Citation

Lee S, Wu MG, Cone AC. J. Air Transp. (Rest.) 2021; 29(4): 171-183.

Copyright

(Copyright © 2021, American Institute of Aeronautics and Astronautics)

DOI

10.2514/1.D0246

PMID

unavailable

Abstract

A detect-and-avoid system serves as a critical component for unmanned aircraft systems to remain "well clear" from and avoid collisions with other aircraft to operate in the National Airspace System. An appropriate definition of detect-and-avoid well clear is required for encounters between an unmanned aircraft and a noncooperative aircraft, which is an aircraft operating without an active transponder. Four candidate well clear definitions are evaluated for different speed categories of unmanned aircraft based on alerting performance metrics using a fast-time simulation framework with a large number of representative encounters. Impact of limited surveillance volumes, in terms of detection range, and horizontal and vertical fields of regard, on the alerting performance of a detect-and-avoid system is investigated.

RESULTS show that one of the four candidate definitions, a cylindrical volume of well clear definition without a temporal parameter, has the potential of reducing the required surveillance detection range the most. Furthermore, given the same surveillance volume, this cylindrical well clear definition provides longer average alert times before a loss of well clear volume. This study suggests that the cylindrical well clear volume can be used as a single well clear definition for noncooperative intruders.

Language: en