unmanned aircraft, sense and avoid, detect and avoid


For unmanned aircraft systems to gain full access to the National Airspace System, they must have the capability to detect and avoid other aircraft. To safely avoid an- other aircraft, an unmanned aircraft must detect the intruder aircraft with ample time and distance to allow the ownship to track the intruder, perform risk assessment, plan an avoidance path, and execute the maneuver. This paper describes two analytical methods for finding the minimum detection range to ensure that these detection and avoidance steps can be carried out. The first method, time-based geometric velocity vectors, includes the bank-angle dynamics of the ownship; whereas the second, geo- metric velocity vectors, assumes an instantaneous bank-angle maneuver. The solution using the first method must be found numerically, whereas the second has a closed- form analytical solution. These methods are compared to two existing methods. The results show the time-based geometric velocity vectors approach is precise, the geo- metric velocity vectors approach is a good approximation under many conditions, and the two existing approaches are good approximations at large ownship speeds relative to the intruder speed, fast ownship bank-angle transients, and small ownship bank angles.

Original Publication Citation

Wikle, Jared K., et al. "Minimum Required Detection Range for Detect and Avoid of Unmanned Aircraft Systems." Journal of Aerospace Information Systems (2017).

Document Type

Peer-Reviewed Article

Publication Date


Permanent URL






Ira A. Fulton College of Engineering and Technology


Mechanical Engineering

University Standing at Time of Publication

Graduate Student