Wikipedia
USHUS (sonar)
USHUS is an integrated sonar system developed by the Naval Physical and Oceanographic Laboratory (NPOL) of the Defence Research and Development Organisation (DRDO), India, for use in submarines of the Indian Navy. It is primarily designed to be used in Sindhughosh class submarines, though it is reported to be fitted in the Arihant-class nuclear-powered ballistic missile submarines as well. USHUS is reported to be superior to its Russian equivalents.