Advances in the Use of NAS Infrastructure and GBDAA for UAS Operations

Abstract

A Ground Based Detect and Avoid (GBDAA) system, derived from the Terminal Automation Modernization Replacement (TAMR) system, the terminal air traffic control (ATC) automation system currently in use in US National Airspace (NAS) continues to evolve to provide enhanced detect and avoid decision making for unmanned aircraft (UA) operating in the NAS. GBDAA capabilities have been developed as a partnership between the USAF, State of Ohio, DOT Volpe Center, MITRE and Raytheon. The system displays airborne tracks provided by a collection of sensors for situational awareness and proximity alerts to crew and mission planners. Large and small unmanned aircraft systems (sUAS) operations are supported using both fixed and mobile facilities. The GBDAA system allows the pilot to make decisions about flight maneuvers without using ground observers or chase planes during day and night operations. Recent enhancements include the use of a separate GBDAA Operator (GO) display, synchronized with the UA's Pilot in Command's (PIC) display to allow for the safe passage of the UA throughout its operational airspace. The GO supports the PIC with alert prioritization and maneuver recommendations, allowing the PIC to focus on piloting tasks and reduce the time needed for avoidance maneuvers. Several types of UAS operations are described that include: • Table top sUAS operations at a small airfield • Medium sized unmanned aircraft (UA) Ground Control Systems (GCS) such as those used for Predators/Reapers and mobile cart technology. • Larger UAS operations such as those used for the Global Hawk with a separate mission operations center • Airspace utilization, such as transit corridor operations, transition from terminal operations to Class A airspace, and free flight considerations The availability of surveillance coverage and the size of the UAS operational airspace that can be supported can be determined based on available surveillance assets and airspace environment at each location. In many cases, existing surveillance assets are used to provide the information needed on the airspace being monitored. New radar equipment and modifications to existing surveillance assets can be used to augment existing ATC sensors and close surveillance coverage gaps. GBDAA decision making is provided by new software and the use of multisensor fusion tracking software that supports the display of track information for both cooperative and noncooperative targets. These are displayed to both the GO and PIC using a common situation display showing the operational airspace. Several ever increasingly urgent levels of proximity alerts are displayed to both flight crew members as they perform their respective tasks. This paper describes important aspects of the development of a mobile facility as the team integrated access to FAA surveillance radar assets, radio and telecommunications gear to create a complete set of GBDAA services that can be installed at different sites. The necessary airport field work, integration of surveillance, radio and phone connections and the installation of a fully functional GBDAA system into a 36-foot modified recreational vehicle is described. This “GBDAA Bus” provides a working environment to support operations for sUAS stakeholders carrying out different missions for both AFRL and the State of Ohio's UAS Center. Where no access is available to certified FAA/DoD airport surveillance and long-range radar sensors, several different types of towable sensors can be used, some even offering elevation approximation for non-cooperative targets.