Navigational systems of autonomous vehicles, integrate positioning signals from a variety of sources, each of which may have certain limitations. Inertial navigation systems (INS) are prone to accumulated uncertainty errors when operating alone but are often paired with other systems. Added sensors such as cameras, lasers, and sonar may be too large or expensive in some cases. Global positioning system (GPS) signals can be lost in dense urban environments or altered by a malicious attack, so other sensor-less and GPS-independent signals are needed to ensure and improve autonomous navigation.
While cellular phone networks are not designed for navigation, they are abundant in urban environments which are known to challenge GPS signals. University of California, Riverside researchers integrated signals-of-opportunity from mobile phone networks to provide autonomous vehicles with precise navigational information.