SlideShare a Scribd company logo
www.OpenGNSS.org




               OpenGNSS
           www.OpenGNSS.org
        proposes you this course
             free of charge
       OpenGNSS is a project cofinanced by HELILEO (www.
        HELILEO.com), TECNALIA (www. TECNALIA.es), the
      Regional Council of Aquitaine and the Basque government
www.OpenGNSS.org




           How does a GNSS
            receiver work ?
www.OpenGNSS.org                           Summary




     I. General Principle
     II. Solving the problem of navigation
     III. Error correction
     IV. Notions of integrity




                                       3
www.OpenGNSS.org
                                                      Introduction (1/2)




   • GNSS Receivers : GPS, GLONASS, Galileo

   • Application domains : guidance, data synchronization, geodesy

   • Position computing thanks to satellite signal reception time

    Errors to consider:
       • Clock bias
       • Environment (troposphere, ionosphere, multipath)
       • Dynamic (movement / satellite receiver: Doppler effect)
       • Noise




                                                             4
www.OpenGNSS.org
                         Introduction (2/2)


    Functioning scheme




                               5
www.OpenGNSS.org
                                     I. General principle




      a) Pseudo-range computation

      b) Process based upon code measurement

      c) Process based upon phase measurement




                                               6
www.OpenGNSS.org               a) Pseudo-range computation (1/2)




        Receipt channel scheme


                          Receipt channel:          Distance
                          - Correlator
                          -Tracking loop
      Received signal     - Data decoding
                                                    Velocity
                          - Distances computation
                          - Velocity computation

                                                    Navigation data




                                Satellite code




                                                       7
www.OpenGNSS.org               a) Pseudo-range computation (2/2)




  Where c is the speed of the wave in
  the space
        when the wave is received
        when the wave is emitted

   You get then the "pseudo-range"
   + the clock offset errors




                                                  8
www.OpenGNSS.org

              b) Process based upon code measurement (1/3)

  • Each satellite uses a pseudo random
  noise code (PRN code) associated to
  its signal

  • Periodical signal which value is 0 or 1

  • Same signal generated by the
  receiver                      Received signal
                                                         Correlator output
                                      Local signal
  • Use of a correlator

  • Correlation peak= dt (clock bias)




                                                     9
www.OpenGNSS.org

          b) Process based upon code measurement (2/3)




                                          10
www.OpenGNSS.org

             b) Process based upon code measurement (3/3)

    Code pursuit

    • Use of correlators
    (Early, on time, late)

    • Differentiation=feedback
    control loop

    • Ambiguity on measurement,
    simple but not very precise
    and surrounded by noise

    • Phase measurement=>
    precision more accurate



                                             11
www.OpenGNSS.org

                   c) Process based upon phase measurement


   •Measurement of a difference of phase between local signal and
   emitted signal (ambiguity increased)

   •Possibility to combine measurement of code and phase in order to
   combine precision / non ambiguity

   •Difference of phase obtained by a phase lock loop (PLL)




                                                         12
www.OpenGNSS.org
                        II. Solving the problem of navigation




   a) How the problem is expressed

   b) Method of resolution using the mean squares

   c) Method of resolution using a Kalman filter




                                                   13
www.OpenGNSS.org
                   a) How the problem is expressed




                                     14
www.OpenGNSS.org
      b) Method of resolution using the mean squares (1/3)




                                            15
www.OpenGNSS.org
      b) Method of resolution using the mean squares (2/3)




                                            16
www.OpenGNSS.org
      b) Method of resolution using the mean squares (3/3)




                                            17
www.OpenGNSS.org

           c) Method of resolution using a Kalman filter (1/2)

    •Kalman filter : Less dependent on the configuration of satellites

    • Use the available observations + a parameters estimation model




                                                            18
www.OpenGNSS.org

         c) Method of resolution using a Kalman filter (2/2)




                                             19
www.OpenGNSS.org                             III. Errors correction




    a) Main causes of error

    b) Reducible errors by modelling or calculation

    c) Reducible errors by differentiation




                                                   20
www.OpenGNSS.org                   a) Main causes of error (1/2)




  • Errors reducing the
  precision :

  -Satellite’s errors (Doppler
  effect, ephemeris)

  -Environment’s errors
  (ionosphere, troposphere,
  multi-path)

  -Receiver’s errors
  (antenna, electronic circuits)




                                                 21
www.OpenGNSS.org                          a) Main causes of error (2/2)



     •Plan to use a corrective model for every source of error (depends on
     the receiver's model)

     • New expression of the pseudo-range :




                                                               22
www.OpenGNSS.org

           b) Reducible errors by modeling or calculation (1/3)

   • Ionosphere (50 to 100km altitude) : Environment ionized by solar radiations,
   the speed of the wave is modified




                                                                  23
www.OpenGNSS.org

          b) Reducible errors by modeling or calculation (2/3)

    • Other method more accurate by calculation, thanks to a dual frequencies
    receiver
    • Pseudo-range measurement with 2 frequencies (typicaly L1 and L2, both
    GPS frequencies)




                                                                24
www.OpenGNSS.org

          b) Reducible errors by modeling or calculation (3/ 3)


    • Tropospheric error (10 to 20km altitude) reducibles by modelisation

    •Variation of speed led by the angular curvature of the wave when
    crossing the troposphere because of the change of refractive
    index(depending on altitude, temperature, pression and humidity)

