The history of GPS is heavily weighted toward the remarkable story of how GPS was conceived and constructed. Frank van Diggelen is one of the architects of Assisted GPS, which is largely unknown to most GPS users. From his Oral History we learn that GPS signals are too weak to be acquired by an unaided smart phone. The fact that GPS is even available on hand-held devices came about because of a 911 deficiency. The location of early cell-phone emergency calls was unknown.
Dr. van Diggelen also points out that while the first bulky military GPS receivers achieved sub-meter accuracy, inexpensive hand-held A-GPS devices are now capable of achieving the same accuracy. New applications are evolving at a Moore’s law pace.