The Communication, Navigation and Surveillance (CNS) systems provide air traffic controllers with the information necessary to ensure the specified separation between aircraft and efficient management of airspace, as well as assistance to flight crew for safe navigation. However, the radar systems that support air traffic management (ATM), and in particular air traffic control (ATC), are at their operational limit. This is particularly acute in the provision of the ATC services in low altitude, remote and oceanic areas. Limitations in the current surveillance systems include unavailability of services in oceanic and remote areas, limited services during extreme weather conditions, and outdated equipment with limited availability of spare parts to support system operation. These limitations have resulted in fatal accidents. This book addresses the limitations of radar to support ATC in various operational environments, identified and verified by analysing five years of safety data from Avinor, the Air Navigation Service Provider (ANSP) in Norway. It derives a set of taxonomy and from this develops a causal model for incident/accident due to limitations in the surveillance system. The taxonomy provides a new method for ANSPs to categorize incidents while the causal model is useful for incident/accident investigations. The book also provides theoretical justifications for the use of Automatic Dependent Surveillance Broadcast (ADS-B) to overcome the limitations of radar systems and identify areas of improvements to enable seamless ATC services. Written in a style that makes it accessible to non-specialists, Aircraft Surveillance Systems will be of interest to many in the field of aviation, particularly ATM, safety and accident/incident investigation. It will also offer a useful reference on this vital topic for air traffic management courses.