    •Amplitude of the delay depending on the angle according to which
    the receiver gets the satellite (small delay when satellite in the top,
    important delay when satellite on the horizon)

    •Use of a corrective model or a balloon which sounds temperature,
    humidity, and pressure (especially used in geodesy)




                                                              25
www.OpenGNSS.org

                       c) Reducible errors by differentiation (1/ 2)


    • Differential techniques => relative location

    • Need of a second receiver (static, in a shelter for instance)

    • Errors observed by both receivers identical: elimination by differentiation


    • Technics available :

    - Simple differentiation (1 satellite)

    - Double differentiation (2 satellites)

    - Triple differentiation (2 satellites but
    several mesures in time)

                                                      Simple differentiation


                                                                      26
www.OpenGNSS.org

                      c) Reducible errors by differentiation (2/ 2)

    • Example : simple differentiation




   • We find out the correction to be applied to the pseudo-range




                                                                    27
www.OpenGNSS.org           IV. Notions of integrity




    a) The DOP factor

    b) Integrity problem

    c) RAIM algorithms




                                   28
www.OpenGNSS.org                                     a) The DOP factor (1/3)




   •The DOP factor (Dilution Of Precision) : Represents the uncertainty on the
   position and allows to select the satellites which will supply to the receiver
   the best results




   •The error of position depends on the error of measure and on the
   geometry of the constellation of satellites




                                                                   29
www.OpenGNSS.org   a) The DOP factor (2/3)




                            30
www.OpenGNSS.org   a) The DOP factor (3/3)




                            31
www.OpenGNSS.org                                          b) Integrity problem



   • Procedure of exclusion, detects the abnormalities

   • 4 sources of errors: clock satellite, ephemeris, solar radiations, monitoring
   station

   • Integrity check up in 2 stages : detection of the breakdown, then exclusion
   from the failing measures




                                                                    32
www.OpenGNSS.org   c) RAIM algorithms (1/2)




                        • RAIM (Receiver
                        Autonomous Integrity
                        Monitoring) : Use the
                        redundancy of
                        information from
                        satellites to detect a
                        breakdown

                        • 3 possible algorithms :
                        Method consisting in
                        separation of the
                        solutions, the method of
                        residues, the
                        comparison method of
                        the pseudo-range



                                33
www.OpenGNSS.org   c) RAIM algorithms (2/2)




                             34
www.OpenGNSS.org                                                Conclusion




     •Complex system, very sensitive to the disturbances

     • Many parameters to be taken into account

     • Possibility of being coupled with the others system of
     navigation, according to the required use (SBAS/ABAS/GBAS)




                                                           35
www.OpenGNSS.org                                 Conclusion




     Thank you and let us meet on www.OpenGNSS.org
       to participate in the development OpenSource
                      of a GNSS receiver




                                            36

More Related Content

What's hot

Leos 2008 Th Aa2 20081113 V1.2
Leos 2008 Th Aa2 20081113 V1.2Leos 2008 Th Aa2 20081113 V1.2
Leos 2008 Th Aa2 20081113 V1.2
jrothim
 
OCEANSAT II
OCEANSAT IIOCEANSAT II
OCEANSAT II
Gagan Tanwar
 
Extra_Li_XF_2011_IGARSS_OilSpill.pptx
Extra_Li_XF_2011_IGARSS_OilSpill.pptxExtra_Li_XF_2011_IGARSS_OilSpill.pptx
Extra_Li_XF_2011_IGARSS_OilSpill.pptx
grssieee
 
High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...
High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...
High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...
Chromatography & Mass Spectrometry Solutions
 
Use of RSS and NMR for exploration in oil and gas industry but also for refur...
Use of RSS and NMR for exploration in oil and gas industry but also for refur...Use of RSS and NMR for exploration in oil and gas industry but also for refur...
Use of RSS and NMR for exploration in oil and gas industry but also for refur...
Fands-llc
 
TH2.L10.4: SMOS L1 ALGORITHMS
TH2.L10.4: SMOS L1 ALGORITHMSTH2.L10.4: SMOS L1 ALGORITHMS
TH2.L10.4: SMOS L1 ALGORITHMS
grssieee
 
Mace2010
Mace2010Mace2010
Mace2010
mnico61
 
IGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptx
IGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptxIGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptx
IGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptx
grssieee
 
Generating digital terrain models using lroc nac images
Generating digital terrain models using lroc nac imagesGenerating digital terrain models using lroc nac images
Generating digital terrain models using lroc nac images
Sérgio Sacani
 
General ideas About NMR technology
General ideas About NMR technologyGeneral ideas About NMR technology
General ideas About NMR technology
Fands-llc
 
11h00 carlos roberto 21 08 botafogo
11h00 carlos roberto 21 08 botafogo11h00 carlos roberto 21 08 botafogo
11h00 carlos roberto 21 08 botafogo
slides-mci
 
A Fully Automated System for Monitoring Pit Wall Displacements
 A Fully Automated System for Monitoring Pit Wall Displacements A Fully Automated System for Monitoring Pit Wall Displacements
A Fully Automated System for Monitoring Pit Wall Displacements
JOSE ESPEJO VASQUEZ
 
Sat geo 03(1)
Sat geo 03(1)Sat geo 03(1)
Sat geo 03(1)
lenisepti
 
In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...
In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...
In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...
Naivedya Mishra
 
