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1. amp gA GE U P C Tutorial associated to the GNSS Data Processing book 5 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia Example of computation with gLAB Mode 1 Single frequency C1 code with broadcast orbits amp clocks Code positioning broadcast orbits Single frequency C1 code gLAB Version 2 0 0 gLAB esa gAGEUPC Preferences About Positioning Analysis Modelling Options Satellite clock offset correction K K Consider satellite movement during signal flight time Consider Earth rotation during signal flight time Satellite mass center to antenna phase center correctio Receiver antenna phase center correction From SPP template disable e Tropospheric e lonospheric Receiver antenna reference point correction Relativistic clock correction orbit excentricity lonospheric correction Tropospheric correction RINEX Nav File Oo DOS O UO C IS P1 P2 correction P1 Cl correction Flexible Ly Wind up correction Carrier phase only ww is Solid tides correction Relativistic path range correction Save Config SPP Template PPP Template RungLAB Show Output 9 gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia htt
2. remove ionospheric error Save Config SPP Templat PPP Template RungLAB TS a and P1 P2 DCBs Q aes GE U P M Tutorial associated to the GNSS Data Processing book 60 ich gro up of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Te chnical Un Mito of Catalo Exercise 2 PPP Model components analysis meters Code and carrier Measurements Comparison of measurement noise of LC and PC GUSN PRN14 52 50 f 48 F p W PT 46 aA LE AD LEO OK 40 Code is unambiguous but noisy 38 Zoom of carrier noise prefit LC 36 F prefit PC 34 10000 15000 20000 25000 seconds of day 2009 328 30000 35000 Code measurements are unambiguous but noisy meter level measurement noise Carrier measurements are precise but ambiguous meaning that they have few millimetres of noise but also have unknown biases that could reach thousands of km Carrier phase biases are estimated in the navigation filter along with the other parameters coordinates clock offsets etc If these biases were fixed measurements accurate to the level of few millimetres would be available for positioning However some time is needed to decorrelate such biases from Note Figure shows the noise of code and carrier prefit the other parameters in the filter and the residuals which are the input data for navigation equations estimated
3. gAGE UPC aC ku Tutorial associated to the GNSS Data Processing book 114 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia HW3 Code measurements noise assessment C1 P1 P2 and PC P1 code measurement noise and multipath Cl code measurement noise and mapee Je yg gis eed Comments ME ind dios AS Large noise patterns appear at the end of each data arc This is due to interference cross talk with other components The figure at bottom shows the multipath map for the GRACE A e P2 code is noisier than P1 or C1 m e PC code combination is the noisiest one meters meters D0 fo on nccccrcccccccccnccccccccssscay a Psccongeccseconge 45000 50000 55000 50000 65000 45000 50000 55000 60000 65000 as expected time 5 time s P P2 code isinaka noise and multipath Ionosphere free combination measurement noise PC LC 2 M 4 s PRN21 d av rg za el T E S A Ds C1 multipath map of sat GRACE A A GPS satellite a gt 0 track is shown in y blue This figure is from P Ramos Bosch PhD dissertation gAGE UPC 2008 E 45000 50000 55000 xu MESE 10 45000 50000 ANT 60000 65000 time 5 time s amp gA G E U P C Tutorial associated to the GNSS Data Processing book 115 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Research group of Astronomy amp Geomatic
4. UP error off Zoom Relativistic correction on satellite clock due to orbit eccentricity This is an additional correction to apply at the receiver level The satellite clock oscillator has been quod gLAB1 out 00 dij PO o modified to compensate for E 0 15006 50000 30006 40000 Sog 60000 70000 80000 90000 10000 20000 30000 40000 spy 60000 70000 80000 90000 the main effect 40us day ime s S A error m amp gA GE U P C Tutorial associated to the GNSS Data Processing book 47 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Exercise 1 SPP Model components analysis Relativistic clock correction 1 A constant component depending only on nominal value of satellite s orbit major semi axis It is corrected modifying satellite s clock oscillator frequency z 4 464 10 being f 10 23 MHz we have Af 4 464 10 f 4 57 10 Hz So satellite should use f5210 22999999543 MHz 2 A periodic component due to orbit eccentricity must be corrected by user receiver rel 22 td esin E ed meters C C Being u G Mg 23 986005 107 m s the gravitational constant c 2299792458 m s light speed in vacuum is orbits major semi axis is its eccentricity E is satellites eccentric anomaly and r and v are satellite s geocentric position and speed in an inertial system gAGE UPC
