Simplified dynamic density: A metric for dynamic airspace configuration and NextGen analysis

The next generation air transportation system (NextGen) is expected to bring about major improvements in both airspace design and utilization. One element of NextGen, dynamic airspace configuration (DAC), is proposed as a means to facilitate substantially more efficient airspace capacity management. A new metric or set of metrics is required for analyzing future airspace design concepts like DAC. These metrics are likely to replace the current operational index of workload (i.e., monitor alert parameter, or MAP). The new metric(s) should be able to accommodate various operational concepts and their associated airspace designs. Toward this end, we have developed a multi-component metric, simplified dynamic density (SDD), whose component weightings can be adjusted to the relevant situational characteristics created by various operational concepts. The value of this metric, as evidenced by the current study, is that (a) it can be computed from a single input file containing flight-planned trajectories such as ETMS ldquoFZrdquo records; (b) in addition to calibration against controller workload in real-time human-in-the-loop simulations, it can be ldquoself-calibratedrdquo using historical data and certain reasonable assumptions on sector workload in today's airspace; and (c) it can be applied successfully to trigger DAC actions, thereby optimizing airspace use. With continued development and use of SDD it should be possible for the research community to better understand NextGen concepts and their impact on the workload of the ATM operational community.