Source: Navies of friendly countries keen on Indian sonars - The Hindu India is looking to export indigenously developed hull-mounted sonars and negotiations are at an advanced stage with the navies of three to four friendly nations. SONAR (an acronym for Sound Navigation and Ranging) is used to detect underwater targets. Like radar, used to detect long-range aerial and other targets, sonars have applications in underwater surveillance, communication and marine navigation. Three units of these sonars have been exported to Myanmar. Officials from Bharat Electronics Limited and the Naval Physical and Oceanographic Laboratory visited the neighbouring country and installed them a fortnight ago. BEL produced the sonars while the Kochi-based NPOL, a naval lab of the Defence Research and Development Organisation (DRDO), designed and developed them. BEL had signed the Rs.150-crore contract for the three sonars with Myanmar in January 2013. Director-General of DRDO (Naval Systems and Materials) Bhujanga Rao told The Hindu that there was a demand from other nations too. Naval officials from three to four countries came to India and held discussions. Mentioning different sonars developed for the Navy, he said that a versatile, new-generation system USHUS has been installed on Indiaâ€™s first indigenous nuclear-powered submarine, Arihant. It has a higher range and can withstand high static pressure of water. Observing that it was superior to Russian equivalents and comparable to the best in the world, he said that sonars on all Russian-class submarines being operated by the Indian Navy would be replaced with USHUS. Another advanced hull-mounted sonar HUMSA-NG (new generation) was also developed and the Navy had placed orders for its installation on different platforms such as destroyers, frigates and corvettes, Dr. Rao said. A sonar for detecting intruders like divers had been developed for installation at harbour entry points and to protect offshore installations. It will be ready for deployment in a year. Similarly, ship-towed array sonar technology that could detect targets up to 100 km was ready for user-evaluation trials. ABHAY, a compact sonar for fitting on warships of smaller size or shallow watercraft, was currently undergoing technical trials on board INS Ajay, Dr. Rao said.