10h10 carlos roberto 21 08 botafogo
10h10 carlos roberto 21 08 botafogo10h10 carlos roberto 21 08 botafogo
10h10 carlos roberto 21 08 botafogo
slides-mci
 
Thesis_powerpoint
Thesis_powerpointThesis_powerpoint
Thesis_powerpoint
Tim Costa
 
Poster Roseanne Clement
Poster Roseanne ClementPoster Roseanne Clement
Poster Roseanne Clement
Roseanne Clement
 
LWD Borehole Georadar (Proof of Concept)
LWD Borehole  Georadar (Proof of Concept)LWD Borehole  Georadar (Proof of Concept)
LWD Borehole Georadar (Proof of Concept)
Sergey Bondarenko
 
Investigation of repeated events at Jordan phosphate mine with waveform cross...
Investigation of repeated events at Jordan phosphate mine with waveform cross...Investigation of repeated events at Jordan phosphate mine with waveform cross...
Investigation of repeated events at Jordan phosphate mine with waveform cross...
Ivan Kitov
 

What's hot (19)

Leos 2008 Th Aa2 20081113 V1.2
Leos 2008 Th Aa2 20081113 V1.2Leos 2008 Th Aa2 20081113 V1.2
Leos 2008 Th Aa2 20081113 V1.2
 
OCEANSAT II
OCEANSAT IIOCEANSAT II
OCEANSAT II
 
Extra_Li_XF_2011_IGARSS_OilSpill.pptx
Extra_Li_XF_2011_IGARSS_OilSpill.pptxExtra_Li_XF_2011_IGARSS_OilSpill.pptx
Extra_Li_XF_2011_IGARSS_OilSpill.pptx
 
High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...
High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...
High Resolution Mass Spectrometry in Clinical Research: from Targeted Quantif...
 
Use of RSS and NMR for exploration in oil and gas industry but also for refur...
Use of RSS and NMR for exploration in oil and gas industry but also for refur...Use of RSS and NMR for exploration in oil and gas industry but also for refur...
Use of RSS and NMR for exploration in oil and gas industry but also for refur...
 
TH2.L10.4: SMOS L1 ALGORITHMS
TH2.L10.4: SMOS L1 ALGORITHMSTH2.L10.4: SMOS L1 ALGORITHMS
TH2.L10.4: SMOS L1 ALGORITHMS
 
Mace2010
Mace2010Mace2010
Mace2010
 
IGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptx
IGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptxIGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptx
IGARSS2011-Present_Status_of_GOCI-AHN_110722-03s.pptx
 
Generating digital terrain models using lroc nac images
Generating digital terrain models using lroc nac imagesGenerating digital terrain models using lroc nac images
Generating digital terrain models using lroc nac images
 
General ideas About NMR technology
General ideas About NMR technologyGeneral ideas About NMR technology
General ideas About NMR technology
 
11h00 carlos roberto 21 08 botafogo
11h00 carlos roberto 21 08 botafogo11h00 carlos roberto 21 08 botafogo
11h00 carlos roberto 21 08 botafogo
 
A Fully Automated System for Monitoring Pit Wall Displacements
 A Fully Automated System for Monitoring Pit Wall Displacements A Fully Automated System for Monitoring Pit Wall Displacements
A Fully Automated System for Monitoring Pit Wall Displacements
 
Sat geo 03(1)
Sat geo 03(1)Sat geo 03(1)
Sat geo 03(1)
 
In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...
In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...
In tech recent-advances_in_synthetic_aperture_radar_enhancement_and_informati...
 
10h10 carlos roberto 21 08 botafogo
10h10 carlos roberto 21 08 botafogo10h10 carlos roberto 21 08 botafogo
10h10 carlos roberto 21 08 botafogo
 
Thesis_powerpoint
Thesis_powerpointThesis_powerpoint
Thesis_powerpoint
 
Poster Roseanne Clement
Poster Roseanne ClementPoster Roseanne Clement
Poster Roseanne Clement
 
LWD Borehole Georadar (Proof of Concept)
LWD Borehole  Georadar (Proof of Concept)LWD Borehole  Georadar (Proof of Concept)
LWD Borehole Georadar (Proof of Concept)
 
Investigation of repeated events at Jordan phosphate mine with waveform cross...
Investigation of repeated events at Jordan phosphate mine with waveform cross...Investigation of repeated events at Jordan phosphate mine with waveform cross...
Investigation of repeated events at Jordan phosphate mine with waveform cross...
 

