Threats from intentional jamming and spoofing of U.S. Global Positioning System (GPS) signals demonstrate the need for a powerful, secure and resilient time and frequency system to ensure continuing operability and performance. The SyncServer S650 M-Code is the first time and frequency instrument with an embedded GPS M-code receiver. It has received security approval from the U.S. Air Force GPS Directorate to provide a secure, accurate, and flexible timing platform for synchronizing mission-critical electronic systems, instrumentation, communication systems, radars and networks.