November 18, 2016

The Indian Navy has formally received four sonars developed by the Indian government’s Defence Research and Development Organisation.

Chief of the Naval Staff Admiral Sunil Lanba was presented with four different sonar systems used for various platforms.

The systems included Abhay – a compact hull mounted sonar for shallow water craft, Humsa UG – an upgrade for the Humsa sonar system, Nacs – a near-field acoustic characterization system, and Aidss – an advanced indigenous distress sonar system for submarines.

The systems have been designed and developed by NPOL, a Kochi based laboratory of DRDO which has experience in the design of sonar systems for the Indian Navy.

Abhay is an active-cum-passive integrated sonar system designed and developed for the smaller platforms such as shallow water crafts and coastal surveillance/patrol vessels. According to DRDO, the sonar is capable of detecting, localizing, classifying and tracking sub-surface and surface targets in both its active and passive modes of operation.

An Abhay prototype was earlier installed on a navy ship and has successfully completed all user evaluation trials to demonstrate the features as per the navy requirements.

The Indian Navy has proposed to induct this sonar on three of the Abhay-class corvettes.

Another system, the Nacs, determines the in-situ performance of the sonar systems which are used to find the frequency-dependent 3-D transmission and reception characteristics of the sonar. It is also used to measure the magnitude and phase characteristics of the sonar transmission and reception electronics and the transducers. The Nacs has been integrated with the Humsa-NG sonar array and proved onboard naval platforms and this will be fitted on all frontline ships.

NPOL has also developed Aidss, a distress sonar that is an emergency sound signaling device which is used to indicate that a submarine is in distress and enable quick rescue and salvage. It is a life-saving alarm system designed to transmit sonar signals of a pre-designated frequency and pulse shape in an emergency situation from a submarine for long period, so as to attract the attention of passive sonars of ships or submarines in the vicinity and all types of standard rescue vessels in operation.