Table Of ContentDigital Satellite Navigation and Geophysics
Bridge the gap between theoretical education and practical work experience with this
hands-on guide to GNSS. A clear, practical presentation of GNSS theory is provided,
with emphasis on GPS, GLONASS, and QZSS, together with the key applications in
navigationandgeophysics.
Whetheryouareapracticingengineer,aresearcher,orastudent,you’llgainawealth
ofinsights from theauthors’25years ofexperienceintheGNSS field. You’ll also get
hands-on user experience with a bundled real-time software receiver and signal simu-
lator,enablingyoutocreateyourownGNSSlabforresearchorstudy.
Numerous practical examples and case studies are provided, which you can explore
usingtherealsignaldataprovidedorgeneratedbyyouusingthesignalsimulator.Also
covered are issues related to GNSS signal propagation and its use in geophysics,
including ionosphere mapping, atmosphere monitoring, scintillation measurements,
earthquakeprediction,andmore.
Ivan G. Petrovski works on GNSS applications development at iP-Solutions, Japan.
He has been involved in the GNSS field for more than 25 years. Prior to working at
iP-Solutions,heworkedasAssociateProfessorwithMoscowAviationInstitute(MAI),
asJapanScienceandTechnologyAgency(STA)FellowwithJapanNationalAerospace
Laboratory (NAL), directed the Institute of Advanced Satellite Positioning in Tokyo
University of Marine Science and Technology (TUMST), and led GNSS-related R&D
for DX Antenna and GNSS Technologies Inc. He received his Ph.D. in aerospace
navigationfromMAIin1993.
ToshiakiTsujiiistheHeadofNavigationTechnologySection,AviationProgramGroup,
at the Japan Aerospace Exploration Agency (JAXA), where he has been investigating
aspects of satellite navigation and positioning for more than 20 years. He was at the
Satellite Navigation and Positioning (SNAP) Group, University of New South Wales,
Australia,asavisiting research fellowfrom2000to2002.HereceivedhisDr.Eng.in
appliedmathematicsandphysicsfromKyotoUniversityin1998.
Thisbookprovidesanexcellentintroductiontosatellitenavigationandthetechnologies
thatmakeitpossible.Theauthorssetforthbothfundamentalsandpracticalaspectsina
mannerthatallowsevennewcomerstoGNSStoutilizeiteffectively.Thetopicscovered
inthisbookaddressthemostimportantelementsofcurrent-dayGNSSapplications.
SamPullen,StanfordUniversity
Digital Satellite Navigation
and Geophysics
A Practical Guide with GNSS Signal Simulator
and Receiver Laboratory
IVAN G. PETROVSKI
iP-Solutions,Japan
TOSHIAKI TSUJII
JapanAerospaceExplorationAgency(JAXA)
cambridge university press
Cambridge,NewYork,Melbourne,Madrid,CapeTown,
Singapore,SãoPaulo,Delhi,MexicoCity
CambridgeUniversityPress
TheEdinburghBuilding,CambridgeCB28RU,UK
PublishedintheUnitedStatesofAmericabyCambridgeUniversityPress,NewYork
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©CambridgeUniversityPress2012
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Firstpublished2012
PrintedintheUnitedKingdomattheUniversityPress,Cambridge
AcataloguerecordforthispublicationisavailablefromtheBritishLibrary
LibraryofCongressCataloguinginPublicationdata
Petrovski,IvanG.,1962–
Digitalsatellitenavigationandgeophysics/IvanG.Petrovski,ToshiakiTsujii.
p. cm.
Includesbibliographicalreferencesandindex.
