UK Critical National Infrastructure (CNI) is at significant risk from the loss of access to GNSS for PNT. LF systems such as eLoran can provide a highly robust complement to GNSS. An eLoran transmitter can serve applications hundreds of miles away but the accuracy of the time transfer depends on the radio propagation (at ground level) between the transmitter and the receiver. At levels of precision required for many CNI applications the accuracy is significantly dependent upon the signal delay that the ground introduces, which varies according to several factors such as weather conditions. The UTD project aims to address that knowledge gap, providing a key step towards national exploitation of eLoran based precise timing transfer.

The project will aim to address the longer-term objectives of strategic defence and national CNI which require resilient UTC traceable time as detailed in the UK Government Blackett Review. The vulnerability of GNSS signals reception to natural and man-made interference is well known and UTD will research the degree of precision to which eLoran can provide precise timing throughout the UK and beyond over indefinite periods of GNSS outages traceable to UTC.

Chronos Technology Limited is a global authority on resilient synchronisation and timing solutions, and, GNSS interference and mitigation technologies providing expertise in two key market areas, time synchronisation in communication networks, and, GNSS derived applications that utilise GNSS signals. With over 35 years’ experience of designing, implementing and maintaining synchronisation infrastructure in Tier 1 Networks, Chronos provides solutions across all industry sectors, with especially strong expertise in the broadcast, defence and security, energy, enterprise IT, finance, telecom and transport sectors. Chronos is the founder and steering group member of the International Timing and Synchronisation Forum, and is a member of the following expert associations, ITU-T SG15/Q13, Royal Institute of Navigation, Institute of Navigation, Power Networks Distribution Centre, Institute of Engineering & Technology, and is a steering group member of the North American Workshop in Synchronisation and Timing Systems.
Chronos Technology Ltd is currently working with ESA on various NAVISP funded projects as a sub-
contractor to Telespazio and Powerline Technologies Ltd.