5. After such ambiguities reinitialization the filter needs some time to converge 107000 BR Carrier phase ambiguities converge e ES ON A m oe I c en a NE d quickly thanks to the rapid variation of 1 X 7 ES 1 acere qi niae So Pen geometry due to the LEO movement along its orbital path Plot HW5 c 68000 69000 70000 71000 Plot HW5 d 50000 55000 60000 107000 72000 73000 74000 A860 45000 65000 70000 amp gA G E U P C Tutorial associated to the GNSS Data Processing book 120 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia HW6 Single freq L1 C1 carrier and code with precise orbits amp clocks using Klobuchar ionospheric corrections Code and Carrier precise orbits amp clocks Single frequency L1 C1 Klobuchar ionosphere gLAB Version 2 0 0 gLAB 6 gAGEUPG http www gage es Configure gLAB as in Mode 5 and complete the following steps Input Upload the e brdc0800 07n file to IONO e brdc0800 07n file to DCBs fesa Preferences About Positioning Analysis Input Files A priori receiver position Examine Calculate Use RINEX Position Specify Use SINEX File RINEX Observation File home gLAB graa0800 070
6. OVERVIEW Y Introduction v The gLAB tool suite Y Examples of GNSS Positioning using gLAB Y Laboratory session organization LABORATORY Session Y Starting up your laptop Y Basic Introductory laboratory exercises Ex1 Ex2 Medium Laboratory Work Project LWP Kinematic positioning of a LEO satellite Advanced Homework amp gA GE U P C Tutorial associated to the GNSS Data Processing book 7 1 Research group of Astronomy amp Geomatics J irana J M Juan Zornoza M Her ajares Technical University of Catalonia t Sanz Subi n ndez P LWP Kinematic positioning of a LEO satellite A A kinematic positioning of GRACE A satellite is proposed in this exercise as a driven example to study and discuss the different navigation modes and modelling options for code or code amp carrier positioning of a rover receiver GRACE SATELLITES A amp B GPS Omnidirectional Antenna Satellite Attitude Nominal altitude 460 km and Orbit Control System Orbital periode 1 5 h aprox Mass 432 kg Launch date May 17 2002 Space Agency NASA GFZ Designed life time 5 years Receiver pseudorange noise 40 cm Receiver carrier phase noise 8 mm Receiver GRAPHIC noise 12 cm 9 Antenna phase center 0 0 0 0 0 414 m GPS Backup Omnidirectional Antenna AOCS GPS 45 FOV Antenna Radio Occultation Data More details at http op gfz potsdam de grace index GRACE html B g
7. Show ANTEX File home gLAB igs05_1402 atx Ex Examine Orbit and Clock Source X ml Broadcast Precise 1 file Precise 2 files Y m SP3 File home gLAB cod14193 sp3 Examine ds Preferences Z ng mimm Anal CLK File hpome gLAB cod14193 clk Examine e 2 Mod e 1 Set lonosphere Source if activated SINEX Flle Vi Show Modelling Options Precise P Pt p2 P fy v Satellite clock offset correction ETE CO r r ry l 1 RINEX Navigation File home gLAB brdc0800 07n Examine V Consider satellite movement during signal flight time M Consider Earth rotation during signal flight time Clock in e O N O CO rr Auxiliary Files Satellite mass center to antenna phase center correction P1 C1 Correction P1 P2 Correction Q Receiver antenna phase center correction Show Vi Show c C Receiver antenna reference point correction DCB Source Broadcast specify iv lonospheric correction Klobuchar RINEX Nav File home gLAB brdc0800 07n Examine C Tropospheric correction I P1 P2 correction RINEX Nav File Save Config SPP Template PPP Template M Wind up correction Carrier phase only C Solid tides correction MV Relativistic path range correction Save Config SPP Template PPP Template Run gLAB amp gA G E U P C Tutorial associated to the GNSS Data Processing book 2 1 Research group of
