Relative position indicator concept for managing mixed RNAV and vectored arrival traffic

* Modeled a distance-based RPI concept as well as a trajectory-based RPI-like concept - Concepts modeled in a flexible manner, so that different controller model and trajectory or aircraft models could easily be substituted * Performed simulation studies of impact of two RPI concepts on simulated controller performance in establishing inter-aircraft spacing at merge points of converging route networks - Metric: percentage of flights that required vectoring * Focused examination on impact of control horizon, characteristics of the demand level, nominal separations, and winds - Also examined the effect of multiple consecutive merge points