ISBN978-0-521-76054-6(hardback)
1. GPSreceivers. 2. Radio–Transmittersandtransmission. 3. GlobalPositioningSystem.
4. Radiowavepropagation. 5. Electronicsingeophysics. I. Tsujii,Toshiaki. II. Title.
TK6560.P4854 2012
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Contents
Foreword pageix
Preface xiii
1 Methodsofpositioningwithnavigationsatellites 1
1.1 Globalandregionalsatellitenavigationsystems 1
1.2 Positioningtasksinnavigationandgeodesy 6
1.3 Referencecoordinatesystems 8
1.4 Timeframeandtimekeeping 15
1.5 Accuracy,precision,andnormaldistribution 16
1.6 PrincipleofpositioningwithsatellitesandGNSSequations 19
1.7 TaylortheoremandlinearizationofGNSSequations 23
1.8 Leastsquareestimation(LSE) 24
1.9 Integritymonitoring 30
1.10 EssentiallynonlinearproblemsofpositioningwithGNSS 32
References 35
2 PresentationsandapplicationsofGNSSorbits 37
2.1 Developmentofmodelsforcelestialbodymovementsfrom
PtolemytoEinstein 37
2.2 OrbitalmovementdescriptionbyKeplerianparameters 42
2.3 OrbitimplementationinGPSnavigationmessage 47
2.4 EphemeridesofGNSSsatellites 48
2.5 Tabularorbits 51
2.6 Satelliteclocks 55
2.7 ApplicationofKeplerianalmanacforconstellationanalysis 56
2.8 Forcemodels 61
2.9 Wheredoallthesatellitesgo?Asatellitelifecycleandspacegarbage
hazards 63
References 64
Exercises 66
vi Contents
3 GNSSsignalgenerationintransmittersandsimulators 67
3.1 Spread-spectrumradiosignalsforsatellitenavigation 67
3.2 GNSSsignalsimulator 81
3.3 Casestudy:scenariodatagenerationforairbornereceiver 86
3.4 DIFsignalgenerationinGNSSsimulator 95
3.5 RFsignalgeneration 97
3.6 Project: GPS signal simulation with bundled ReGen simulator
version 100
References 102
Exercises 103
4 Signalpropagationthroughtheatmosphere 104
4.1 Geometricalopticstheoryofradiosignalpropagation 106
4.2 GNSSraybendingintheEarth’satmosphere 108
4.3 GNSSsignalphaseandgroupvelocityintheionosphere 110
4.4 GNSSmodelsofpropagationintheionosphere 113
4.5 Propagationinthetroposphere 122
4.6 Modelingatmosphericerrorsinareceiverandinasimulator 124
4.7 Project 125
References 126
5 ReceiverRFfrontend 127
5.1 RFfrontendforsoftwareGNSSreceiver 127
5.2 Antenna 131
5.3 Front-enddesign 139
5.4 Front-endclock 139
5.5 Down-conversion 145
5.6 Analog-to-digitalconversion 146
5.7 Project:recordingliveGNSSsignalstoPC 150
References 153
Exercises 154
6 Real-timebasebandprocessoronaPC 155
6.1 Doweneedallthereceiverorjustabasebandprocessor? 155
6.2 Operationingeneral 157
6.3 Acquisition 159
6.4 Trackinginasoftwarebasebandprocessor 166
6.5 TrackingandacquisitionofotherGNSSsignals 175
6.6 Lockdetectors 176
6.7 Bitsynchronization 178
Contents vii
6.8 Measurements 179
6.9 Real-timeimplementation 180
6.10 Project 182
References 183
Exercise 183
7 Multipath 184
7.1 Multipatherroranditssimulation 184
7.2 Casestudy:multipatheffectonBPSKandBOC(1,1)signals 187
7.3 Multipathmitigation 193
7.4 Project:investigationofmultipatheffectsonreceiverperformanceusing
multipathsimulation 194
References 195
8 OptimizationofGNSSobservables 196
8.1 ErrorbudgetofGNSSobservables 196
8.2 Formingobservables 197
8.3 Multi-frequencyobservables 203
8.4 Improvingobservableswithaugmentationsystems 205
8.5 Project:simulationdataforLAAS 219
References 220
Exercise 221
9 Usingobservablesinnavigation-relatedtasks 222
