the aquatic plants, we set acoustic beam projections of DIDSON towards the bottom of the lake and turned it 45 degrees up from vertical. By doing that, echoes came back from aquatic plants were began with the root and ended with the top of the aquatic plants. Also, we added a concentrator lens which reduces the vertical aperture from 14 to 1 degree in front of the DIDSON. Therefore, each beam pattern is consisting of 96 beams covering a 30 deg by 1 deg spread. It allowed horizontal DIDSON beams to go farther in the water with reduced surface and bottom reverberation and illuminates thin slices which were very useful in 3D reconstruction of the growth condition of aquatic plants. In this study, we designed a new system for the detection of aquatic plants with suitable equipments which can be widely used in surveys of underwater ecological reserves. We also developed a software which can generate 3D views of the aquatic plants in accuracy of 1 centimeter. For future work, we hope to apply it into the identification of aquatic plants species. |
| Starting Page | 1 |
| Ending Page | 5 |
| File Size | 478846 |
| Page Count | 5 |
| File Format | |
| ISBN | 9781457701658 |
| e-ISBN | 9781457701641 |
| DOI | 10.1109/UT.2011.5774148 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2011-04-05 |
| Publisher Place | Japan |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | Acoustics Acoustic beams Three dimensional displays Lenses Pixel Sonar Optical imaging |
| Content Type | Text |
| Resource Type | Article |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|