Data abnormalities and drop outs in North Dakota air traffic control radar

To assess the radar systems in North Dakota (ND) and its surrounding areas and their ability to provide Detect and Avoid (DAA) capabilities for both manned and unmanned aircraft, a study was completed to understand their performance. This assessment will provide an evaluation of typical radar performance throughout the year, including rates of anomalous behavior. With the likely increase in airspace congestion due to the integration of Unmanned Aircraft Systems (UAS) over the coming years, the need for a reliable and robust radar system is critical. This investigation focused on both primary and secondary radar at the Air Route Surveillance Radar (ARSR) in Finley, ND and the Airport Surveillance Radar (ASR) in Fargo, ND. The work has shown that both radars produce data that includes drop outs and data anomalies. The data anomalies included: altitude discrepancies, repeated data, prolonged altitude failure, and multiple aircraft with the same ID number. Using a computer algorithm that was developed to process four weeks of data, the results showed that 34% of aircraft experienced drop outs at Fargo and 69% of aircraft at Finley. Also, between 1-26% of aircraft experienced data anomalies, depending on the type of anomaly and location. It was found that these anomalies typically occurred on the outside of the effective radar radius and near airports. An investigation was also done to understand if the behaviors were induced by the radar or the transponder on the aircraft. These findings will prove invaluable to the UAS industry and for the development of autonomous Air Traffic Control (ATC) systems.