Air Force Station Yelahanka, Bengaluru

20th (Wed) - 24th(Sun), February 2019

Naval Physical and Oceanographic Laboratory


About Lab

Naval Physical and Oceanographic Laboratory (NPOL), Kochi is a premier R&D establishment of the Defence Research and Development Organization (DRDO), Ministry of Defence, Govt. of India. NPOL is a ‘Systems Laboratory’ of DRDO engaged in the development of SONAR (Sound NAvigation and Ranging) systems and allied technologies. The thrust areas of R&D of the laboratory are Signal processing, Electronics, Engineering systems, Transducers, Materials and Oceanography. The laboratory has developed hull mounted sonars for ships and submarines, towed array sonars and airborne sonars for Indian Navy. NPOL’s work in this area has helped the nation achieve self-reliance in this vital area.

NPOL was established in 1952 as a Naval testing laboratory Indian Naval Physical Laboratory (INPL) in the Naval Base, Kochi. After becoming a part of DRDO, it was shifted to the present campus at Thrikkakara in 1991. The laboratory has its main campus at Thrikkakara also has a test & evaluation facility at Kulamvu, Idukki. The Lab also owns a research vessel called the INS Sagardhwani. It is the only unit of DRDO in the state of Kerala.

NPOL had developed several gadgets for naval and civilian applications in its first two decades, besides providing fleet support for maintenance of equipment. Some of them are Expendable Bathy Thermograph, rail demagnetizer, current meter, sonar ray plotter etc. Subsequently, in the late 70’s, NPOL undertook the path breaking staff project Advanced Panoramic Sonar Hull mounted (APSOH) Sonar. It was the first hull mounted sonar system electronics, which was taken from bread board stage to production at Bharat Electronics Ltd. This paved the way for total indigenisation of ship sonars. This was followed by development of submarine sonars PANCHENDRIYA & PAYAL and also the second generation Frigate sonar HUMSA. The airborne systems like TADPOLE sonobuoy and SIMHIKA sonobuoy processing system and MIHIR dunking sonar were also initiated during this period. The new millennium saw the induction of submarine sonar USHUS, the new generation ship sonars HUMSA-NG, torpedo defence system MAAREECH, and the Low Frequency Dunking Sonar (LFDS) for ASW helicopters. Currently, the laboratory is working on ambitious mission mode projects and technology demonstration projects. The cumulative order book value of products based on NPOL’s technologies today stands at over Rs. 4600 Crores.

Shri. S. Kedarnath Shenoy

Shri. S. Kedarnath Shenoy, OS assumed charge as Director NPOL, Kochi with effect from 1st March 2015. He holds M.Sc Degree in Physics with specialization in Electronics from University of Kerala and M.Tech in Computer Science from IIT, Bombay. He completed the one year Advanced Training Course in Nuclear Science & Engineering at the BARC Training School, Trombay during 1982-83 and joined the Reactor Control Division of the BARC as Scientific Officer – C in 1983 where he worked on the development of a Metallographic Image Analysis System.

He joined the Defence Research and Development Organization (DRDO) in 1984 and was posted to the Naval Physical & Oceanographic Laboratory (NPOL), Kochi as Scientist-B. At NPOL which specializes in developing underwater surveillance and communication systems for the Navy, he has handled various responsibilities as Project Manager, Division Head, Group Head and Project Director. In these capacities he has contributed to a number of projects and technology development programmes such as Action Speed Tactical Trainer, Modular Data Bus, Weapon Computer for the indigenous Light Combat Aircraft-Tejas, Hull Mounted Sonar system – HUMSA-NG for Naval warships, and various other sonar systems & technologies for ship, submarine and airborne platforms. He has also undergone a three months training programme in advanced software engineering methodologies conducted by Carnegie Mellon University and Indus Tech at Pittsburgh, USA during 1986. Before taking over as Director, he served as Associate Director in charge of Electronics Groups leading a team of over 100 scientists & engineers comprising 5 divisions working in various areas of electronics including signal conditioning, power electronics, signal processing and embedded computer hardware & software for Sonar systems. He was also supervising the Hull Mounted Sonar projects of NPOL.

He is a recipient of the VASVIK award in Electronics for the year 1990 for his contributions to the development of an indigenous fiber optic data bus system for warships of the Indian Navy. As Project Director, the team under his leadership was awarded the “DRDO Performance Excellence Award for the year 2010” by the Hon’ble Defence Minister Shri. AK. Antony for the successful development of HUMSA-NG sonar system which is installed on the latest Frigates of the Indian Navy and being fitted on many other Naval Ships, He has also received a number of awards at the laboratory level including the ‘Laboratory Scientist of the Year’ in 2008.



