Safety considerations for UAS ground-based detect and avoid

We describe a generic mission concept of low altitude beyond visual line of sight unmanned aircraft system (UAS) operations, in which a ground-based detect and avoid (GBDAA) capability is to be used. First, we discuss some of the variations in the underlying missions and their bearing on providing assurance of safety in operations. Then, drawing upon the experience gained in developing safety assurance cases for many such missions, we summarize the different GBDAA safety considerations pertinent for mission safety. Additionally, we present some of the patterns of safety reasoning that we have used in the safety cases, which take the form of abstract argument structures. The overall goal of this work is to develop an infrastructure that can guide safety assured design of future UAS missions that use GBDAA, while providing rapid feedback on overall mission safety.