TABLE OF CONTENTS In describing the evolution of satellite navigation (see Section 1.2 in Chapter 1), a contradictory and fascinating portrait of the GPS can be derived.
GPS, the system used for positioning, tracking, and mapping in most cases is mentioned as synonymous with navigation; GPS is the means that has translated the theoretical concept of navigation (see Chapter 2) into an actual system, a quite friendly receiver, a commonly accepted and increasingly needed service.
It is designed to be a low-cost solution for civilian users; however, it has been conceived and continues to be maintained by U.S. military institutions, albeit with a contribution from the U.S. Department of Transportation.
It is global in scope, available on a 24/7/365 basis (i.e., always), but it can be denied to civilian users due to defense-based security reasons.
It is accurate, but its performance could be intentionally degraded (as was the case for more than 10 years until 2000) to ensure U.S. national security by denying accurate real-time autonomous navigation to unauthorized users.
GPS has been a continuous source of technology deployment for onboard and on-ground hardware and software. It has brought into action a competitive scenario for conceiving and deploying future systems and innovative services that render navigation a key aspect of people s future welfare.
Extensive literature has been written on GPS [1 9], including very detailed books and research papers [10 12]. Hence, these will not be reproduced here. However, the GPS architecture and organization, signal structure, and performance issues are covered here. An...
