Understanding Vertical Collision Risk and Navigation Performance for Unmanned Aircraft

This paper considers the problem of quantifying the vertical overlap probability or vertical collision risk associated with unmanned aircraft operations around aerodromes. The risk models combine real surveillance data and expectations on altitude keeping errors of both manned and unmanned aircraft with well-established collision modelling approaches used in manned aircraft separation standards development. To demonstrate the utility of the proposed vertical collision risk model, a series of investigations are conducted to quantify the vertical collision risk associated with approaching and departing aircraft and the relative impact of unmanned altitude keeping performance. Results demonstrate some shortfalls of current exclusion zones near aerodromes and the need to better understand unmanned navigational errors when considering future unmanned traffic management.