Hänsel, F.; Ganzelmeier, L.; Becker, U.; Schnieder, E.:
Mobile Testbed for the Accuracy and Availability Measurement of Satellite Navigation Systems.
In: Möhlenbrink et al., Hrsg.: Proceedings of "Networks for Mobility" (Fovus), S. 30, ''9 2004. Networks for Mobility, 29.09.-01.10.2004, Stuttgart.
Safe operation control in non-guided traffic requires high availability and
reliability of vehicle localisation technology. Normally the accuracy and availability
requirements for vehicle localisation systems can only be met by complex multisensor
systems comprising on-board and trackside components like odometers, gyroscope,
transponder etc. Satellite-based localisation technology has in recent times
been increasingly used in traffic applications, and GPS–based systems are already in
operation. One of the most promising advantages for traffic is the fact that these systems
provide absolute location information without requiring trackside equipment.
However, satellite-based localisation requires the reception of signals from at least
four satellites. But on many tracks or roadways, this visibility prerequisite cannot be
fulfilled because of shadowing effects from the natural environment, buildings etc.
This results in a considerable loss of localisation availability.
At the Technical University of Braunschweig therefore a method has been developed
within the "SATNAB" project, which allows satellite-based localisation using the signals
from a single or two visible satellites. If we suppose a vehicle is travelling on a
known roadway, its position can be determined by processing the current range between
one visible satellite and the vehicle.
This paper gives an overview of the methodologies used in order to analyse satellite
navigation systems in general and satellite-based vehicle localisation systems in detail.
The structure of the used mobile testbed in form of a measurement vehicle is
presented in details. The build up equipment allows qualifying single satellite receivers
up to complete vehicle localisation technologies.
In addition to this detailed description, the intended applications for the further use of
the vehicle are addressed.