Viewers also liked

Real Time Corrections for GNSS Receivers
Real Time Corrections for GNSS ReceiversReal Time Corrections for GNSS Receivers
Real Time Corrections for GNSS Receivers
Hawaii Geographic Information Coordinating Council
 
Global Navigations Satellite System (GNSS) Indonesia
Global Navigations Satellite System (GNSS) IndonesiaGlobal Navigations Satellite System (GNSS) Indonesia
Global Navigations Satellite System (GNSS) Indonesia
Edi Supriyanto
 
47- les risques de désordres des construcions à ossature bois
 47- les risques de désordres des construcions à ossature bois 47- les risques de désordres des construcions à ossature bois
47- les risques de désordres des construcions à ossature boisrabahrabah
 
Towards Autonomous Driving on road: the E-GNSS contribution
Towards Autonomous Driving on road: the E-GNSS contributionTowards Autonomous Driving on road: the E-GNSS contribution
Towards Autonomous Driving on road: the E-GNSS contribution
The European GNSS Agency (GSA)
 
Leica GS16
Leica GS16Leica GS16
Leica GS16
leicageosystems
 
A Short History of Navigation Technologies
A Short History of Navigation TechnologiesA Short History of Navigation Technologies
A Short History of Navigation Technologies
Marco Lisi
 
Tachymetry survey POLITEKNIK MELAKA
Tachymetry survey POLITEKNIK MELAKATachymetry survey POLITEKNIK MELAKA
Tachymetry survey POLITEKNIK MELAKA
Riezat Zainal
 
Global navigation satellite system based positioning combined
Global navigation satellite system based positioning   combinedGlobal navigation satellite system based positioning   combined
Global navigation satellite system based positioning combined
Mehjabin Sultana
 
GNSS - Global Navigation Satellite System
GNSS - Global Navigation Satellite SystemGNSS - Global Navigation Satellite System
GNSS - Global Navigation Satellite System
Akshank Shah
 
Introduction-of-GNSS-2
Introduction-of-GNSS-2Introduction-of-GNSS-2
Introduction-of-GNSS-2
Kutubuddin ANSARI
 
Introduction to gps and gnss
Introduction to gps and gnssIntroduction to gps and gnss
Introduction to gps and gnss
Vivek Srivastava
 
GNSS
GNSSGNSS
غذاء وتغذية
غذاء وتغذيةغذاء وتغذية
غذاء وتغذية
AHMEDNESREN
 
Arithmetic
ArithmeticArithmetic
Arithmetic
Haider Shishmahal
 
هيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سورية
هيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سوريةهيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سورية
هيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سورية
saned charity
 
الدرس الأول للتفكير الإيجابي
الدرس الأول للتفكير الإيجابيالدرس الأول للتفكير الإيجابي
الدرس الأول للتفكير الإيجابيmaharty
 
Writiing issue essay gre
Writiing issue essay greWritiing issue essay gre
Writiing issue essay gre
Haider Shishmahal
 
Crtical Thinking Course
Crtical Thinking CourseCrtical Thinking Course
Crtical Thinking Coursemaharty
 
مهارتي دورة العصف الذهني 4
مهارتي دورة العصف الذهني 4مهارتي دورة العصف الذهني 4
مهارتي دورة العصف الذهني 4
maharty
 

Viewers also liked (20)

Real Time Corrections for GNSS Receivers
Real Time Corrections for GNSS ReceiversReal Time Corrections for GNSS Receivers
Real Time Corrections for GNSS Receivers
 
Global Navigations Satellite System (GNSS) Indonesia
Global Navigations Satellite System (GNSS) IndonesiaGlobal Navigations Satellite System (GNSS) Indonesia
Global Navigations Satellite System (GNSS) Indonesia
 
47- les risques de désordres des construcions à ossature bois
 47- les risques de désordres des construcions à ossature bois 47- les risques de désordres des construcions à ossature bois
47- les risques de désordres des construcions à ossature bois
 
Towards Autonomous Driving on road: the E-GNSS contribution
Towards Autonomous Driving on road: the E-GNSS contributionTowards Autonomous Driving on road: the E-GNSS contribution
Towards Autonomous Driving on road: the E-GNSS contribution
 
Leica GS16
Leica GS16Leica GS16
Leica GS16
 
A Short History of Navigation Technologies
A Short History of Navigation TechnologiesA Short History of Navigation Technologies
A Short History of Navigation Technologies
 
Tachymetry survey POLITEKNIK MELAKA
Tachymetry survey POLITEKNIK MELAKATachymetry survey POLITEKNIK MELAKA
Tachymetry survey POLITEKNIK MELAKA
 
Global navigation satellite system based positioning combined
Global navigation satellite system based positioning   combinedGlobal navigation satellite system based positioning   combined
Global navigation satellite system based positioning combined
 
GNSS - Global Navigation Satellite System
GNSS - Global Navigation Satellite SystemGNSS - Global Navigation Satellite System
GNSS - Global Navigation Satellite System
 
Introduction-of-GNSS-2
Introduction-of-GNSS-2Introduction-of-GNSS-2
Introduction-of-GNSS-2
 
Introduction to gps and gnss
Introduction to gps and gnssIntroduction to gps and gnss
Introduction to gps and gnss
 
GNSS
GNSSGNSS
GNSS
 
غذاء وتغذية
غذاء وتغذيةغذاء وتغذية
غذاء وتغذية
 
Arithmetic
ArithmeticArithmetic
Arithmetic
 
هيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سورية
هيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سوريةهيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سورية
هيئة ساند الوقفية مشروع تربية الداجاج البياض الوقفي على ارض سورية
 
الدرس الأول للتفكير الإيجابي
الدرس الأول للتفكير الإيجابيالدرس الأول للتفكير الإيجابي
الدرس الأول للتفكير الإيجابي
 
Writiing issue essay gre
Writiing issue essay greWritiing issue essay gre
Writiing issue essay gre
 
Crtical Thinking Course
Crtical Thinking CourseCrtical Thinking Course
Crtical Thinking Course
 
مهارتي دورة العصف الذهني 4
مهارتي دورة العصف الذهني 4مهارتي دورة العصف الذهني 4
مهارتي دورة العصف الذهني 4
 
Negpat
NegpatNegpat
Negpat
 

Similar to How does the GNSS receiver works ?

