Table of Contents
International Journal of Navigation and Observation
Volume 2008, Article ID 651437, 8 pages
Research Article

Joint L-/C-Band Code and Carrier Phase Linear Combinations for Galileo

1Institute of Communications and Navigation, Technische Universität München (TUM), Theresienstraße 90, 80333 München, Germany
2German Aerospace Center (DLR), Institute of Communications and Navigation (IKN), Münchner Straße 20, 82234 Weßling/ Oberpfaffenhofen, Germany

Received 1 August 2007; Revised 27 November 2007; Accepted 15 January 2008

Academic Editor: Gerard Lachapelle

Copyright © 2008 Patrick Henkel and Christoph Günther. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Linear code combinations have been considered for suppressing the ionospheric error. In the L-band, this leads to an increased noise floor. In a combined L- and C-band (5010–5030 MHz) approach, the ionosphere can be eliminated and the noise floor reduced at the same time. Furthermore, combinations that involve both code- and carrier-phase measurements are considered. A new L-band code-carrier combination with a wavelength of 3.215 meters and a noise level of 3.92 centimeters is found. The double difference integer ambiguities of this combination can be resolved by extending the system of equations with an ionosphere-free L-/C-band code combination. The probability of wrong fixing is reduced by several orders of magnitude when C-band measurements are included. Carrier smoothing can be used to further reduce the residual variance of the solution. The standard deviation is reduced by a factor 7.7 if C-band measurements are taken into account. These initial findings suggest that the combined use of L- and C-band measurements, as well as the combined code and phase processing are an attractive option for precise positioning.