GPS spoofing, GNSS interference, and other positioning anomalies mean the on-screen position can’t always be trusted. TZ Professional v5.4 strengthens Dead Reckoning—an independent, motion-based backup—to help mariners keep navigating and spot suspicious GPS behavior sooner.
What’s improved in v5.4
Easier to access and manage: Dead Reckoning settings are now grouped in a dedicated Options section, making core controls quicker to find.
- Enabling Dead Reckoning
- Displaying the Ghost Ship
- Monitoring GPS deviation
Ghost Ship (spoofing detection)
- Ghost Ship runs a Dead Reckoning track alongside GNSS, using heading and Speed Through Water (instead of GPS) as an independent reference.
- Use it to compare the GPS position to a motion-based estimate.
- If the separation grows beyond your threshold, an alarm can warn that the displayed GNSS position may be unreliable.
Radar-assisted position verification
- Works with Furuno radar so you can cross-check position using radar overlay and known references (e.g., coastline, buoys).
- In Dead Reckoning mode, you can manually shift the vessel position to match the radar picture; the corrected point becomes the new reference for ongoing estimates.
More accurate position estimation
Dead Reckoning can now incorporate transverse water speed from sensors such as the Furuno DS 60 or Airmar DX900+ in addition to Speed Through Water, improving estimates when the vessel is pushed sideways by wind, sea state, or current.
More flexibility when data is incomplete
In degraded conditions v5.4 extends Dead Reckoning so it can keep running with whatever data is available.
- Automatic mode when heading and speed are available
- Manual entry when either heading or speed is missing
- Expanded manual mode for very limited data
- Estimated position input through LOP tool
This ensures that users can maintain navigation continuity even in degraded conditions, instead of losing the benefit of Dead Reckoning when it is needed most.
Why this matters
With these updates, Dead Reckoning helps users:
- Maintain an estimated position without relying on GPS
- Detect GPS spoofing and suspicious GNSS behavior
- Compare GNSS data with an independent motion-based reference
- Continue navigating when onboard data is incomplete
- Verify and correct position using radar
Conclusion
GPS spoofing and GNSS disruption while rare are becoming increasingly more common. Safe operations require tools that verify and cross-check position—not just display it.
Dead Reckoning in TZ Professional v5.4 is built to maintain navigation continuity and help confirm whether GNSS data is trustworthy.