Combining remote sensing earth observations and in situ networks: detection o...
Combining remote sensing earth observations and in situ networks: detection o...Combining remote sensing earth observations and in situ networks: detection o...
Combining remote sensing earth observations and in situ networks: detection o...
Integrated Carbon Observation System (ICOS)
 
Morocco2022_LocationProblem_Bondar.pptx
Morocco2022_LocationProblem_Bondar.pptxMorocco2022_LocationProblem_Bondar.pptx
Morocco2022_LocationProblem_Bondar.pptx
ouchenibrahim1
 
The performance of portable mid-infrared spectroscopy for the prediction of s...
The performance of portable mid-infrared spectroscopy for the prediction of s...The performance of portable mid-infrared spectroscopy for the prediction of s...
The performance of portable mid-infrared spectroscopy for the prediction of s...
ExternalEvents
 
DGPS
DGPSDGPS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
jantjournal
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
jantjournal
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
jantjournal
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
jantjournal
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
jantjournal
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
jantjournal
 
Distributed Data Processing using Spark by Panos Labropoulos_and Sarod Yataw...
Distributed Data Processing using Spark by  Panos Labropoulos_and Sarod Yataw...Distributed Data Processing using Spark by  Panos Labropoulos_and Sarod Yataw...
Distributed Data Processing using Spark by Panos Labropoulos_and Sarod Yataw...
Spark Summit
 
Biases and Receivers (3)
Biases and Receivers (3)Biases and Receivers (3)
Biases and Receivers (3)
NopphawanTamkuan
 
Positioning techniques in 3 g networks (1)
Positioning techniques in 3 g networks (1)Positioning techniques in 3 g networks (1)
Positioning techniques in 3 g networks (1)
kike2005
 
isc2015
isc2015isc2015
isc2015
Yi Ling
 
The GPS/GNSS Signal (2)
The GPS/GNSS Signal (2)The GPS/GNSS Signal (2)
The GPS/GNSS Signal (2)
NopphawanTamkuan
 
Landmines Detection by Robots presentation
Landmines Detection by Robots  presentationLandmines Detection by Robots  presentation
Landmines Detection by Robots presentation
Ahmed Abdelaziz
 
9_Network.ppt
9_Network.ppt9_Network.ppt
9_Network.ppt
SushmaShivani
 
4. lecture 3 data capturing techniques - total station and gps
4. lecture 3   data capturing techniques - total station and gps4. lecture 3   data capturing techniques - total station and gps
4. lecture 3 data capturing techniques - total station and gps
FenTaHun6
 
4. lecture 3 data capturing techniques - total station and gps
4. lecture 3   data capturing techniques - total station and gps4. lecture 3   data capturing techniques - total station and gps
4. lecture 3 data capturing techniques - total station and gps
FenTaHun6
 
COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1
COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1
COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1
aishwaryaarrao3
 

Similar to How does the GNSS receiver works ? (20)

Combining remote sensing earth observations and in situ networks: detection o...
Combining remote sensing earth observations and in situ networks: detection o...Combining remote sensing earth observations and in situ networks: detection o...
Combining remote sensing earth observations and in situ networks: detection o...
 
Morocco2022_LocationProblem_Bondar.pptx
Morocco2022_LocationProblem_Bondar.pptxMorocco2022_LocationProblem_Bondar.pptx
Morocco2022_LocationProblem_Bondar.pptx
 
The performance of portable mid-infrared spectroscopy for the prediction of s...
The performance of portable mid-infrared spectroscopy for the prediction of s...The performance of portable mid-infrared spectroscopy for the prediction of s...
The performance of portable mid-infrared spectroscopy for the prediction of s...
 
DGPS
DGPSDGPS
DGPS
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
 
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONSDUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
DUAL BAND GNSS ANTENNA PHASE CENTER CHARACTERIZATION FOR AUTOMOTIVE APPLICATIONS
 
Distributed Data Processing using Spark by Panos Labropoulos_and Sarod Yataw...
Distributed Data Processing using Spark by  Panos Labropoulos_and Sarod Yataw...Distributed Data Processing using Spark by  Panos Labropoulos_and Sarod Yataw...
Distributed Data Processing using Spark by Panos Labropoulos_and Sarod Yataw...
 
Biases and Receivers (3)
Biases and Receivers (3)Biases and Receivers (3)
Biases and Receivers (3)
 
Positioning techniques in 3 g networks (1)
Positioning techniques in 3 g networks (1)Positioning techniques in 3 g networks (1)
Positioning techniques in 3 g networks (1)
 
isc2015
isc2015isc2015
isc2015
 
The GPS/GNSS Signal (2)
The GPS/GNSS Signal (2)The GPS/GNSS Signal (2)
The GPS/GNSS Signal (2)
 
Landmines Detection by Robots presentation
Landmines Detection by Robots  presentationLandmines Detection by Robots  presentation
Landmines Detection by Robots presentation
 
9_Network.ppt
9_Network.ppt9_Network.ppt
9_Network.ppt
 
4. lecture 3 data capturing techniques - total station and gps
4. lecture 3   data capturing techniques - total station and gps4. lecture 3   data capturing techniques - total station and gps
4. lecture 3 data capturing techniques - total station and gps
 
