34TH ANNUAL CONFERENCE, Jerusalem, Israel, 27-31 March 1995
WP No. 104
Presentation of ADS Data to the Controller
An ADS-ATC system offers potential benefits to the air traffic service provided, by making available data to the control team which is near continuous. The quality of this data is greatly enhanced over non-radar control because it is derived directly from airborne systems, as is the range and timeliness of flight data available.
The way that this data is used will thus provide the benefits of flexible routings, and greater tactical freedom in the control task. It is important to present this data in a way that supports the controllers tasks.
Presentation of ADS data
Non-radar control, which ADS may replace in some areas of the globe, presents flight data in effectively a tabular format upon flight progress strips. The route of flight of an aircraft has to be interpreted from the strip route fields, and a mental model built by the human which models the domain. As routes become more complex and the traffic grows, so the cognitive workload in maintaining situational awareness and the mental model grows. The humans ability to accommodate flexible tracks and to perform the complex conflict detection and resolution calculations for traffic which requests a non standard route becomes therefore increasingly constrained as traffic density grows.
The volume of data that is available to the controller in an ADS environment is much greater. In order to utilise this data in a way which enables the system to be responsive to the needs of aircraft operators, it therefore needs to be presented in a way which enables the cognitive workload of the controller to be reduced and at the same time enhancing the situational awareness of the controller.
The most effective presentation is to use some means of graphic presentation. Such a display therefore will likely take on the appearance of a conventional radar display. The use of such displays is as yet to be proven, in particular the judgement of separations between aircraft, similar to the way that radar controllers use such displays, over such potentially large geographical areas may require system assistance.
It can be envisaged that planning tools may be designed which enable the controller to construct routes on screen to test tactical plans, and to present the flexible route that particular aircraft requests. In effect there is the potential for a random route structure within a particular ADS airspace. Such a development must ensure that the displays enhance the controllers situational awareness and not degrade it.
The data displayed on such a display must be useful and related to the particular requirements of the control task. The risks of overloading the human by the sheer volume of information that are high. The distinction must be drawn between information – which is there but not of any use, and data – useful information with a specific task related purpose.
A limitation in many human machine systems is the interaction between human and the machine. If human machine interface is not designed with due regard for the human in the system, workload can increase such as to negate any benefits in capacity.
The display of ADS data to the controller is an important factor in the efficiency of the operational system. Whilst tabular data is used in non-radar control, this presents the data to the controller in a cumbersome way which can hinder the ability of the human to build and retain mental models and the degree of situational awareness likely. Graphic or pictorial displays are the most suitable way to present ADS data, in conjunction with supporting data displays.
Care must be exercised to provide pertinent and relevant data to the controller rather than cognitively overloading the controller with information.
The workload of both the controller and pilot can be increased by inappropriate or cumbersome interfaces with ADS supporting systems. Therefore interaction with ADS support systems must not add to controller or pilot workload.
It is recommended that:
Graphical or pictorial displays, in conjunction with supporting data displays of ADS data, should be provided to enable the controller to carry out the control tasks.
Only pertinent and useful flight data should be supplied to the control team which supports and enhances the building of human mental models and controller situational awareness.
System design must seek to optimise the interface, at the controller workstation.
Last Update: September 28, 2020