9.1 Precisepositioningwithcarrierphaseobservables 222
9.2 Casestudy:aircraftattitudedetermination 232
References 239
10 ElectromagneticscintillationofGNSSsignal 241
10.1 Ionosphericirregularities 242
10.2 Rytovapproximationforweakscattering 246
10.3 Scintillationmonitoring 250
10.4 Casestudy:scintillationproducingareaswithdepletedionization 254
10.5 Characteristicsoftheexperimentallyderivedscintillationdata 259
10.6 Phenomenologicalmodelforweakscintillation 263
10.7 Split-beamscintillationmodel 265
10.8 Project:ionosphericscintillationsmonitoringwithaniPRxreceiver 266
References 267
Exercises 269
viii Contents
11 GeophysicalmeasurementsusingGNSSsignals 270
11.1 Ionosphericparametersestimation 272
11.2 Radiooccultationtechnique 273
11.3 Earthrotationparametersestimation 276
11.4 GNSSinearthquakestudy 279
11.5 Casestudy:seafloormonitoringsystem 280
11.6 Earthquakeprecursorsintheionosphere 285
References 289
12 AidingbasebandandnavigationprocessorsusingINS 293
12.1 PrinciplesofGNSSandINSintegration 293
12.2 Casestudy:INSaidingforrobusttracking 294
12.3 Casestudy:INS-aidedtrackingunderscintillationconditions 305
12.4 Precisepointpositioningfordynamicapplications 311
12.5 Project:Processingflightdatawithsoftwarereceiver 315
References 316
Nextstep–RFlab 318
Index 319
Foreword
I built my first crystal radio kit when I was 9 years old. I became hooked on radio
technology,evenatthattenderage,andlaterwentontobuildotherradiosasateenager,
includingashortwavereceiverfromakit.Ilearnedhowradiosworkedbybuildingthemand
tinkeringwiththem.IlearnedmuchlateronthatthefamousAmericanphysicist,Richard
Feynman,alsohadaninterestinradioswhenhewas11or12.Hewouldbuybrokenradios
atrummagesalesandtrytofixthem.That’sthewayhelearnedhowtheyworked.Ashe
saysinthefirstchapter of his bookSurely You’reJokingMr.Feynman!–Adventures ofa
CuriousCharacter,‘Thesetsweresimple,thecircuitswerenotcomplicated...Itwasn’t
hard for me to fix a radio by understanding what was going on inside, noticing that
somethingwasn’tworkingright,andfixingit.’Asweknow,Feynmanwentontounravel
thenatureofquantummechanicsamongstotheraccomplishments.And,allhislife,hetook
greatpleasureinfindingthingsout.
Myinterestinradioandelectronicstogetherwithaloveofphysicsledmeeventually
into a teaching and research career in space geodesy and precision navigation. Over
the years, I have been involved with a number of mostly radio-based space geodetic
techniques.AsaPh.D.student,Iworkedwithverylongbaselineinterferometry(VLBI)
and satellite Doppler (the US Navy Navigation Satellite System or Transit) and as a
postdoctoralfellowatMIT,Iworkedwithlunarlaserrangingdataandwasintroduced
to one of the very first civil GPS receivers: the Macrometer™. Upon arriving at the
UniversityofNewBrunswick’sthenDepartmentofSurveyingEngineeringin1981,it
wasbacktosatelliteDoppler.Butwithinayearortwo,GPScapturedmyattentionandit
hasbeenvirtuallymysoleinteresteversince.
While most of my writing about GPS has been for journals, the proceedings of
technical meetings and GPS World magazine, I was fortunate to be a co-author of one
ofthefirst,ifnotthefirst,textbooksonGPS:GuidetoGPSPositioning,publishedby
CanadianGPSAssociatesin1986.Itwasatechnicalbest-seller,withover12000copies
soldworldwideintheEnglishversionalone.
