This paper, and the following six papers, were presented during the NAV 98 Conference held
at Church House, Westminster, London on 9th and 10th December 1998. A full listing of
the Conference, and how to obtain a copy of the proceedings, is shown on Page 300.
The existing Loran-C and Chayka infrastructure can, with some minor changes, become a
very powerful augmentation system for GNSS (GPS, GLONASS and the future Galileo).
Delft University initially proposed the Eurofix concept in 1989. Although the necessary
modification to the LF navigation systems are minimal, the GNSS user may get significant
benefits from the Eurofix signals in terms of accuracy, integrity and availability. The reason
is the high signal structure, signal propagation, and the operations dissimilarity of both
systems. The broadcast correction and integrity data improves GNSS accuracy down to the
metre level. In this way, the measured Loran-C and Chayka ranges are continuously
updated. Thus, in the case of GNSS signal interruptions, highly calibrated Loran-C/Chayka
may take over the navigation function. Tests carried out in Europe at the Loran-C station
at Sylt (Germany) drew large international attention, leading to further tests in the USA by
the US Coast Guard in 1998. Recently, a Dutch–Russian consortium implemented Eurofix
on the Chayka transmitter at Bryansk (Russia) which is now successfully broadcasting
DGPS as well as DGLONASS correction data. This paper highlights some on-air Eurofix
DGPS performance experiments carried out in Europe and the USA. With all the European
Loran-C and Chayka transmitters modified, Eurofix can be used all over the European
continent. As multiple stations can normally be received simultaneously, the user may locally
apply networked DGNSS, which may reduce spatial decorrelation effects significantly. Post-
processed results of this Regional Area Augmentation System are presented.