8. 45000 50000 55000 60000 65000 time s F 9 gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Upload file dif out in Plot 1 Plot 2 amp Plot 3 Ooo s8s Tutorial associated to the GNSS Data Processing book 7 8 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Mode 1 Single frequency C1 code with broadcast orbits amp clocks GRACE A Broadcast positioning C1 Along Track error GRACE A Broadcast positioning C1 Radial error Questions EA oe DU TOME etin baia aid iia Is it reasonable to disable the tropospheric and ionospheric corrections T z 10 i i 1 UN oe Se ee e ede Like GPS satellites LEOs ee een are also affected by un relativistic effects Is it necessary to introduce an additional model term to account for this effect GRACE A Broadcast positioning C1 Cross Track error elisha POSU Me 3 Radial Along Track Cross Track What could be the reason for the large error peaks seen in the plots meters 55000 BOO00 565000 time 5 B gA GE U P C Tutorial associated to the GNSS Data Processing book 9 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Mode 1 Single frequency C1 code with broadcast orbits amp
9. Modelling Options Precise Products Data Interpolation i 7 Satellite clock offse amp correction SINEX File Orbit Interpolation Degree 10 J M Consider satellite moW amp ment during signal flight time v Consider Earth rotation Wiring signal flight time Clock Interpolation Degree 0 phase center correction M Satellite mass center to alenna g P1 P2 Correction v Show Note DCB Source Broadcast specify A l g RINEX Nav File home gLAB brdc0800 07n Examine TGDs i e P1 P2 v Wind up correction Carrier phase only DCBs are need ed T Salid tides correction SPP Template PPP Template Run gLAB Show Output Relativistic path range correction for single frequency ay Save Config SPP Template PPP Template Run gLAB Show Qutput positioning B gA GE U C Tutorial associated to the GNSS Data Processing book 95 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 5 Single freq L1 C1 carrier and code with precise orbits amp clocks Example of computation with gLAB Code and Carrier precise orbits amp clocks Single frequency L1 C1 Complete the steps 3 Filter e Single Frequency measurements Single frequency oet L1P L1 carrier C1P P1 code 4 Run gLAB 5 n console mode e Convert the gLAB out to orb sp3 format f
10. HW1 Assess the ionospheric delay on the GRACE A satellite measurements Compare with the Klobuchar model corrections HW2 Plot in the same graph the True 3D error the Formal 3D error I e the 3D sigma and the number of satellites used Analyze the evolution of the error HW3 Assess the measurement noise on the C1 P1 P2 measurements and the PC code combination HW4 Assess the broadcast orbits and clocks accuracy using the precise products as the truth HW5 Analyze the carrier phase biases convergence in this kinematic PPP positioning aes G E U P C Tutorial associated to the GNSS Data Processing book 100 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares oe up o of Astro nomy amp Geomatics ie chnical Un rsity of Catalonia Proposed Homework exercises A HW6 Apply the Klobuchar model to the L1 P1 positioning with precise orbits and clocks and discuss the results A HW7 Generate a file with the satellite track in a Earth Fixed Earth Centered reference frame to be viewed with Google earth amp gAGE UI C Tutori Research group of Astronomy amp Geomatics J Technical University of Catalonia t Sanz Subira al associated to the GNSS Data Processing book 101 irana J M Juan Zornoza M Hernandez Pajares Backup slides Homework help and answers amp gA G E U P C Tutorial associated to the GNSS Data Processing book 102 J Sanz Subirana J M Juan Zornoz
11. Exercise 1 SPP Model components analysis Total Group Delay correction TGD P2 P1 Differential Code Bias DCB e Instrumental delays are associated to antennas cables as well as different filters used in receivers and satellites They affect both code and carrier measurements e Code instrumental delays depend on the frequency and the codes used and are different for the receiver and the satellites e Dual frequency users cancel such delays when using the ionosphere free combination of codes and carrier phases e For single frequency users the satellite instrumental delays 1 GDs are broadcast in the navigation message The receiver instrumental delay on the other hand is assimilated into the receiver clock estimation That is being common for all satellites it is assumed as zero and it is included in the receiver clock offset estimation J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares 90 gA GE U P M ac ku D Tutorial associated to the GNSS Data Processing book dics idis bii bii eomatics s chnical University of Catalon Exercise 1 SPP Model components analysis NEU positioning error SPP Full model Vertical positioning error SPP Horizontal error SPP 150 1000000 North error East error UP error 100 500000 L ee beaches eee Piae T 50 E E 5 5 0 0 3 f J x w 2 t o z 50 500000 L bee bee mE bee erem 100