4. lecture 3 data capturing techniques - total station and gps
4. lecture 3   data capturing techniques - total station and gps4. lecture 3   data capturing techniques - total station and gps
4. lecture 3 data capturing techniques - total station and gps
 
COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1
COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1
COMPUTER NETWORKS CHAPTER 3 NETWORK LAYER NOTES CSE 3RD year sem 1
 

Recently uploaded

BIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptx
BIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptxBIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptx
BIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptx
RidwanHassanYusuf
 
HYPERTENSION - SLIDE SHARE PRESENTATION.
HYPERTENSION - SLIDE SHARE PRESENTATION.HYPERTENSION - SLIDE SHARE PRESENTATION.
HYPERTENSION - SLIDE SHARE PRESENTATION.
deepaannamalai16
 
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
National Information Standards Organization (NISO)
 
SWOT analysis in the project Keeping the Memory @live.pptx
SWOT analysis in the project Keeping the Memory @live.pptxSWOT analysis in the project Keeping the Memory @live.pptx
SWOT analysis in the project Keeping the Memory @live.pptx
zuzanka
 
Gender and Mental Health - Counselling and Family Therapy Applications and In...
Gender and Mental Health - Counselling and Family Therapy Applications and In...Gender and Mental Health - Counselling and Family Therapy Applications and In...
Gender and Mental Health - Counselling and Family Therapy Applications and In...
PsychoTech Services
 
spot a liar (Haiqa 146).pptx Technical writhing and presentation skills
spot a liar (Haiqa 146).pptx Technical writhing and presentation skillsspot a liar (Haiqa 146).pptx Technical writhing and presentation skills
spot a liar (Haiqa 146).pptx Technical writhing and presentation skills
haiqairshad
 
CIS 4200-02 Group 1 Final Project Report (1).pdf
CIS 4200-02 Group 1 Final Project Report (1).pdfCIS 4200-02 Group 1 Final Project Report (1).pdf
CIS 4200-02 Group 1 Final Project Report (1).pdf
blueshagoo1
 
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdfREASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
giancarloi8888
 
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem studentsRHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
Himanshu Rai
 
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...
EduSkills OECD
 
Bossa N’ Roll Records by Ismael Vazquez.
Bossa N’ Roll Records by Ismael Vazquez.Bossa N’ Roll Records by Ismael Vazquez.
Bossa N’ Roll Records by Ismael Vazquez.
IsmaelVazquez38
 
Chapter wise All Notes of First year Basic Civil Engineering.pptx
Chapter wise All Notes of First year Basic Civil Engineering.pptxChapter wise All Notes of First year Basic Civil Engineering.pptx
Chapter wise All Notes of First year Basic Civil Engineering.pptx
Denish Jangid
 
Bonku-Babus-Friend by Sathyajith Ray (9)
Bonku-Babus-Friend by Sathyajith Ray  (9)Bonku-Babus-Friend by Sathyajith Ray  (9)
Bonku-Babus-Friend by Sathyajith Ray (9)
nitinpv4ai
 
Data Structure using C by Dr. K Adisesha .ppsx
Data Structure using C by Dr. K Adisesha .ppsxData Structure using C by Dr. K Adisesha .ppsx
Data Structure using C by Dr. K Adisesha .ppsx
Prof. Dr. K. Adisesha
 
مصحف القراءات العشر أعد أحرف الخلاف سمير بسيوني.pdf
مصحف القراءات العشر   أعد أحرف الخلاف سمير بسيوني.pdfمصحف القراءات العشر   أعد أحرف الخلاف سمير بسيوني.pdf
مصحف القراءات العشر أعد أحرف الخلاف سمير بسيوني.pdf
سمير بسيوني
 
Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...
Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...
Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...
ImMuslim
 
Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...
Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...
Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...
imrankhan141184
 
How to deliver Powerpoint Presentations.pptx
How to deliver Powerpoint  Presentations.pptxHow to deliver Powerpoint  Presentations.pptx
How to deliver Powerpoint Presentations.pptx
HajraNaeem15
 
Leveraging Generative AI to Drive Nonprofit Innovation
Leveraging Generative AI to Drive Nonprofit InnovationLeveraging Generative AI to Drive Nonprofit Innovation
Leveraging Generative AI to Drive Nonprofit Innovation
TechSoup
 
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...
indexPub
 

Recently uploaded (20)

BIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptx
BIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptxBIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptx
BIOLOGY NATIONAL EXAMINATION COUNCIL (NECO) 2024 PRACTICAL MANUAL.pptx
 
HYPERTENSION - SLIDE SHARE PRESENTATION.
HYPERTENSION - SLIDE SHARE PRESENTATION.HYPERTENSION - SLIDE SHARE PRESENTATION.
HYPERTENSION - SLIDE SHARE PRESENTATION.
 
