India and Australia have launched a joint research project aimed at bolstering undersea surveillance capabilities, marking a significant step in strengthening maritime domain awareness and defense cooperation between the two nations. The three-year initiative, announced on July 3, 2025, involves collaboration between Australia's Defence Science and Technology Group (DSTG) and India's Defence Research and Development Organisation (DRDO), specifically its Naval Physical and Oceanographic Laboratory (NPOL) in Kochi.

The primary focus of the project is to develop advanced techniques for detecting and tracking submarines and autonomous underwater vehicles (AUVs). This collaboration aligns with the Quad's strategic objectives to enhance maritime security in the Indo-Pacific region, particularly in response to increasing submarine activity and regional geopolitical tensions. The project leverages Towed Array Target Motion Analysis (TMA), a sophisticated technology that employs a linear array of hydrophones towed behind a vessel to capture acoustic signals. These signals are then processed using advanced algorithms to estimate the position, course, and speed of underwater targets with high precision, even in noisy environments.

Amanda Bessell, Discipline Leader at DSTG's Information Sciences Division, emphasized that Target Motion Analysis is crucial for maintaining platform situational awareness in passive operations. DSTG Senior Researcher Sanjeev Arulampalam explained that the hydrophones work together to listen to the undersea environment from various directions, and the sound signals are analyzed, filtered, and detected by a signal processor. The combination of Target Motion Analysis with the towed array system is intended to manage noise and improve performance.

The joint research project will involve data sharing, live trials, and testing of algorithm performance, allowing both countries to leverage their combined technological capabilities. Suneel Randhawa, Chief of the Information Sciences Division at DSTG, noted that with the evolving nature of the underwater battlespace and the increase in autonomous underwater systems, such innovations are crucial. The collaboration may also integrate artificial intelligence (AI) and machine learning (ML) for advanced signal processing, aligning with global trends in sonar technology development.

India's recent success in trialing a moored autonomous underwater sonar system in the Bay of Bengal from May 17–19, 2025, highlights NPOL's growing expertise in underwater acoustics, which will enhance the joint project's outcomes. Officials anticipate that the research could influence the development of future undersea surveillance systems and bolster the strategic deterrence abilities of both nations. The collaboration also highlights the strengthening defense partnership between India and Australia, especially within the Indo-Pacific region. By combining resources and technical know-how, the two countries aim to expedite innovation and deliver effective undersea detection technologies tailored to modern maritime security challenges.