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Licensed Unlicensed Requires Authentication Published by De Gruyter March 14, 2015

An Innovative Dual Frequency PPP Model for Combined GPS/Galileo Observations

  • Akram Afifi EMAIL logo and Ahmed El-Rabbany


This paper develops a new dual-frequency precise point positioning model, which combines GPS and Galileo observables. The addition of Galileo satellite system offers more visible satellites to the user, which is expected to enhance the satellite geometry and the overall PPP solution in comparison with GPS-only PPP solution. However, combining GPS and Galileo observables introduces additional biases, which require rigorous modelling, including the GPS to Galileo time offset, and Galileo satellite hardware delay. In this research, a GPS/Galileo ionosphere-free linear combination PPP model is developed. The additional biases of the GPS/Galileo combination are lumped and accounted for through the introduction of a new unknown parameter, inter-systems bias, in the PPP mathematical model. It is shown that a subdecimeter positioning accuracy level and 25% reduction in the solution convergence time can be achieved with the developed GPS/Galileo PPP model.

Received: 2014-4-29
Accepted: 2014-9-11
Published Online: 2015-3-14
Published in Print: 2015-3-1

© 2015 by Walter de Gruyter Berlin/Boston

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