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
Jemison, MacLaughlin, and Majumder "Broadening Pathways for Editors and Authors"
 
SWOT analysis in the project Keeping the Memory @live.pptx
SWOT analysis in the project Keeping the Memory @live.pptxSWOT analysis in the project Keeping the Memory @live.pptx
SWOT analysis in the project Keeping the Memory @live.pptx
 
Gender and Mental Health - Counselling and Family Therapy Applications and In...
Gender and Mental Health - Counselling and Family Therapy Applications and In...Gender and Mental Health - Counselling and Family Therapy Applications and In...
Gender and Mental Health - Counselling and Family Therapy Applications and In...
 
spot a liar (Haiqa 146).pptx Technical writhing and presentation skills
spot a liar (Haiqa 146).pptx Technical writhing and presentation skillsspot a liar (Haiqa 146).pptx Technical writhing and presentation skills
spot a liar (Haiqa 146).pptx Technical writhing and presentation skills
 
CIS 4200-02 Group 1 Final Project Report (1).pdf
CIS 4200-02 Group 1 Final Project Report (1).pdfCIS 4200-02 Group 1 Final Project Report (1).pdf
CIS 4200-02 Group 1 Final Project Report (1).pdf
 
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdfREASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
REASIGNACION 2024 UGEL CHUPACA 2024 UGEL CHUPACA.pdf
 
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem studentsRHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
RHEOLOGY Physical pharmaceutics-II notes for B.pharm 4th sem students
 
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...
Andreas Schleicher presents PISA 2022 Volume III - Creative Thinking - 18 Jun...
 
Bossa N’ Roll Records by Ismael Vazquez.
Bossa N’ Roll Records by Ismael Vazquez.Bossa N’ Roll Records by Ismael Vazquez.
Bossa N’ Roll Records by Ismael Vazquez.
 
Chapter wise All Notes of First year Basic Civil Engineering.pptx
Chapter wise All Notes of First year Basic Civil Engineering.pptxChapter wise All Notes of First year Basic Civil Engineering.pptx
Chapter wise All Notes of First year Basic Civil Engineering.pptx
 
Bonku-Babus-Friend by Sathyajith Ray (9)
Bonku-Babus-Friend by Sathyajith Ray  (9)Bonku-Babus-Friend by Sathyajith Ray  (9)
Bonku-Babus-Friend by Sathyajith Ray (9)
 
Data Structure using C by Dr. K Adisesha .ppsx
Data Structure using C by Dr. K Adisesha .ppsxData Structure using C by Dr. K Adisesha .ppsx
Data Structure using C by Dr. K Adisesha .ppsx
 
مصحف القراءات العشر أعد أحرف الخلاف سمير بسيوني.pdf
مصحف القراءات العشر   أعد أحرف الخلاف سمير بسيوني.pdfمصحف القراءات العشر   أعد أحرف الخلاف سمير بسيوني.pdf
مصحف القراءات العشر أعد أحرف الخلاف سمير بسيوني.pdf
 
Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...
Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...
Geography as a Discipline Chapter 1 __ Class 11 Geography NCERT _ Class Notes...
 
Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...
Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...
Traditional Musical Instruments of Arunachal Pradesh and Uttar Pradesh - RAYH...
 
How to deliver Powerpoint Presentations.pptx
How to deliver Powerpoint  Presentations.pptxHow to deliver Powerpoint  Presentations.pptx
How to deliver Powerpoint Presentations.pptx
 
Leveraging Generative AI to Drive Nonprofit Innovation
Leveraging Generative AI to Drive Nonprofit InnovationLeveraging Generative AI to Drive Nonprofit Innovation
Leveraging Generative AI to Drive Nonprofit Innovation
 
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...
THE SACRIFICE HOW PRO-PALESTINE PROTESTS STUDENTS ARE SACRIFICING TO CHANGE T...
 

How does the GNSS receiver works ?

