Aerial RIS-Assisted Integrated Sensing and Semantic Communication for Low-Altitude Maritime Intelligent Networks

Semantic communication conserves spectrum, while UAV-mounted RIS enhances communication flexibility—key for the low-altitude economy. Their integration improves wireless performance but remains vulnerable to eavesdropping. Maritime communication adds challenges like dynamic channels and difficulty in locating sea users and eavesdroppers. To address this, we propose a secure UAV-RIS-assisted communication scheme integrating semantic communication and integrated sensing and communications (ISAC). It maximizes secrecy semantic rate, reduces energy consumption. By jointly optimizing UAV-RIS trajectories, RIS phase shifts, and spectrum allocation, to strengthens security. We propose an approach, combining semantic communication, weight decay deep double deterministic policy gradient, and dueling deep Q-network (S-WDDU), effectively supports UAV-RIS-assisted communication in maritime environments. Simulations show it outperforms existing methods in both security and energy efficiency, enhancing performance of low-altitude intelligent network in the low-altitude maritime economy.