There have been many advances in GPS technology since that seminal book was
published.Infact,withthealmostsimultaneousdevelopmentoftheRussianGLONASS
satellitenavigationsystemand,morerecently,theinitialdevelopmentoftheEuropean
Galileo system, the Chinese BeiDou/Compass system, the Japanese Quasi-Zenith
Satellite System (QZSS), and a number of satellite-based augmentation systems, we
nowneedtousetheterm‘globalnavigationsatellitesystems’orGNSS.AndGPSitselfis
x Foreword
going through a modernization exercise with the introduction of new signals, new
satellitedesigns,andnewgroundinfrastructure.
Muchofthe researchassociatedwithcurrent developmentsinGNSS ispublished,in
atimelyfashion,intechnicalpapersinjournalsandmeetingproceedings.Butthesepapers,
typically written byexperts for other experts,are often difficult for studentstofollow –
especiallythosejuststartingoutinthefield.Thereisstilltheneedforgoodtextbooksabout
GPSandtheotherGNSS,andthereareseveralcurrentlyinprint.Theydoagoodjobof
explainingthetheoryofhowGNSSworkbutthereareveryfewresourcesmatchingthe
theorytoactualreceiverssothatastudent,forexample,mightlearnbydoingasIdidyears
agowhenlearninghowshortwaveradiosworked.Inpart,thisisduetothefactthatmodern
GNSSreceiversareextremelycomplexdevicesandmostarenotdesignedtobeteaching
tools.
With their new book, Ivan Petrovski and Toshiaki Tsujii have filled this education
gap.DigitalSatelliteNavigationandGeophysics:APracticalGuidewithGNSSSignal
SimulatorandReceiverLaboratoryisnotonlyatextthatclearlydescribesthegeneration
ofGNSSsignalsandhowtheyareprocessedbyareceiver,butitisalsoaccompaniedby
bothaGNSSsoftwaresignalsimulatorandasoftwareGNSSreceiver.Nowitispossible
to learn how GNSS work by doing. After reading about an aspect of signal design,
transmission,propagationorreception,thestudentcansimulateitandseehowareceiver
respondstoit,immediatelyseeing‘causeandeffect.’
Theuniquenessofthebookisrevealed,inpart,bythewordsinitstitle.Let’sstartwith
‘digital.’ The authors carefully and clearly describe the generation, transmission, and
receptionofGNSSsignals,whichareinherentlydigital,althoughmodulatedontoradio-
frequency(RF)analoguecarriers.And,inamodernGNSSreceiver,thefrontendincludes
an analogue to digital (A/D) converter that transforms the signal to baseband where it
canbemanipulatedinatotallydigitalway.Theauthorsthoroughlydiscussthegeneration
of GNSS signals in the satellites and in signal simulators, as well as the operation of
thereceiver’sRFfrontend,includingA/Dconversion,andbasebandprocessing.Notonly
arethelegacyGPSsignalsfullydescribed,butalsothoseofmodernizedGPS,GLONASS,
QZSS,andGalileo.
Then‘satellitenavigationandgeophysics.’GNSSuserscanbeverybroadlyclassified
intotwogroups:navigatorswhosepositioningneedscanbemetbyusingpseudorange
measurements on one frequency to achieve metre-level accuracies and high accuracy
users, including surveyors, engineers and scientists who make use of the more precise
carrier-phasemeasurements(inadditiontopseudoranges),typicallyontwofrequencies.
Positioningaccuracyatthecentimeter-levelorbetterisoftenthegoal.Theauthorsnot
only describe the various aspects of GNSS for navigation, but also for the more
demanding applications including some of those in geophysics. The use of GNSS for
ionosphericscintillationmonitoring,formeasuringEarthrotationandassessingtectonic
platemotionarealldiscussed.
Andfinally‘practicalguide.’TheauthorspresentnotonlythetheoryofhowGNSS
signals are generated and processed under ideal conditions, but also how a receiver
responds to various real-world effects such as ionospheric disturbances and multipath.
Andtheseandotherfactorscanbestudiedwithahands-onapproachusingthesoftware
