Experimental ADS-B based surveillance Juan A. Besada, Gonzalo de Miguel, Ana Bernardos, José Ramón Casar GPDS-CEDITEC Universidad Politécnica de Madrid Madrid, Spain besada@grpss.ssr.upm.es Abstrae*— This paper describes an ADS-B implementation in air- to-air and ground based experimental surveillance within a prototype ATM system. The relations between airborne and ground systems related to surveillance are detailed, and the prototype surveillance systems and their algorithms described. Their performance is analysed, based both on simulated and real data. ADS-B; TÍS-B; Air Surveillance; Ground Surveillance I. ÍNTRODUCTION The Automatic Dependent Surveillance-Broadcast (ADS- B) [3][4][5] is a key enabler for all future Air Trafile Management (ATM) proposals, as it allows for both ground and air surveillance. As the surveillance function is a prerequisite for separación assurance (airborne and in ground), and ground flight intent conformity checking, this is a critical technology for civil i an air traffíc control. It is foreseen that, in coordinaron with Wide Área Multilateration Systems and Mode S radar it will progressively phase out current Secondary Surveillance Sensors. As not every aircraft will be equipped with ADS-B enabling avionics, a complementary service to provide ground surveillance results (from other sensors) will have to be equipped to aircraft. This is the Trafile Information System-Broadcast (TIS-B) [6]. The research described in this paper has been performed within ATLÁNTICA, an Spanish project aiming to implement a completely automatic prototype of an future ATM system with Unmanned Aircraft Systems (UASs). The proposed air and ground surveillance systems have been implemented for INDRA S.A. within this project and is integrated in the ATLANTIDA avionics and traffíc management prototypes. One novelty in ATLANTIDA is the integration of such a system in a complete Trajectory Based Operation (TBO) framework for ATM with an air-inclusive SWIM (System Wide Information Management) middieware connecting all ATM systems, This SWIM concept, also present in SESAR [I] and NEXTGEN [2], assumes all data interchange and information retrieval demands are covered with a unique communícation infrastructure. ADS-B was implemented over a SWIM network comprísing both ground and airborne equipment. In ATLANTIDA the following objectives of an ADS- B/TIS-B based surveillance solution were investigated: • Design of a SWIM oriented protocol for ADS-B. We defined new ADS-B messages and protocols for experimentation, as it is mainly a software-based solution using standard hardware and middieware, instead of current approaches based on the use of certified data-buses and hardware, • Design and implementation of a complete ADS-B based ground surveillance, with all the typical surveillance functions (measurement association, track initiation and deletion, measurement filtering, integrity tests to increase reliability, ...) and additional procedures for ADS-B induced computational load management. • Design and implementation of a complete ADS-B based air surveillance, with a functionality similar to ground surveillance, but with additionally stringent computational requirements, and with the particularity of being implemented in a mobile platform. • Inclusión of new data formats providing on-board meteorological measurements to a ground facility, to enable high quality tuning of meteorological models. • Inclusión of new data formats to enable air-to-air communication of aircraft intents, to support potential extensions of ATLANTIDA concept to ASAS (Airborne Separation Assurance Systems). This paper starts (section II) with a brief introduction to currently available ADS-B and TIS-B technologies, and some related surveillance technologies. Then (section III) it will describe the relation of air and ground surveillance systems with other avionic and ATM systems. Based on previous requirements, it will define the new data formats and protocols to be used in ATLANTIDA and subsequent work (section IV). Sections V and VI will describe intemal air-to-air and ground surveillance systems structure and algorithms, Finally, the paper will include a simulation based performance evaluation of the system in section VII; and it will draw some conclusions and describe future research lines in section VIII. II. CURRENT ADS-B AND TIS-B IMPLEMENTATIONS There are several competing technologies for ADS-B implementation. Next we are summarizing some of the most important points of those implementations, especially with regards to the information they may provide, and to the protocols related with this communication.