GPS World, April 2015
April 2015 VOL 26 NUMBER 4 gpsworld com COVER STORY GALILEO SPECIAL SECTION GNSS MODERNIZATION Galileo E1 and E5a Performance 30 For Multi Frequency Multi Constellation GBAS Analysis of new Galileo signals at an experimental ground based augmentation system GBAS compares noise and multipath in their performance to GPS L1 and L5 Raw noise and multipath level of the Galileo signals is shown to be smaller than those of GPS Even after smoothing Galileo signals perform somewhat better than GPS and are less sensitive to the smoothing time constant By Mihaela Simona Circiu Michael Felux and Sam Pullen EXPERT ADVICE Taking Up Positions Galileo and E112 28 By Andy Proctor 2015 GNSS MARKET REPORT European GNSS Agency Provides a Fresh Look at Worldwide Growth 36 The report presents an overview and quantification of the GNSS market of today and the future It specifically looks at the global GNSS market in terms of shipments revenues and installed base of receivers with a forecast up to 2023 GALILEO PRODUCT SHOWCASE 39 OPINIONS DEPARTMENTS Out in Front 6 The Things We Carry By Alan Cameron THE SYSTEM 8 GPS IIF 9 Launch Celebrating 20 Years and more THE BUSINESS 12 Mobile World Congress Report Rohde Schwarz Adds Testing FAA Seeks Comments on UAS and more EXPERT ADVICE The Impact of RFI on GNSS Receivers 50 By Fabio Dovis INNOVATION Carrier Phase Ambiguity Resolution 42 Handling the Biases for Improved Triple Frequency PPP Convergence Precise point positioning PPP can be considered a viable tool in the kitbag of GPS positioning techniques One precision aspect of PPP is its use of carrier phase measurements rather than just pseudoranges But there is a catch Often many epochs of measurements are needed for a position solution to converge to a sufficiently high accuracy In this months column we look at how using measurements from three satellite frequencies rather than just two can help By Denis Laurichesse www gpsworld com April 2015 GPS World 3
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