12. Q Po Other options Coordinates les m les m C Backward filtefig Receiver Clock 9e10 m2 9e10 m are come aia rr anans Soran ss amp Note The igs pre1400 atx file contains the APC used by IGS before GPS week 1400 Save Config SPP Template PPP Template Run gLAB gAGE UPC Tutorial associated to the GNSS Data Processing book 58 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Exercise 2 PPP Model components analysis Kinematic PPP solution using files rano1230 00o igs10602 sp3 igs prei1400 atx igs00P1060 snx Cosa glLAB O GAGEUPC http www gage es CE North error Preferences About _ East Error Positioning Analysis Pe eee UP erar l gLAB out Messages V Print INFO Messages NEU positioning error Kinem PPP Output Des Output File Examine ee ee ee ee ee ee a ee ee ee a ee Set output file gLAB out for the FULL model as in previous case i Print CS Cycle Slip Messag I lt Print INPUT Messages error m L Print MEAS Message K Print MODEL Messages Print EPOCHSAT Messages EI DUE a S Print PREFIT Messages K Print POSTFIT Messages Print FILTER Messages amp K Print OUTPUT Messages
13. Research group of Astronomy amp Geomatics Technical University of Catalonia aC ku Tutorial associated to the GNSS Data Processing book 48 D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Exercise 1 SPP Model components analysis NEU positioning error SPP Full model Vertical positioning error SPP Horizontal positioning error SPP 150 North error East error 5 UP error 100 Fee estrone MEME VUOLE dac LOC MESE error m o Up error m FLOS EET 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s NEU error SPP No TGD corr 2nd May 2000 East error m off Zoom P2 P1 Differential Code Bias Total Group Delay TGD correction M4 These instrumental delays P cocco eee ee M ee can affect up to few meters ME NMENE ME NN MN being the satellite TGDs broadcast in the navigation North error East error UP error IUB oor CNN VM QN Ree Peg ao ghee eae S Az error m o meters NJ o ri n gLAB1 out 7 pee message for single frequency 1509 10000 20000 30000 70000 s0000 50000 70000 30000 90000 48000 20000 30000 40000 30000 60000 70000 30000 90000 users amp e gA GE U P C Tutorial associated to the GNSS Data Processing book 49 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia
14. Save Config SPP Template PPP Template RungLAB 5 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s B gA GE U P C Tutorial associated to the GNSS Data Processing book 59 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Exercise 2 PPP Model components analysis gLAB Version 2 0 0 Hesa gLAB EA 6 gAGEUPC Additional model L www components are used Preferences Preferences About pee 0 nn now in the FULL model to assure a centimeter Modelling Options Precise Products Data Interpolation level Ii od el N Satellite clock offset correction i o 7 Orbit Interpolation Degree 10 Consider satellite movement during signal flight time ae dc aye soe 5 Vm leg Clock Interpolation Degree o i T EEADERS P bit d clock Satellite mass center to antenna phase center correction Receiver Antenna Phase Center Correction recise Or S an C OC S Receiver antenna phase center correction Specify e Read from ANTEX nN ste ad of D ro ad cast O a es Receiver antenna reference point correction Dual frequency Code and 3 arrier data instead of only jn reed roris e single frequency code P1 Cl correction Flexible Wind up correction Carrier phase only e lo n o free CO Ti bI N ati O N of Solid tides correction Relativistic path range correction Cod es and carriers to
15. prefit residuals Postfit residuals Orbit and Clock comparison Global Gr phic Parameters Title Y label error m Clear X label time s U positioning error Y min Y max atic Limits X min X max Indivit al Plot s Configuration error imi O Plot Nr 4 Source Examine Dotted Line v e P mM MS 5 l M Condition OUTPUT iv Blue m X Column SEC via v 18 Label North error A00 i 9 99e SS Se BLUE See DE REDI LR 10000 20000 30000 40000 50000 60000 70000 p000 20000 time qs gA GE U P C Tutorial associated to the GNSS Data Processing book 38 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia Vertical Position Error plot from gLAB out gLAB1 out gLAB Version 2 0 0 gL AB n gLAB Saar 5 0 0 Vertical positioning error SPP Full model No lono corr iv JM Preferences Cesa Cesa E ecu i Prefefence Positioning Analysis d MK Templates Positioning Analysis Abou 8000 20000 30000 40000 50000 60000 70000 80000 90000 Time s SR NC Templates NEU positioning error Horizontal positioning error Zenith Tropospher E x r x
