Revised Combined Galileo/GPS Frequency and Signal Performance Analysis

Abstract

After the agreement between the European Union and the United States of America on the promotion, provision and common use of the two satellite-based navigation systems GPS and Galileo, a new world of possibilities in satellite navigation has opened. On June 26th, 2004 and after long negotiations, the United States and the European Union agreed on the core of the Open Service (OS) signals to be transmitted by Galileo and the future GPS on L1. Since then, an important effort and a lot of work has been made on the European side to find new potential signals that would clearly outperform BOC(1,1) and still be within the terms of the signed Agreement. Especially critical were again the requirements on spectral isolation with the M Code and PRS that the optimised signal must fulfil. The result of all the investigations carried out in the last months has been a candidate optimized signal for L1 OS [1]. The signal proposed by the Signal Task Force (STF) of the European Commission (EC) shows a clear improvement in terms of positioning performance while no great modifications on the payload are needed. Additionally, any BOC(1,1) receiver will be able to receive the new signal, assuring the backward compatibility with the current baseline. The objective of this paper is to show the potential performance enhancement of the combined and independent use of Galileo and GPS signals in terms of positioning accuracy and navigation solution. Combined Galileo and GPS receiver solutions will be proposed and analysed.