Japan is testing an unknown upgrade for the UH-2 multi-role helicopter of its Ground Self-Defense Force. Images released by an aviation photographer show the helicopter equipped with two new dome-shaped antennas on the cabin roof — equipment not previously seen in flight and has drawn attention from military analysts. Some experts believe the system is designed for signals intelligence (SIGINT) missions, while others suggest it could be part of the HeliSAT system for live aerial reconnaissance image transmission and disaster relief support. The UH-2 helicopter entered service in 2022 as a replacement for the UH-1J, and Japan's Ministry of Defense has not commented on the nature of this new upgrade.