GPS World, October 2018

Fraunhofer IIS 1 09 08 07 06 05 04 03 02 01 the POINT software FIGURE 14 compares the RMS of the horizontal errors with the IF configuration Less than a minute after the receiver lost lock on the satellites the solution reconverged below the 20 centimeter level while it took less than 30 seconds to go below 50 centimeters CONCLUSIONS In this article we described a comparison that we carried out between GPS only Galileo only and GPS plus Galileo PPP Results based on simulated open sky conditions demonstrated that Galileo performs better than GPS thanks to an assumed lower E1 E5a IF noise with respect to L1 L5 Two constellation PPP enables faster re convergence compared to the single constellation case An analysis of GNSS signal availability continuity and satellite geometry was also performed to study the feasibility of PPP in urban environments Preliminary results based on simulations showed that dualconstellation GPS plus Galileo PPP is possible in urban areas with relatively short buildings in which a satellite minimum availability requirement is met most of the time However signal discontinuity still represents the major problem for traditional PPP in urban environments due to long reconvergence times Finally we proposed a new PPP configuration based on triplefrequency combinations intended to minimize the noise on the pseudorange and corrected by a smoothed ionospheric delay This configuration seems to provide faster reconvergence than the traditional PPP with the IF combination if applied to kinematic scenarios In static applications the very slow varying multipath error makes the proposed weighting method based on the error in the smoothed ionosphere correction overly optimistic In such cases the IF combination reconverges more quickly to high accuracy levels better than 20 centimeters 90 100 110 120 130 140 150 160 170 Time minutes 0 RMS horizontal error meters L1 L2 IF Low noise combination Smoothed iono 180 FIGURE 13 RMS error of horizontal position component of static site using GPS data after filter restart with 1 minute multipath time constant The Locating Company GNSS RECEIVER WITH OPEN SOFTWARE INTERFACE GOOSE Main Benefits Flexible development platform with multi system and multi signal real time processing Integrated antenna receiver combination smart antenna Guaranteed stable phase center for all GNSS frequencies Deployment in commercial PC or as an embedded platform Allows deep coupling and vector tracking in real time Access to correlation values GOOSE Technology licensed by Fraunhofer IIS Distributed by TeleOrbit GmbH Performance Parameters 60 hardware channels Up to 25 Hz raw data output code carrier navigation data Supported signals GPS L1CA L2C L5 Galileo E1B E5ab E5AltBOC E6 optional SBAS EGNOS optional BeiDou B1 GLONASS G1 G2 ready Open GNSS Receiver Protocol OGRP 10 MHz reference input and output 1 PPS out 12 ns with a 1 PPS out rise time 3 ns Tracking down to 30 dbHz Acquisition from 35 dbHz www teleorbit eu en GOOSE ESA P Carril 36 GPS WORLD WWW GPSWORLD COM OCTOBER 2018