Technology Projects > Coastal Environmental & Engineering > Activities

Marine Sensor Systems Activities


The activities of Marine Sensor Systems group is mainly focused on indigenous development of sensors, acoustic transducers and systems for underwater applications, underwater acoustic imaging, etc. Further to the successful development of Buried Object Scanning Sonar Phase-I, currently the group is focussed on the following acoustic imaging programs as per the recommendations of PRB and SAC.
Development of 2D/3D subsea bed imaging sonar
Development of Indigenous Side Scan Synthetic Aperture Sonar

Progress
For both the above mentioned new projects, Preliminary Design Documents have been prepared after extensive literature survey. Preliminary Design Review also has been carried out.

Development of 2D/3D Sub Sea Bed Imaging Sonar:

  • The objective of the project is to design and develop Acoustic Imaging Sonar which can generate 2D/3D images of sub seabed objects such as pipelines, ordnance and archaeological objects. For realisation of 2D/3D imaging, Mills Cross Array Configuration has been proposed. The system will have the capability of imaging subsea bed objects in both XY (across track) and XZ (depth profile) directions. System is aimed at imaging the objects with decimetre level resolution. For operational height of 10m from the seabed, the across track swath coverage of the system will be about 10 m for ±25° beam steering. The system will be initially realized using surface tow body and final system will be integrated with submerged tow body/AUV.
  • An appropriate design is being finalized and Critical Design Review (CDR) is also proposed in due course. Wideband Beam forming, Angular Motion Correction, Synthetic Aperture Sonar Processing and Image Enhancement techniques have been initiated as part of realisation of the project.

Development of Side Scan Synthetic Aperture Sonar:

  • The objective of the project is to design and develop side scan synthetic aperture sonar which can provide high resolution images (decimeter level) of the sea bed and objects with range independent resolution. An additional objective of the project is to attempt interferometric technique to get the height information of objects. The design frequency is chosen as 85-100 kHz.
  • The sonar is aimed for shallow water applications with an operational height of ~10m from the sea bottom and operational depth of ~5-10 m from the sea surface, with swath coverage of ~100m at each side. The system is aimed to be integrated in platforms with a tow speed of at least 4 knots. Initially for preliminary tests and concept proof, a tow fish will be used as the sonar platform.
  • To achieve the required resolution and tow speed, Vernier technique based design is carried out for the transducer array. The dimension and number of elements of the required transducer array to achieve the objectives are worked out.
  • The overall system architecture of the sonar is also designed by considering the signal generation, acquisition, data transmission, navigation and motion compensation requirements. Motion compensation and signal processing methods are also identified. As suggested by the preliminary design committee, critical design with finer details of the subsystems is being carried out.

Design of suitable platforms for the proposed imaging sonar systems:
Literature survey is being carried out to design suitable tow fish for both imaging sonar systems. Platform will be finalized after completion of CDR for the above two projects.

  • Identified areas of cooperation from national, international organizations to fill the gap
  • Development of advanced underwater acoustic signal processing techniques/systems/algorithms.

National

  • The group is continuing the interaction with Bharat Electronics Ltd, (BEL) Bangalore for transforming laboratory prototype from the group to Product level. An existing MoU with BEL is proposed to be extended from February 2019 to another three years till 2022.
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  •  International Collaboration
  • Initiated interactions with University of Plymouth (UoP) as a continuation of the visit of Minister of S&T, UK to NIOT on 27th July, 2018.  A draft MoU has been sent to University of Plymouth (UOP), UK on Research and Technology Development in the areas of Marine Sensors, Underwater Instrumentation and Miniaturized Marine sonar systems for light and compact vehicles in shallow water applications with the approval from GC for concurrence.
  • Initiated interactions with Tropical Marine Science Institute (TMSI), National   University of Singapore (NUS) for collaborations in the following areas with the approval of GC. Acoustic Sensor (Transducers/Hydrophones) technology enhancement for acoustic imaging, Underwater signal processing, digital hardware, data analysis, specific algorithm development or utilization of already developed algorithms by Acoustic Research Laboratory (ARL) as an exchange program.
  • The proposal envisages manpower training and conducting experiments in Indian/Singapore waters which are mutually beneficial.
  • A draft MoU has been prepared, and sent to NUS. NUS is considering the proposal.
  • Indo French thematic Workshop for Academia- Industry Partnership on Marine Sciences by Indo French Embassy on 2nd February 2019 at Kochi, Kerala. Initially, French delegation visited NIOT and had presentations during 1st week of April 2018.
  • Dr.Dhilsha Rajapan, GH, MSS participated in the “New Marine Technologies (Sensors, microprocessors, data processing..)” workshop  for the identification of potential R&D collaboration between the two countries as an intergovernmental program. Four areas which are of mutual interest of NIOT are identified during the workshop.
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Summary

Preliminary design documents for the development of 2D/3D subsea bed imaging sonar and Indigenous Synthetic Aperture Side Scan Sonar have been prepared. Preliminary design reviews for both the projects are carried out. Currently as suggested by the preliminary design review committee, critical design with finer details of the subsystems is initiated.