Time and Frequency

Complete System for Shipborne Application

Modern naval platforms rely on a common, precise time reference for navigation, communications, combat systems, and weapon control. Many of these systems use STANAG and HaveQuick (HQ) time codes as their primary timing reference. The marine environment presents unique challenges including limited GNSS availability, electromagnetic interference from ship systems, shock and vibration, and the need for redundant timing paths across multiple compartments.

This application note describes a typical marine time-synchronization architecture based on our time and frequency products, providing a robust, redundant, and scalable distribution of timing signals across the ship.

A marine timing system must satisfy the following requirements:

• Provide GNSS-disciplined master time from multi-constellation receivers

• Generate 1PPS, IRIG-B, and 10MHz references for ship subsystems

• Distribute timing signals to multiple consumers: CMS, radar, EW, SATCOM, weapon control, INS, etc.

• Offer redundancy and fault-tolerant distribution

• Support remote monitoring from the ship's IP network (SNMP, web)

• Maintain timing continuity during GNSS denial via holdover oscillators

• Withstand harsh marine environmental conditions (temperature, humidity, vibration, EMI)

The architecture consists of a central timing generation hub and distributed timing access nodes connected via fiber optic links.

At the central timing hub, the GS3114 PNT Server receives GNSS signals from multi-constellation antennas and generates the master timing references: 1PPS, 10MHz, IRIG-B(DC), and NTP. It also provides positioning data for the ship's navigation systems. A secondary GS3114 operates in hot standby, ready to assume master timing duties if the primary unit fails.

The GS5250 seamless switcher manages transitions between GNSS-locked mode and inertial navigation timing during GNSS denial. The GS5227 provides redundant 1PPS/10MHz distribution to local systems in the combat information center.

For distribution to remote compartments, the GS5710 fiber optic transmission equipment converts electrical timing signals to optical, transmitting them over shipboard fiber infrastructure. At each destination compartment, a GS5710 receiver recovers the timing signals for local distribution via GS6605A 1PPS distributors and GS6601A 10MHz amplifiers.

• Prefer RS422 outputs for long cable runs through electromagnetically noisy compartments

• Use shielded twisted pairs and proper grounding throughout the ship

• For high-critical missions, deploy two GS3114 units in A/B configuration with automatic failover

• Integrate all timing equipment into the ship's NMS using SNMP and SYSLOG for alarm reporting

• Use armored fiber optic cables for inter-compartment links to meet shock and vibration requirements

• Verify EMC compliance of all timing equipment against relevant naval standards

By combining the GS3114 PNT Server as the GNSS-disciplined master time generator, GS5250 for robust source switching, GS5227 for redundant 1PPS/10MHz distribution, and GS5710 for fiber optic transmission between compartments, a ship obtains a coherent, robust, and scalable marine time distribution system. This architecture is suitable for surface combatants, patrol vessels, support ships, and coastal stations requiring reliable time synchronization for mission and weapon systems.