European Space Agency (ESA) NAVISP-funded project LOCFIT (‘Localization for IoT and tracking’), led by Thales Alenia Space France with partners Qascom, Kinéis and Traxens, has explored infrastructure-based position-bounding solutions that exploit satellite uplink measurements from connected devices.
GNSS position bounding defines a confidence region around a reported position, indicating the maximum likely error and providing integrity information for reliable and safety-critical navigation applications. For applications such as container tracking, maritime monitoring or land transportation of critical assets, the key question it answers is not only ‘where am I?’ but ‘how wrong could my position be?’
The LOCFIT solution compares the GNSS position reported by an asset tracker with independent measurements derived from satellite communication uplinks. By checking the consistency between these measurements, the system can compute a bound within which the true position is guaranteed, or detect when something is wrong. This approach is particularly well suited to low-energy devices designed to operate for years without maintenance.
The project team chose container tracking as the reference use case to define service-level requirements, reflecting real operational constraints such as limited satellite visibility in ports, depots or on ships, low data rates and strict energy budgets. The project looked at several system architectures and uplink measurement techniques, including time-difference-of-arrival and round-trip-time methods, and assessed their robustness against realistic attack scenarios.
Final results
The LOCFIT project was presented by Etienne Rouanet-Labe of Thales Alenia Space France and Federica Rozzi of Qascom at a recent ESA-hosted event. Using a dedicated software testbed with representative IoT and satellite data, the team demonstrated that position verification at the 500-metre level is achievable with high availability and no false alarms under nominal conditions. In addition, the system proved effective at detecting GNSS spoofing and record-and-replay attacks, even when the reported GNSS position appears plausible.
As GNSS becomes central to logistics, transport and asset tracking, its vulnerabilities have become more apparent. Jamming, spoofing and signal masking can undermine positioning and localization, especially for low-cost, low-power IoT devices with limited sensing and connectivity.
Rouanet-Labe called the results of the LOCFIT exercise encouraging, showing satellite communication infrastructure can play a direct role in securing positioning services, providing independent integrity information that does not rely solely on GNSS signals. For SBAS end users and future hybrid navigation services, the work suggests a path toward more resilient positioning, where confidence bounds and integrity alerts remain available even in challenging or hostile environments.
