Air Traffic Management Tutorial page 9

9. Decision Support Tools
NASA and the FAA have and continue to develop decision support tools that provide controllers with more accurate predictive information about local and national traffic flow, weather and routing. Collaborative Decision Making (CDM) is a term that has very broad implications. It is really more a philosophy on how to conduct business between the various components of aviation transportation within both government and industry. There are 24 airlines currently participating in this initiative. CDM is a specific FAA program, managed by AUA-500 and sponsored by the ATCSCC. There are two central principles to CDM:

As decision support tools become increasingly more sophisticated, the management of air traffic will become even safer than ever before. Below are four such decision support tools that are currently being developed or tested by NASA and the FAA.

Central Altitude Reservation Function (CARF)
The Central Altitude Reservation Function (CARF) supports United States peace and war plan objectives and other special activities. The CARF is responsible for coordinating military and civilian altitude reservations for operations within the NAS.

CARF personnel must be able to determine when military operations, national security aircraft operations, and other civilian emergency operations require special traffic management coordination. CARF is also the coordination point for all Open Skies Treaty Operations.

Enhanced Traffic Management System (ETMS)
While the FAA system is the backbone of the NAS for clearance, control, and monitoring of air traffic, the Enhanced Traffic Management System will significantly improve the efficiency of air traffic management. ETMS automation will assist traffic managers in alleviating congestion, reducing delays, and avoiding traffic flow problems nationwide. The ETMS is an operational, prototype system interfacing people, equipment and procedures.

ETMS is the system used by Traffic Management Specialists to predict, on national and local scales, traffic surges, gaps, and volume based on current and anticipated airborne aircraft. Traffic Management Specialists evaluate the projected flow of traffic into airports and sectors then implement the least restrictive action necessary to ensure that traffic demand does not exceed system capacity. Monitor-Alert, a part of ETMS, analyzes traffic demand for all airports, sectors, and airborne reporting fixes in the continental United States. M/A automatically displays an alert on a controller's screen when demand is predicted to exceed capacity in a particular area. Armed with this information, the Traffic Management Specialist examines the situation then provides spacing and routes to assist in controlling the flow of traffic.

ETMS enhancements are developed by the Advanced Traffic Management System (ATMS), a research, engineering, and development program. Its purpose is to apply new technologies to traffic management problems for inclusion in the next-generation traffic management system. The ATMS program experiments with new concepts and demonstrates their operational feasibility and usefulness for inclusion in the FAA Advanced Automation System.

ETMS takes proven functions from the ATMS prototype development and makes them available for current traffic management operations. As new prototype functions develop, traffic managers evaluate them and provide ATMS managers with feedback concerning functions which may require modification. Once prototypes and their functions are accepted, they are placed into the ETMS system.

ETMS supports traffic managers in measuring traffic demand by showing, on a national scale, current traffic surges, gaps, and volume. It also predicts the flow of air traffic up to 4 hours in advance. Thus, a traffic manager can access destinations, see the projected flow into specific airports or sectors, and take action to ensure that traffic demand does not exceed system capacity for that certain airport or sector.

Traffic Situation Display (TSD)
TSD graphically displays current aircraft positions on a national scale superimposed on maps of geographical boundaries or NAS facilities. It displays all Instrument Flight Rule aircraft and other flights tracked by the 20 Centers. The TSD user can select numerous methods of filtering to highlight groups of aircraft since the system can display all known flights simultaneously or filter out all but a selected group of flights. Aircraft fly on a network of airways. Below 18,000 feet mean sea level (MSL), these are called Victor airways. At and above 18,000 feet MSL, they are designated Jet routes. The TSD can display these complex networks to assist flow management and aircraft routings.

Monitor-Alert (M/A)
The M/A function, available through TSD, is central to ETMS. It compares demand to capacity. M/A analyzes traffic demand for all airports, sectors, and airborne reporting fixes in the continental United States. M/A then automatically displays an alert when demand is predicted to exceed capacity in a particular area.

M/A is able to project traffic demand for all airports, sectors, and fixes of interest in the continental United States. It then automatically generates alerts when the projected demand exceeds capacity thresholds. Alerts are provided in visual and aural form.

This example shows alerted sectors in the Kansas City Air Route Traffic Control Center´s (ARTCC) airspace. Armed with this information, the Traffic Management Specialist examines the situation, then provides spacing and routes to assist in controlling the flow of traffic.

Predictions are in 15 minute increments for up to 4 hours into the future. An alerted sector can be isolated and enlarged on the map to display the predicted congestion in greater detail. Traffic management coordinators can review predicted traffic levels and time intervals of concern which are displayed graphically by red and yellow bars representing actual and predicted traffic volume.

If the traffic management coordinator needs more information, lists of all concerned flights, along with their locations and intended flight paths, can be displayed. This new ETMS function assists traffic managers in pinpointing potential traffic problems so they can take action to reduce or eliminate congestion on the airways.

Monitor-Alert provides the traffic management coordinator with a four-step process to display the predicted situation on the TSD screen. First the United States, or any selected area, can be viewed to identify the existing and predicted alert sectors or airports. These are displayed as red (active alert) or yellow (projected alert). The projected alert indicates that the demand is projected to exceed the capacity. Once an alert area has been addressed, the alert color changes to green.

The second step in the process identifies the value of the alert. The screen displays a graphic bar chart that allows the controller to visualize the value of the alert as well as provide the number of aircraft that exceed the capacity. The chart shows green for the capacity of the sector or airport, yellow for the proposed, and red for the active alert. Time is displayed in 15 minute increments.

The traffic management coordinator can then display all of the flights that make up the alert or those projected flights that will cause the demand to exceed the capacity. This allows the traffic management coordinator to visualize the problem, spacing, and routes to assist in establishing the necessary flow control.

Traffic management coordinators may also display a printed report of the aircraft that are affecting the alert which further assists them in their decision making process.

NASA Research
Air traffic controllers depend on airspace automation tools and decision support tools in order to keep up with the heavy workload associated with today's busy skies. This dependence will increase as the volume of air traffic grows. These systems require large amounts of information transfer between aircraft and the ground. However, current aviation communications systems are simply not up to the task of transmitting such high volumes of data.

To address this critical need, researchers at NASA's Glenn Research Center are working on the Advanced Communications for Air Traffic Management Project. The goal is to provide aircraft with wireless, broadband, satellite-based network connections to the ground. The system uses low-profile (less than one inch) phased array antennas that are steered electronically and can be mounted externally with very little additional drag. Tests of the system aboard a NASA DC-8 increased the aircraft's transmission capability by 100 times and reception capability by 1000 times that of conventional communications links.