DEAD RECKONING EXPLAINED – ACCURATE TRACKING WITHOUT GPS: KEY TAKEAWAYS

Cities are changing rapidly. By 2050, an estimated 68% of the world’s population will live in urban areas. What does this mean for telematics? With surface space limited, cities are building downwards with tunnels, underground parking and dense infrastructure. That is exactly where the GPS signal is often lost. As urban infrastructure evolves, Teltonika adapts – and this is where the dead reckoning feature steps in to address these near-future challenges.

WHAT IS DEAD RECKONING?

Dead reckoning is a navigation technique used to estimate a vehicle’s current position and direction of movement based on its previous position and known speed. It uses additional sensor data to correct the position received from the GPS receiver. These sensors detect speed, turns and orientation, so even without a satellite signal the route can continue to be calculated. In simple terms, it is a technology that keeps tracking active when the GPS signal is lost.

WHAT IS THE VALUE OF DEAD FOR TELEMATICS?

When thinking about the future of telematics, it is essential to return to its foundation - location tracking. Under open skies, modern GPS technology delivers highly accurate and reliable data. However, the industry now faces a growing challenge – blind spots. Tunnels, underground parking lots, and narrow urban streets surrounded by tall buildings can block or reflect satellite signals, leading to GPS signal loss. These blind spots lead to inefficiencies, wasted time, financial losses, and reduced trust from businesses that depend on accurate data.

For many companies, virtual odometer readings play a critical role in operations. This is where dead reckoning becomes a game-changer – it ensures precise distance tracking even when GPS is unavailable. The result is reliable fuel reports, validated trip data, and greater transparency, all of which strengthen driver and customer trust.

Without dead reckoning, traditional GPS simply connects the dots between two points, skipping entire segments of a trip – most commonly in tunnels or underground areas. The lost data leads to inaccurate mileage and reporting, which can directly affect business operations.

Beyond accuracy, dead reckoning enhances vehicle security. Even when GPS signals are jammed or blocked, the system continues to record movement, allowing for effective stolen vehicle recovery and preventing additional financial losses.

Finally, dead reckoning opens new possibilities for car-sharing and fleet management services in multi-level or underground parking environments. As cities grow and street parking becomes scarce, these locations represent the future of car-sharing. Until now, vehicles parked underground were virtually invisible. With dead reckoning, telematics service providers can now offer seamless connectivity and accessibility – anywhere, anytime.

Q&A

At the end of each of our webinars, we host a live Q&A session. Below, you will find some of the participants’ questions along with answers from our experts. How does dead reckoning work?

When the GPS signal is lost, dead reckoning calculates the vehicle's position using:​

• Accelerometer, which detects how fast or slow the vehicle speeds up or slows down.​

• Gyroscope, which tracks orientation and movement. It detects turns and tilts.

Which devices will feature dead reckoning?

This feature is developed exclusively on the FT platform. While all FT platform devices include integrated accelerometer and gyroscope sensors, not all of them will support dead reckoning functionality. The first devices to feature dead reckoning will be the FTx927 and FTx887, available in both connectivity options – 4G LTE Cat 1 and 4G LTE Cat M1.

• FTx927 is based on our bestselling FMx920 device, commonly used for anti-theft and stolen vehicle recovery solutions, as well as for immobiliser scenario, since it offers all essential interfaces for such use cases.

• FTx887, on the other hand, is a battery-mounted device designed for those who need quick and easy installation along with a robust IP69K-rated casing. This device is perfect for insurance or delivery companies, especially now as it will be easier to monitor driver behaviour in tunnels, parking lots or detect events, where the GPS signal is lost.
  

Both devices will be available in multiple versions suitable for use across the globe – Europe, Japan, North America, and beyond. In later stages, additional variants will be introduced for different markets and regions.

Will FTx927 and FTx887 devices be the only ones with dead reckoning?

Definitely not. These two devices will be the first, but more devices with dead reckoning are on the way. The easiest way to determine whether a device supports dead reckoning is to look for the number 7 or higher in the device name. By understanding Teltonika’s tracking device naming logic, you can easily identify a device’s core features, such as dead reckoning.

What is a virtual odometer? How are dead reckoning and virtual odometer data related?

The virtual odometer represents the total distance calculated by the GPS tracker. It is virtual because it does not rely on the vehicle’s provided data (seen on a dashboard); instead, it continuously calculates distance based on movement data recorded by the GPS tracker.

Dead reckoning enhances the accuracy of the virtual odometer by filling in missing distance data when GPS is unavailable (for example, in tunnels, parking garages, or dense urban areas). This ensures the virtual odometer continues to update seamlessly, delivering accurate and reliable tracking data even without a GPS.

Where can dead reckoning be applied?

In short, everywhere. Whether a vehicle is entering a tunnel, navigating narrow city streets, or parked in an underground garage, dead reckoning is the technology you need to maintain continuous tracking. During our webinar, we asked participants where their businesses face the biggest challenges and where they see potential for using dead reckoning. Half of the respondents highlighted that their main use cases are tracking in tunnels and underground areas, confirming that maintaining accurate tracking data in such environments remains a common challenge.

Will dead reckoning show the vehicle’s route inside a tunnel (including curved tunnels)?

Yes, dead reckoning provides continuous tracking data inside tunnels, including curved sections. It calculates and displays both the route and the vehicle’s speed while the GPS signal is unavailable.

Does dead reckoning require any specific type of installation?

To achieve maximum results, it is better to prepare device correctly. The detailed information on proper preparation is available on our wiki page.

Firstly, the device must be mounted firmly in the vehicle, with good visibility of the sky. You can review good mounting examples on our wiki. Secondly,  since the dead reckoning feature is available only with FT platform devices, you should know that it is configurable via the dead reckoning section in the GNSS settings group under system view in Telematics Configuration Tool (TCT).  Finally, once device mounting adheres to the guidelines, alignment can be performed. The device must finish a specific alignment process to determine its mounting orientation. During this process, there are specific conditions that must be met:

• The device must be stationary with clear sky visibility for at least 3 minutes.

• The speed of the vehicle must not be below 10 km/h or exceed 50 km/h.

• Avoid driving in underground tunnels or areas with a poor GPS signal, otherwise, alignment needs to be restarted from the second step.