GNSS Measurements Update - European GNSS Agency
GNSS Measurements UpdateGNSS Raw Measurements from Android PhonesGSA Raw Measurements Workshop, Prague, 30 May 2018v1.02Frank van DiggelenGoogle
What if we had one meter accuracy inphones?Lane-level vehicle navigationPedestriannavigationWhat’s the fastest routeusing carpool lanes?Which side of the road am I?2
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What if we had centimeter accuracy from aphone?You may know this as:“Differential GPS”“PPP” or “RTK”GPS signal is a tape measure,With tick-marks labeled every 300mReferenceGPSImage credit: “GPS, Signals, Measurements, and Performance”, P. Misra, P. Enge, 2001.
Dual Frequency .Today all smartphone GPS/GNSS is on one frequency band: L1.L5 is a new frequency band supported by these GNSS systems:GPS, Galileo, BeiDou, QZSS, IRNSS.Second frequency fasterconvergence to carrier-phaseaccuracy.
Sample applications umerAtmosphereGNSSD-GNSSJammer oSig ProcessingGISNMA a patternsMappingRx ClockWalking NavLandscapingGeocaching7
Measurements, Tools and Analysis1. Raw GNSS Measurements2. Logging and Analysis Tools3. What’s new in 20184. Hands-on exercises5. Future: apps and research Google 20188
Location APIs, Measurement APIsaka Google Play ServicesMost Android phones have this (not China)Location APIs, android.gms.location Places Geofencing Fused Location Provider (FLP) Fit Activity Recognition NearbyAll Android phones have thisMeasurement/Sensor APIs, in android.location Location GnssMeasurementGNSS Raw Measurements GnssClockAll phones with:GNSS chips build date 2016OS Android N (Nougat) Google 20189
https://g.co/GnssToolswhich phones have GNSS Raw Measurements: Google 201810
Logging and Analysis ToolsGNSS LoggerGNSS Analysis Google 201811
Logging the raw data on your phone:1,2,3,4.Google Drive Google 201812
Logged Data is stored locally, on the phone: Google 201813
Phone:What’s newin 2018 Duty Cycling control Analysis on phoneDesktop L5/E5 Mission Planning C/No comparison of different phones Error analysis for moving receiver Smoothed and Raw pseudoranges Log of derived data Iono & Tropo control Google 201814
Duty cycling control,For continuous carrier phaseIn Android P:developeroptionFull GNSS, track all available GNSS,with no duty cycling
Analysis on AndroidOn the phone
L1-only L1, L5 C/NoAntenna/filter loss at L5Simulated measurement data to illustrate functionality of toolsMinimum C/No with 0 dBi RHCP antennawith 2dB Front End Noise FigureFrom ICDs for GPS and GalileoGPS (dB.Hz)GAL (dB.Hz)L1/E145.547L5/E5a (I Q)4949L5/E5a (I only)4646
Mission PlanningNew feature: see where all the GNSS satellites are, at any time, from any place
C/No comparisonfrom different phones
Measurement error for moving receiver
Plots from raw and smoothed pseudorangesSimilarly for WLS (Weighted Least Squares) position plots
Log file of derived data
Iono & Tropo control
Hands-on exercises1./GnssAnalysisFiles/demofiles/ 2./GnssAnalysisFiles/driving/ 3.The demo log file you downloaded with the desktop appWe will use this to learn the capabilities of the analysis toolsGPS dual-frequency log file with ground-truth nmeaUse this to analyze reflections in urban canyons./GnssAnalysisFiles/ionotropodemo/ GNSS log file, stationary, at a known position, open skyExample of how to analyze iono and tropo errors. Google 201824
Exercise ts Google 201825
Download log files for the following torial Google 201826
Exercise #2./GnssAnalysisFiles/driving/ Google 201827
Analysis example, driving into San Francisco:28Source: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis non erat sem
Analysis example, driving into San Francisco:Low satelliteG22PR Error 50m-10 dBWhat happened with satellite G22?29Source: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis non erat sem
Exercise #31.2.3./GnssAnalysisFiles/ionotropodemo/Use true position for Reference PVTSelect highest satelltes to use for clock bias computation (CustomParam.txt)Remove iono and tropo model from analysisThen error plot will show all errors relative to the highest satellites. Google 201830
How to get true position from Google Earth (1)Preferences Show Lat/LongDecimal DegreesUnits of MeasurementMeters,KilometersTerrainUse high quality terrainUse 3D imagery Google 201831
How to get true position from Google Earth (2)hG height above Geoid,from Google Earth 3D Buildings, 20mhS height of stand 1mdE -32, Ellipsoid - GeoidhE hG hS dE 20 1-32 -11 m.Rooftop true position: 37.421568, -122.085429, -11m Google 201832
CustomParam.txt%Currently supported:%param.losSvid list of svid to use for computing clock (Bc and BcDot)%template for losSvid.Svid: must have .FreqBand, .Constellation, .IdSvid1.Id 32;Svid1.FreqBand GnssConstants.L1 BAND;Svid1.Constellation GnssConstants.GNSS CONSTELLATION GPS;param.losSvid.Svids {Svid1}; %pack in a cell array {}You edit these lines to choose thereference satellite(s) you want.And place this txt file in the samedirectory as your log file. Google 201733
