1-4-2 
referenced to the used taxiway. The second possibility is only procedures for the air navigation data are established. The 
available if the plane position is referenced to have a digital technical solutions for interfaces to up-date or renew the database 
(vector) map of the airport. are less problematic, than the setup of the information flow from 
the original source for changes to the onboard map. 
1.2 Aircraft based information requirements 
The existence of a digital map lead to a key technology used in 
car navigation for several years. 
Pilot assistance systems have the functionality to give navigation 
information while the pilot himself is responsible for driving. The 
requirements to the man-machine-interface (MMI) are very high, 
due to the fact, that during the landing the pilot is supported by 
systems that had been improved for several decades. For this 
risky phase of the flight huge amounts of money were invested to 
improve the MMI and in consequence the flight safety. 
Nevertheless today the pilot still depends on paper maps and his 
capability to read these maps while driving the plane. This will 
grow in future to a risk factor, if the time slots for the aircraft on 
an runway or taxiway are reduced from two minutes down to one 
minute for example 
Automatic Driving of an aircraft with a reliable navigation 
system and a reliable digital map in use seems to be more an 
organizational problem than a technical one. The key to get into 
this technique is nevertheless the reliability and safety of the 
technical systems and the information stored in the database. 
Safety requirements and safe information systems for traffic 
operation systems lead to new data acquisition technologies in 
geodesy. 
2 REQUIREMENTS TO THE DATABASE 
In this paper the requirements of the pilot assistance system 
TAGSY is in this paper concentrated on the digital map. More 
than the geometric accuracy the topological correctness of the 
taxiway network is important for all applications of this database. 
The topological model must include besides the geometric 
topology a complete model of the traffic on this network. 
The up-to-dateness is the next important requirement to the 
database. In the Aeronautical Information System up-to-dateness 
3 EXISTING DATA STRUCTURES 
In the geo-information market some data structures for geodata 
were developed. Beside the software producers of geo 
information systems the surveying administration and the 
electronic industry producing navigation systems pushed the 
development of standards forward. In the mid eighties the 
standards were close together, due to the fact that in the EU 
project ’’Task Force European Digital Road Map” a conceptual 
data model was agreed on. This took into consideration the 
DIGEST (Military Standard), ATKIS/NTF (Surveying 
Administration), GDF (Car Navigation ) and RDB (Road 
Administration) 
Picture 2 Conceptual Data Model for Geo Standard 
The development of the standards divagated especially in the 
application depending object definitions. An integrated use is 
quite problematic today. 
3.1 Surveying Administration 
The surveying administrations usually motivated (financed) by 
the military organizations modeled many objects including 
airports. One main aspect of this development was the 
substitution of the topographic map in the strategic planning 
process. One main quality aspect was the completeness of the 
database. In Germany the surveying administrations defined a 
restricted set of attributes to be captured in the first step in the 
ATKIS-Specification . In a second turn, about five years later, the 
next step in density of information was done. 
The quality of up-to-dateness of this databases will be improved 
when the administration will realize the next step of the 
development, a continuous maintenance of the databases. 
3.2 Car Navigation 
The data structure of the databases created for car navigation 
included not only geometric objects. This data model represent