16. PRN16 f I1 txt c 1 21 x2 y3 so cl g 1 PRN21 xn 43000 xx 67000 yn 10 yx 10 aC ku Tutorial associated to the GNSS Data Processing book 106 D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia HW1 Assessing the ionospheric delay on the GRACE A satellite STEC meters of L1 delay lonospheric delay 10 LT orn re oli 5 Beek ate ke epee oe See ees uM 10 45000 50000 55000 60000 65000 time s Plot HW1 b STEC variations of few meters are typically experienced but in some cases they reach up to 8 meters of L1 delay gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia lonospheric delay e PRN16 Klob shifted e PRN21 Klob shifted e PRN16 1 2 C1 L1 e PRN21 1 2 C1 L1 STEC meters of L1 delay Large discrepancies with Klobuchar appear 45000 50000 55000 60000 65000 time s Plot HW1 c L1 C1 iono estimate is less noisier than the P2 P1 On the other hand large discrepancies appear when comparing with Klobuchar corrections Tutorial associated to the GNSS Data Processing book 107 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares HW1 Assessing the ionospheric delay on the GRACE A satellite A Plot HW1 c generation working with the GUI and in console mode 1 Using the gLAB c
17. 1 antennas s 20 e 97 1 9 0 7 30 0000000 0 125 9 52317 6 22127685 105 14268715 899 8 11118481 28445 22127685 4014 22672158 746 11510817 892 7 8969469 30045 22672158 5184 lt 25 22594902 367 12949753 825 7 10090708 53945 22594903 7394 Navigation 9 22731128 796 11621184 951 7 9055464 16945 22731130 0004 lt 5 3 7 data a processing 24610920 702 924108 174 6 720085 67045 24610920 0404 lt 2 20718775 074 18605935 474 9 14498133 97346 20718775 6074 lt 1 20842713 610 19083282 892 9 14870090 55546 20842713 4814 6 filter pesition amp ale estimation Emission 300m e ij n Pseudorange e Hot s MEHR correction e e Jel e Man Machine Lol e Interface Satellite clock offset lt 300Km Relativistic correction lt 13 m M Feeudorange Sat instrumental delays TGD m j P1 P2 C A e i E o p ox Aiding ar integrated receiver i Geometric distance pO 20 000Km po EPTSR64 0 eec 0 0 00000000 090 SENSORS lonospheric delay 2 50 m Tropospheric delay 2 10 m eceiver clock offset lt 300Km E Receiver instrumental delays m gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia gt gAGE Learning Material Windows Internet Explorer Sele GNSS Format Descriptions Go faa mpm A GNSS data files follow a well defined set of standar
18. Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia HW6 Single freq L1 C1 carrier and code with precise orbits amp clocks using Klobuchar ionospheric corrections Code and Carrier precise orbits amp clocks Single frequency L1 C1 Klobuchar ionosphere Complete the steps Single frequency g j 3 Filter e Single Frequency measurements L1P L1 carrier C1P P1 code OLip 0 01 meters 4 In console mode Convert the glab out Convert the output gLAB out file to sp3 format to orb Sp3 form aT file Execute in Console 4 Compute differences 2 Compare the computed coordinates orb sp3 with reference GRAA 07 80 sp3 With reference file j GRAA 07 080 sp3 T B Make plots as before orb sp3 amp gA G E U P C Tutorial associated to the GNSS Data Processing book 122 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia HW6 Single freq L1 C1 carrier and code with precise orbits amp clocks using Klobuchar ionospheric corrections suitable men Klob Radial error Co m m e nts Aclear degradation is seen when GRACE A Broadcast positioning P1L1 Klob Along Track error 8 ground receivers not for LEOs e Next plot compares the L1 delay computed from Klobuchar with the STEC exp