  • 1. www.OpenGNSS.org OpenGNSS www.OpenGNSS.org proposes you this course free of charge OpenGNSS is a project cofinanced by HELILEO (www. HELILEO.com), TECNALIA (www. TECNALIA.es), the Regional Council of Aquitaine and the Basque government
  • 2. www.OpenGNSS.org How does a GNSS receiver work ?
  • 3. www.OpenGNSS.org Summary I. General Principle II. Solving the problem of navigation III. Error correction IV. Notions of integrity 3
  • 4. www.OpenGNSS.org Introduction (1/2) • GNSS Receivers : GPS, GLONASS, Galileo • Application domains : guidance, data synchronization, geodesy • Position computing thanks to satellite signal reception time Errors to consider: • Clock bias • Environment (troposphere, ionosphere, multipath) • Dynamic (movement / satellite receiver: Doppler effect) • Noise 4
  • 5. www.OpenGNSS.org Introduction (2/2) Functioning scheme 5
  • 6. www.OpenGNSS.org I. General principle a) Pseudo-range computation b) Process based upon code measurement c) Process based upon phase measurement 6
  • 7. www.OpenGNSS.org a) Pseudo-range computation (1/2) Receipt channel scheme Receipt channel: Distance - Correlator -Tracking loop Received signal - Data decoding Velocity - Distances computation - Velocity computation Navigation data Satellite code 7
  • 8. www.OpenGNSS.org a) Pseudo-range computation (2/2) Where c is the speed of the wave in the space when the wave is received when the wave is emitted You get then the "pseudo-range" + the clock offset errors 8
  • 9. www.OpenGNSS.org b) Process based upon code measurement (1/3) • Each satellite uses a pseudo random noise code (PRN code) associated to its signal • Periodical signal which value is 0 or 1 • Same signal generated by the receiver Received signal Correlator output Local signal • Use of a correlator • Correlation peak= dt (clock bias) 9
  • 10. www.OpenGNSS.org b) Process based upon code measurement (2/3) 10
  • 11. www.OpenGNSS.org b) Process based upon code measurement (3/3) Code pursuit • Use of correlators (Early, on time, late) • Differentiation=feedback control loop • Ambiguity on measurement, simple but not very precise and surrounded by noise • Phase measurement=> precision more accurate 11
  • 12. www.OpenGNSS.org c) Process based upon phase measurement •Measurement of a difference of phase between local signal and emitted signal (ambiguity increased) •Possibility to combine measurement of code and phase in order to combine precision / non ambiguity •Difference of phase obtained by a phase lock loop (PLL) 12
  • 13. www.OpenGNSS.org II. Solving the problem of navigation a) How the problem is expressed b) Method of resolution using the mean squares c) Method of resolution using a Kalman filter 13
  • 14. www.OpenGNSS.org a) How the problem is expressed 14
  • 15. www.OpenGNSS.org b) Method of resolution using the mean squares (1/3) 15
  • 16. www.OpenGNSS.org b) Method of resolution using the mean squares (2/3) 16
  • 17. www.OpenGNSS.org b) Method of resolution using the mean squares (3/3) 17
  • 18. www.OpenGNSS.org c) Method of resolution using a Kalman filter (1/2) •Kalman filter : Less dependent on the configuration of satellites • Use the available observations + a parameters estimation model 18
  • 19. www.OpenGNSS.org c) Method of resolution using a Kalman filter (2/2) 19
  • 20. www.OpenGNSS.org III. Errors correction a) Main causes of error b) Reducible errors by modelling or calculation c) Reducible errors by differentiation 20
  • 21. www.OpenGNSS.org a) Main causes of error (1/2) • Errors reducing the precision : -Satellite’s errors (Doppler effect, ephemeris) -Environment’s errors (ionosphere, troposphere, multi-path) -Receiver’s errors (antenna, electronic circuits) 21
  • 22. www.OpenGNSS.org a) Main causes of error (2/2) •Plan to use a corrective model for every source of error (depends on the receiver's model) • New expression of the pseudo-range : 22
  • 23. www.OpenGNSS.org b) Reducible errors by modeling or calculation (1/3) • Ionosphere (50 to 100km altitude) : Environment ionized by solar radiations, the speed of the wave is modified 23
  • 24. www.OpenGNSS.org b) Reducible errors by modeling or calculation (2/3) • Other method more accurate by calculation, thanks to a dual frequencies receiver • Pseudo-range measurement with 2 frequencies (typicaly L1 and L2, both GPS frequencies) 24
  • 25. www.OpenGNSS.org b) Reducible errors by modeling or calculation (3/ 3) • Tropospheric error (10 to 20km altitude) reducibles by modelisation •Variation of speed led by the angular curvature of the wave when crossing the troposphere because of the change of refractive index(depending on altitude, temperature, pression and humidity) •Amplitude of the delay depending on the angle according to which the receiver gets the satellite (small delay when satellite in the top, important delay when satellite on the horizon) •Use of a corrective model or a balloon which sounds temperature, humidity, and pressure (especially used in geodesy) 25
  • 26. www.OpenGNSS.org c) Reducible errors by differentiation (1/ 2) • Differential techniques => relative location • Need of a second receiver (static, in a shelter for instance) • Errors observed by both receivers identical: elimination by differentiation • Technics available : - Simple differentiation (1 satellite) - Double differentiation (2 satellites) - Triple differentiation (2 satellites but several mesures in time) Simple differentiation 26
  • 27. www.OpenGNSS.org c) Reducible errors by differentiation (2/ 2) • Example : simple differentiation • We find out the correction to be applied to the pseudo-range 27
  • 28. www.OpenGNSS.org IV. Notions of integrity a) The DOP factor b) Integrity problem c) RAIM algorithms 28
  • 29. www.OpenGNSS.org a) The DOP factor (1/3) •The DOP factor (Dilution Of Precision) : Represents the uncertainty on the position and allows to select the satellites which will supply to the receiver the best results •The error of position depends on the error of measure and on the geometry of the constellation of satellites 29
  • 30. www.OpenGNSS.org a) The DOP factor (2/3) 30
  • 31. www.OpenGNSS.org a) The DOP factor (3/3) 31
  • 32. www.OpenGNSS.org b) Integrity problem • Procedure of exclusion, detects the abnormalities • 4 sources of errors: clock satellite, ephemeris, solar radiations, monitoring station • Integrity check up in 2 stages : detection of the breakdown, then exclusion from the failing measures 32
  • 33. www.OpenGNSS.org c) RAIM algorithms (1/2) • RAIM (Receiver Autonomous Integrity Monitoring) : Use the redundancy of information from satellites to detect a breakdown • 3 possible algorithms : Method consisting in separation of the solutions, the method of residues, the comparison method of the pseudo-range 33
  • 34. www.OpenGNSS.org c) RAIM algorithms (2/2) 34
  • 35. www.OpenGNSS.org Conclusion •Complex system, very sensitive to the disturbances • Many parameters to be taken into account • Possibility of being coupled with the others system of navigation, according to the required use (SBAS/ABAS/GBAS) 35
  • 36. www.OpenGNSS.org Conclusion Thank you and let us meet on www.OpenGNSS.org to participate in the development OpenSource of a GNSS receiver 36