Abstract:Unmanned aerial systems capable of beyond visual line of sight operation can be organized into a top-down hierarchy of layers including flight supervision, command and control, simulation of systems, operating systems, and physical hardware. Flight supervision includes unmanned air traffic management, flight planning, authorization, and remote identification. Command and control ensure drones can be piloted safely. Simulation of systems concerns how drones may react to different environments and how changing conditions and information provide input to a piloting system. Electronic hardware controlling drone operation is typically accessed using an operating system. Each layer in the hierarchy has an ecosystem of open-source solutions. In this brief survey we describe representative open-source examples for each level of the hierarchy.