Real-Time Vessel Monitoring Using Low Cost RTL-SDR with Web-Based AIS Visualization

Ship traffic monitoring plays a vital role in observation, research, maritime security, and navigation safety. The Automatic Identification System (AIS) is an international standard for vessel tracking, creating a demand for efficient and affordable AIS receiver solutions. This paper presents a low-cost AIS receiver system built with RTL-SDR and Raspberry Pi devices. The system uses a C-based decoder to perform GMSK demodulation, NRZI decoding, and CRC16 error checking, ensuring high data accuracy. Decoded information is stored in a MariaDB database and visualized in real time through a web-based interactive map. The platform displays vessel positions, movements, and detailed information, with additional features such as ship filtering, playback controls, weather overlays, and distance measurement tools. Field tests demonstrate that the system achieves over 99% decoding accuracy with minimal latency, making it suitable for localized coastal monitoring. This approach offers a scalable and cost-effective alternative to conventional AIS receivers, supporting both research and operational applications in diverse maritime environments.