Performance Analysis of Low-Cost AIS Receiver Using RTL-SDR and Raspberry Pi: A Study on Minimum Field Strength and Optimal Gain

The Automatic Identification System (AIS) plays a vital role in maritime safety, yet conventional receivers remain cost-prohibitive for widespread deployment. This study develops a low-cost AIS receiver solution utilizing RTL-SDR hardware and Raspberry Pi, with emphasis on signal processing efficiency and minimum field strength compliance. The proposed system captures VHF signals at 162 MHz, demodulates GMSK-modulated data streams, decodes HDLC protocol frames, and stores processed data in a MySQL database for real-time vessel tracking. Field testing confirms operational reliability within a 15 -kilometer range under typical noise conditions, maintaining packet error rates below 5 percent. The modular architecture facilitates integration with IoT platforms for enhanced maritime monitoring capabilities. Performance evaluations demonstrate stable reception at 80 dB gain with minimum field strength of -110 dBm, achieving 95 percent decoding accuracy for dynamic vessel information. With total hardware costs under 100 USD and open-source software components, this solution presents a practical alternative to commercial AIS receiver systems.