Technology to ensure maritime safety

Surveillance is an integral part of maritime safety and protection of our waters. Continuing research on technological innovations, including the strategic use of sonar, applications of oceanography, electro-acoustic transducers, signal processing and systems engineering, is of vital importance in keeping our territories secure and forces operations-ready.
An institution engaged in studies and research in this area is the Naval Physical and Oceanographic Laboratory (NPOL).
This functions under the Defence Research and Development Organisation. It was set up in 1952 as an in-house laboratory of the Indian Navy (Indian Naval Physical Laboratory) for providing scientific support to the armed services. In 1958, it assumed its present name. The lab has a bright track-record in sonar research and support to our naval force.
It has developed and delivered various sonar systems, including the Advanced Panoramic Sonar Hull Mounted (APSOH) system, Panchendriya, Humsa and Mihir, which have been fitted to submarines, surface ships, and airborne platforms of the Navy. The NPOL has built up excellent infrastructure for research in the cutting-edge areas of its speciality. Some of these are indicated below.
INS Sagardhwani
INS Sagardhwani is a marine acoustic research vessel, commissioned in 1994. The vessel is being maintained by the Southern Naval Command, Kochi.
This floating laboratory, housed in a 2,000-tonne ship, is equipped with facilities for research in physical and chemical oceanography, marine meteorology, acoustics, geology and geo-acoustics. It records ocean environmental data for analysis, from various locations at the sea.
There are rich facilities like navigational aids including satellite navigator, global positioning system, navigation computer, Decca navigator (a hyperbolic radio navigation system operated by measuring the phase differences between continuous signals from master and slave stations), survey echo sounders, Doppler speed log, navigational radar, gyro compass, multi-beam echo sounder, sub-bottom profiler, acoustic Doppler current profiler and ship-borne wave recorder.
Underwater acoustics
A laboratory at a lake at Kulamavu, 100 km from Kochi, is used for calibrating and full-scale testing of underwater acoustic transducers, arrays, and other sub-sea equipment such as fish-finding sonars, echo sounders, velocimeters, underwater communication systems and decoys.
Acoustic test facility
This is a giant acoustic tank measuring 50x20x18m, equipped with a 10-tonne remote-controlled electric overhead travelling crane. There are precision transducers and other equipment that can measure very low frequencies as well.
Simulated test facility
This is a very rare facility even at the global level. It can carry out any static or dynamic measurement, evaluation and calibration of any material or sensors and transducers for undersea use.
It is used for studies in oceanography, ocean acoustics, marine geophysics, underwater acoustic transducers and undersea equipment, including underwater cameras.
The Distributed Control System, the brain behind the facility, performs functions such as automatic process control, data acquisition, display, data storage and retrieval, trend display over long periods, alarm enunciation and fault display.
Darpan
Darpan is a state-of-the-art cluster computing facility that provides system-level simulation of the sonar systems and its environment.
MEMS Research Facility
For manufacturing MEMS (Micro-Electro-Mechanical Systems), nano-devices and micro circuits, the NPOL has a clean room of Class1000. Assembly and testing of precision electronic assembly are also carried out in this facility.
(A clean room has a highly purified and regulated atmosphere, with very few airborne particles.
It is generally used for manufacture of delicate items such as microprocessors, using a strict protocol. A Class1000 clean room has no more than 1,000 particles larger than 0.5 microns in a cubic foot of air.)
Prototype manufacturing
The laboratory has the latest machinery including CNC machines for engineering operations for its projects. The facility has equipment for high-precision machining and finishing jobs. Services of specially trained manpower are also available.
CIEDA
The Centre for Integrated Engineering Design and Analysis (CIEDA) is equipped with 3D modelling software, meshing software and sophisticated engineering analysis tools.
Virtual prototyping centre
This centre creates virtual prototypes of sonar systems that are developed at the NPOL. State-of-the-art hardware and high-end software capable of generating 3D virtual models are available for such creation. Animation and e-documentation can be carried out in this centre.
Oceanics
The Centre for Oceanics and Optronics works in the field of optics for hydrophones and non-acoustic technology.
It has a photonics lab where in laser-based sensors are developed. A fluid dynamics laboratory in the centre can simulate the ocean conditions for studying the internal waves generated by underwater moving targets.
Towed array centre
Towed arrays can be used to detect ships, submarine, or marine life. They have military applications. The node points of the acoustic array receive acoustic energy. The acoustic energy may be from the object detected. Alternatively, it may be a reflected signal.
A towed array may comprise a rubber hose four inches in diameter and several miles long.
It may be towed by a submarine.
The hose contains thousands of transducers and a coaxial cable and tele-metering equipment for transmitting electric signals caused by the transduced acoustic energy. Towed array sonars are important sensors used by submarines. Unlike active sonars, towed arrays do not betray the location or identity of the user.
The assembly of towed array is a highly complex process which involves environmental stress screening of electronic components, testing of acoustic and engineering sensors, wiring of array, tube insertion, oil filling and final assembly of various modules for trials.
Source: The Hindu