Advanced Panoramic Sonar Hull Mounted (APSOH) was the first SONAR from NPOL that was inducted in to Indian Navy. The induction of the sonar was followed by the commissioning of a training simulator, APSIM at SNC, Kochi. M/s Bharat Electronics was the production agency for the system.

Hull Mounted Sonar Advanced (HUMSA) was the second generation of frigate sonar. HUll Mounted Variable Depth (HUMVAD) sonar is another version of APSOH where the Sonar array depth can be varied for tactical purposes. M/s Bharat Electronics was the production agency for both the systems.



HUMSA-NG is the third generation indigenous, ship borne, hull mounted, Sonar system designed by Naval Physical & Oceanographic Laboratory, DRDO, Kochi and productionised by Bharat Electronics, Bangalore. HUMSA-NG is a state of the art Active cum Passive Integrated Ship Sonar system designed to be installed on a variety of naval surface platforms such as Frigates, Destroyers, ASW Corvettes and other classes of ships.

HUMSA UPGRADE is essentially new sonar with existing sensor array. This sonar has many advanced features in signal acquisition, processing, analysis and display formats. It can detect and classify more targets simultaneously. The hardware is based on latest architecture and total number of cabinets has come down from existing nine to just two and half cabinets. The system comes with advanced features where signatures of many targets can be saved and can be displayed immediately when such targets are detected. The system is equipped with advanced fault finding mechanism where even the cable fault also is detected and displayed. The new system can be integrated with many auxiliary systems like underwater communication, sea bottom profiling unit, radar and many fire control systems. This sonar can identify and track torpedoes fired from other targets.



ABHAY is an advanced active cum passive compact integrated sonar system designed and developed for the smaller platforms such as coastal surveillance/ patrol vessels. It employs advanced adaptive signal and information processing techniques for detection, tracking & classification of targets. The hardware architecture is based on the latest technology that enables smooth up-gradation of the system capabilities. The system architecture is designed to have feature like scalability, ease-of- maintenance & high reliability

It was the first indigenously developed integrated submarine sonar and tactical fire control system designed for Foxtrot class of submarines. The sonar consists of passive surveillance, passive ranging, intercept, active and underwater communication system.



USHUS is a submarine sonar suite designed for the EKM class of submarines. This is a compendium of multiple sensors for passive detection which collates different characteristics of the same target and provides target data through information fusion. The constituent sonars in the suite include passive sonar, active sonar, intercept sonar, obstacle avoidance sonar and underwater telephony.


USHUS-2 is an Integrated Submarine Sonar System which physically and functionally replaces the MGK-400 and MGK-519 Sonars on four EKM class of submarines. USHUS-2 is a state of art upgrade of NPOL designed sonar USHUS in terms of the technology and sonar capabilities. USHUS is operational onboard five of the nine frontline EKM submarines of Indian Navy. USHUS-2 is a world class sonar suite, tailored for the remaining four EKM class of submarines. USHUS-2 sonar suite includes Passive Sonar, Active Sonar, Intercept Sonar, Obstacle Avoidance Sonar and Underwater Telephony. The USHUS-2 Sonar Suite has been designed and developed by NPOL and productionised by M/s. Bharat Electronics. USHUS-2 is currently in installation phase in IN designated platforms.

Payal is a Submarine Sonar System for submarines, comprising of a Passive, Active, Intercept and Underwater Communication System. The original version was a hardware intensive system which was later upgraded with a new compact processing system based on current technology, processing power and new algorithms bringing in better performance, reliability and maintainability.



Advanced Indigenous Distress Sonar System (AIDSS) is a device that can be an add-on fitment on submarines for acting as an emergency beacon. It is distress sonar which pings SOS signals when the submarine is sinking due to any untoward situation. It can be placed in any compartment of the platform and is designed for automatic / manual activation.

Nagan is a towed array sonar system that consists of a transmitter body and a long passive array towed behind the ship. The towed array can be deployed up to 200 m depth. It is useful in Anti-Submarine Warfare (ASW) operations and is the apt sensor for warships to locate silent submarines capable of launching high speed torpedoes.



Advance Light Towed Array Sonar (ALTAS) is state of the art efficient sensing system for the detection, localisation and classification of submarines operating especially in the below sonic layer. It is useful in Anti-Submarine Warfare (ASW) operations and is the apt senor for warships to locate silent submarines capable of launching high speed torpedoes.

It is an Anti-Torpedo Defence System (ATDS) that consists of a sensor array and an interface with the fire control system. Here the sonar is a towed sensor array deployed from a winch. The system detects, tracks and classifies the torpedo and interacts with FCS to control the launch of expendable decoys.



