Cydome GPS/GNSS Spoofing Monitoring is a maritime cybersecurity solution that detects GPS and GNSS spoofing and jamming incidents in real time, without requiring dedicated hardware. The solution continuously monitors navigational data directly from a ship's onboard sensors and cross-validates readings against multiple independent sources to identify anomalies and inconsistencies indicative of spoofing or jamming activity. When a spoofing or jamming event is detected, the system immediately alerts both the ship crew and the onshore team, enabling them to avoid sole reliance on compromised GPS readings and take corrective action before navigational errors escalate. The solution covers major Global Navigation Satellite Systems including GPS, Galileo, GLONASS, and BeiDou, and addresses two primary disruption types: - GNSS Jamming: Transmission of signals in GNSS frequencies designed to disrupt data flow by introducing noise and blocking reception. - GNSS Spoofing: Crafted transmissions intended to produce manipulated position or timing readings. The system is designed for maritime environments where GPS/GNSS spoofing incidents are frequent, with the stated context of over 1,000 daily incidents globally. Its primary value is enabling faster response and minimizing safety and operational risks associated with navigational data manipulation.