Analyzing,errors:iono tropo SIS11SISerrors Signal In Space errors errors after applying broadcast ephemeris and clock values Google 201834
Google 201835
Google 201836
Future: examples of apps and research1.2.3.4.Jamming detectionCarrier-phase PVTGNSS system monitorSignal analysis (iono, tropo, SIS, multipath, radio noise) Google 201837
1) Jamming detectionSample datacollected live on anAndroid O testdeviceAlternating values?AGC levels are specificto the hardware, so youcan’t read too much intothe details, but thetrends are useful.Jammer source operatingmicrowave ovenDevice in frontDevice by the door edge Google 201838
2) Carrier phase AccumulatedDeltaRangeADR is continuous only when clock is continuous, and there is no duty cycling Google 201639
Apps for high-accuracy GPSHigh tionlibraryL1 “PPP” 1maccuracy aftera few minutesconvergence.GNSSMeasurementsGNSS HAL & FrameworkGPS/GNSSchipReferenceGPSPPP Precise PointPositioningPublic sources for code libraries and reference networks:www.rtklib.org, RTKLIB: An Open Source Program Package for GNSS Positioningwww.igs.org, International GNSS ServicePPP Wizlite, from CNES
3) Decoded Nav data, in GnssLogger:And in log file:## Header Description:## Version: 1.4.0.0, Platform: N## -104Decimal equivalent of each byte, for example: 0b00111111 63 Google 201741
4) Signal analysis: iono, tropo, SIS, multipath, and radio noise:Average C/Noσ (pseudorange errors)46 dB.Hz5.4 m37 dB.Hz9.2 m30 dB.Hz18.2 m42Source: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis non erat sem
Summary Get raw measurements from Android phonesDetails and software at https://g.co/GnssToolsMuch analysis you can do with the tools directlySave derived data, and do further analysis with itPursue research, teaching, testing and app development based on thesemeasurements43Source: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Duis non erat sem
Proprietary ConfidentialEnd,Thank you.44
Atmosphere GNSS D-GNSS Jammer detection Monitoring: Sports Iono RF RTK/PPP Weather Data Golf Tropo Sig Processing GIS Accuracy Drones NMA (Auth.) Orbits Surveying Antenna patterns Mapping Rx Clock Walking Nav Landscaping Geocaching
Oct 15, 2017 · GNSS 5 click - board with NEO-M8N GNSS receiver module from u-blox MikroElektronika Subject: Determine your current position with GNSS 5 click. It carries the NEO-M8N GNSS receiver module from u-blox
Unlike conventional inertial navigation systems, the RT uses GNSS to correct all its measurements. GNSS makes measurements of position, velocity and (for dual antenna systems) heading. Using these measurements, the RT is able to keep other measurements, such as roll and pitch, accurate. Tight coupling of the GNSS and inertial measurements
GSM/GPRS/GNSS HAT User Manual 1 / 32 GSM/GPRS/GNSS HAT User Manual OVERVIEW This is a handy, low power Raspberry Pi HAT which features multi communication functionalities: GSM, GPRS, GNSS and Blueto
CONTENTS xi 6.3.1 Basic Principles 466 6.3.2 GNSS-ROInstruments 472 6.3.3 GNSS-ROApplications 473 6.4 Global Navigation Satellite System-Reflectrometry 476 6.4.1 BasicPrinciples: GNSS-Ras aMultistatic Radar 478 6.4.2 GNSS-RParticularities 485 6.4.3 Thermal Noise, Speckle, and CoherenceTime 489 6.4.4 GNSS-RInstrume
Android raw data measurements are obtained through the use of the ’Android.location’ API [5]. Within this API, a public class called GnssMeasurement contains GNSS data supposedly coming directly from the embedded chipset. This class is divided into two data groups. The first one, called ’Public methods’, regroups all GNSS raw data .
analyzing dual frequency precise point positioning single or combined GNSS system (GPS, GLONASS, Galileo and BeiDou). Extra visual components and . focus of this study is the post-processing the GNSS data observations from each of the GNSS constellation (GPS, GLONASS, BeiDou, and Galileo). In addition,
4 Market Overview and Trends 13 4.1 Market Evolution and Key Trends 13 4.2 Main Market Players 14 4.3 Main User Groups 15 5 GNSS User Requirements Analysis 16 5.1 GNSS Use for Timing & Synchronisation 16 5.2 Prospective Use of GNSS in Timing & Synchronisation 23 5.3 GNSS Limitat
business,insurance risk transformationor activities directly arising frominsurance risk transformation(for example,general insurance businessoraccepting deposits) thefirmmay choose to comply with Principles6, 7, 8 and 9 as if all itsclientswerecustomers. Alternatively, it may choose to distinguish betweeneligible counterpartiesandcustomersin complying with thosePrinciples. If it chooses to .