Tadpole is a passive sonobuoy which is deployable from high altitudes. It has a choice of two selectable operating depths and three different operating periods up to 8 hours. It has been productionised through M/s. Tata Power Company Limited, Bengaluru.

MIHIR was a first generation helicopter sonar system, comprising of dunking sonar and a four channel sonobuoy processor. It was designed for Advanced Light Helicopter (ALH) type platform, where weight, space and power are at premium. The development and trials of this system has given considerable insights in the area of winch design and homing operations.



Low Frequency Dunking Sonar is an advanced version of Mihir. The development of an airborne winch for deployment and retrieval of dome is a significant technology leap in this sonar system. LFDS is capable of both active as well as passive sonar operations. It is presently fitted on an Advanced Light Helicopter (ALH).

The sea bed array is an off board sonar meant for passive surveillance of underwater targets. It consists of sets of transducer arrays which are placed on the seabed. The hydrophones pick up the signals of the vessels passing in the vicinity of the array and the data telemetry system ensures transmission of these signals to a ship or shore station. These are further processed, thereby enabling detection, localisation, classification and tracking of the targets.



UWT is a medium power compact system, which provides speech, Morse code, digital data communication between Submarines or between surface vessel and Submarine using water as acoustic medium. The UWT conforms to NATO and EKM standards for Military underwater communication.

The Under Water Acoustic Communication System (UWACS) enables the half duplex communication between submerged and surface platforms through Analog (SSBSC-AM in the NATO and EKM bands) and Digital (CSK, OFDM, FSK modulations) means. In the event of radio silence (in RF bands) during operational requirements, communication between surface platforms also can be done through the same system.



The compact version of 3rd Generation Underwater Wireless Acoustic Communication System (3G UWACS) named as UWACS TRITON, is built on Software Defined Radio (SDR) architecture. This system incorporates advanced modulation and coding techniques in addition to data recording and analysis features.

The Integrated Coastal Surveillance System (ICSS) is a system developed for guarding India’s coastal territory for quick detection, location and monitoring of movements of suspect dhows, motorized and traditional vessels in a given controlled area, round the clock without any physical presence. The system being multidisciplinary in nature, a multi-lab approach was followed with NPOL as the nodal lab for system integration. The participating labs include LRDE, IRDE, DEAL, DLRL and CAIR. The systems being developed include Coastal Surveillance Radar (LRDE), Electro Optical Systems (IRDE), Communication Interception System(DLRL), Automatic Identification & Communication System(DEAL), Harbour Surveillance System (NPOL) and Application Software & Security Solutions (CAIR).



It is a general purpose multiplexed data network designed and developed for the communication needs for a wide variety of naval platforms. It is compatible to IEEE 802.3 (Ethernet). The system consists of three Ethernet coaxial cable data buses interconnecting up to maximum of 32 modular units called the Modular Transput Controllers.

Stores Interface Box (SIB) is the brain of Stores Management System (SMS) for LCA Tejas. It is a VME based open system hardware with inbuilt redundancy having safety interlocks for release and emergency jettison of stores. It integrates stores using weapon bus and provides interface to cockpit through Open Architecture Computer (OAC). It controls Pylon Interface Boxes (PIB) based on high level commands received from OAC over 1553B buses for release/control of stores.




  • Underwater projectors
  • Hydrophones
  • Acoustic baffles
  • Rubber moulded junction boxes
  • Sonar domes


  • Digital Signal Processors
  • Signal Processing Software
  • High-performance Multi-Processor boards


  • Sonar structures
  • Winch and handling systems
  • Electronic enclosures &hermetically sealed units
  • Underwater cables & connectors
  • Computer Aided Engineering


  • MEMS Devices
  • Structural composites
  • Smart materials
  • Functional coatings
  • Damping technologies & encapsulants


  • Sonar Performance Prediction
  • Oceanographic database
  • Underwater acoustic models
  • Benchmarking of sites
  • Experimental oceanography


  • Sonar front-end systems
  • Data acquisition units
  • Telemetry hardware
  • Power supply units
  • Power distribution units


  • Fibre Optic / Optical Hydrophones
  • Vibration/acoustic monitoring devices


  • Detection techniques
  • Estimation algorithms
  • Classifiers


  • Sonar transmitters
  • Power amplifiers
  • Fuel cell power systems


  • Advanced human machine interface
  • Networks/communication/interfacing
  • Display Systems Software Framework


  • Computer-aided simulations
  • Software trainers
  • Physical trainers
  • Sonar simulators

Coming Soon