Virtual Tower (Acronym ViTo) is the vision of a future control center for airport ground traffic management (including approach and departure) without the direct far view out of tower windows, i.e. without the necessity of an exposed tower building.
In 2002, as a result of the 2001 Visionary Projects competition, DLR launched the initial ViTo concept study. ViTo represents an extension of Advanced Surface Movement Guidance and Control Systems (ASMGCS), by emphasizing the importance of the visual surveillance component.
This fact is derived from a number of tower work and task analysis studies and is stated by IFATCA, the International Air Traffic Controllers Association, as the "sine qua non" for any Virtual Tower Concept. Advanced sensing and visualisation technologies today open the possibility to reconstruct the real view out of tower windows and present to the tower controller an artificial live view which is comparable to the real one. Additional features included in such a system are e.g. video based binocular function by remotely controlled Pan Tilt Zoom cameras with automatic tracking function and continuous storage of full day traffic histories allowing for the replay of abnormal events.
In close cooperation with Germany's Air Navigation Service Provider "Deutsche Flugsicherung (DFS)" requirements were defined which led to intermediate steps on the way to the ViTo goal: Augmented Tower Vision (ATV) and Remote Tower Operation (RTO) for small airports. The latter one led to the DLR project RapTOr (Remote airport Tower Operation research, 2005-2007) and the follow-up project RAiCe (Remote Airport tower control Center, 2008 -20012); the former goal led to concepts of using Virtual and Augmented Reality technologies for improving the controller's situational awarenes, e.g. by decreasing head-down times through superimposition of flight and weather data on the high resolution video reconstruction.
Formal Models of decision making
The human centered ViTo, RTO and RAiCe HMI-design methodology is based on work and task analyses which provide input data for formal models of the (traffic) process, perception, human system interaction, and decision making. Within the projects corresponding modeling tools have been developed based on colored Petri nets and dynamical systems theory which are verified and validated, e.g. by means of experiments in simplified microworld airport traffic environments.
Because the Virtual Tower airport traffic control center may be located anywhere in the airport vicinity, even in a remote location, it provides new oportunities for collaborative decision making with other agents engaged in the traffic management task, like airport operator and airlines.