Augmented Commercial Radio for Navigation (ACORN)

The Global Positioning System (GPS) and other global navigation satellite systems (GNSS) are the critical providers of position, navigation, and time (PNT) information to an almost uncountable number of users and applications. Widespread dependence on GPS has led to awareness that GPS data availability is a single point of failure for many systems and applications. In addition, GPS signals are very weak, leading to threats of jamming (interference) and spoofing (transmission of false signals) from both hostile and accidental sources. These risks to GPS have significant economic and public health and safety impacts. Users need assured PNT, that systems and operations can be assured of both the availability and integrity of PNT data. Augmented Commercial Radio for Navigation (ACORN) is a general purpose, nationwide PNT capability, that operates by augmenting existing commercial broadcast transmissions to provide high-accuracy, high-availability, and high-integrity PNT data. The Phase I study indicates that ACORN should provide more accurate data than GPS L1 C/A code and support an unlimited number of simultaneous users operating indoors, outdoors, and airborne. The Phase II effort will implement and test prototype devices, validate performance expectations via test, and prepare for commercialization.