The Global Positioning System (GPS) has revolutionized military operations by providing global access to high-quality position, navigation, and time (PNT) data. Along with the rise in GPS usage has been a parallel increase in threats to GPS data availability. GPS signals are easily jammed due to their low signal power and fixed frequency of operation. Spoofing attacks threaten military systems being fooled by fake transmissions that mimic GPS signals. News reports suggest that some hostile nations have contemplated anti-satellite weapons to be used against the GPS constellation. Cyber-attacks are always a risk against the ground control segment and other aspects of the system. There is a pressing need for PNT data availability for military systems provided by means other than GPS. In addition, with increasing precision of some military systems, there is also a critical need for position and time data that is more accurate than GPS can provide. Accurate Ranging and Time Transfer (ARTT) is conceived to provide ultra-high accuracy ranging, time, and frequency transfer that is flexible in implementation and thereby integrable across a diverse range of military systems, proving a tool for assured PNT for military operations.