19. accuracy over 24h data is achieved LI LI Loue im ee ee ee Ds cmm n re rp or Im orm 1 D D LI LI Li LI 1 1 1 1 1 1 1 1 D D LI LI LI LI LI 1 1 1 1 D Global Graphic Parameters x r b r Title NEU positioning error Xa time 5 Yia error m Clear y Automatic Limits X min X max Y min Ymax 0 a z Q nee Pi ati 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 sepa eee ae time s Blue X Column SEC amp gA GE U P C Tutorial associated to the GNSS Data Processing book 21 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Example 3 Kinematic Precise Point Positioning From default configuration of PPP Template e Select kinematics in the Filter panel Run gLAB and plot results NEU positioning error Kinematic PPP North error Cesa g LABS mpi 2 East error 8 E E E Preferences i About Positioning alysis nd UP error Measuremen ts Troposher POR ee spher Phase Ambiguities 1 Pseudorange Pseudorange Smoothing epochs Pseudorange Carrier phase Available Frequencies Single Frequency Measuremen t configuration and noise Dual Frequency ms PC Fixed StdDev m 1 Elevation StdDev m E LC v Fixed StdDev m 0 01 Elevati
20. amb out containing the estimates of ambiguities for each epoch Take the last estimated value of the ambiguities for each epoch This can be done by executing grep POSTFIT gLAB out gawk i 6 4 a i 13 END for i in a print i a i sort n gt amb out Plot the results Plot the ionosphere free bias estimates as a function of time for the time interval 40000 70000 Show in the same graph 1 ALL satellites 2 PRN16 and 3 PRN21 see Plot HW5 d Note The GUI can be graph py f amb out x2 y3 used instead of the f amb out X2 y3 C 1 16 l PRN16 graph py command f amb out x2 y3 c 1 21 1 PRN21 xn 40000 xx 70000 yn 10 yx 10 gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Tutorial associated to the GNSS Data Processing book 119 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares HW5 Analyze the carrier phase biases convergence in the kinematic PPP positioning 10 PRN16 PRN21 Comments Fam a Large peaks appear in the carrier phase re M M 59 biases due to massive cycle slips dE yv Satellite tracking loses happen MEME periodically after each revolution BENI These satellite loses produce massive Plot HW5 b cycle slips which leads to a global 38000 39000 40000 41000 42000 43000 44000 reinitialization of carrier phase biases in the navigation Kalman filter
21. associated to the GNSS Data Processing book 88 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia Mode 3 Dual freq LC PC carrier and code with precise orbits amp clocks A Answer to Question 7 Which is the improvement in precise orbits and clocks accuracy regarding the broadcast case e Broadcast orbits and clocks are accurate at the level of few meters Precise orbits and clocks IGS products are accurate at few centimeter level see HW4 A Answer to Question 8 How do carrier phase measurements allow to improve the accuracy Code measurements are unambiguous but noisy meter level measurement noise Carrier measurements are precise but ambiguous few millimetres of noise but with an unknown bias that can reach thousands of kilometres e The carrier phase biases are estimated in the navigation filter along with the other parameters coordinates clock offsets etc If these biases were fixed then measurements accurate at the level of few millimetres would be available for positioning However some time is needed to decorrelate such biases from the other parameters in the filter and the estimated values are not fully unbiased A Homework A HW4 Assess the broadcast orbits and clock accuracy using the precise products as the truth amp gA GE U P C a C ku Tutorial associated to the GNSS Data Processing book 89 Re
22. clocks A Answer to Question 1 Is it reasonable to disable the tropospheric and ionospheric corrections e Troposphere The troposphere is the atmospheric layer placed between Earth s surface and an altitude of about 60 km GRACE A satellite is orbiting at about 450 km altitude thence no tropospheric error is affecting the measurements lonosphere The ionosphere extends from about 60 km over the Earth surface until more than 2000 km with a sharp electron density maximum at around 350 km GRACE A satellite orbiting at about 450 km altitude is less affected by the ionosphere than on the ground but nonetheless a few meters of slant delay could be experienced On the other hand as the correction from Klobuchar model is tuned for ground receivers its usage could produce more harm than benefit see HW7 Homework A HW1 Assess the ionospheric delay on the GRACE A satellite measurements Compare with the Klobuchar model corrections gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia aC ku Tutorial associated to the GNSS Data Processing book Q D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Mode 1 Single frequency C1 code with broadcast orbits amp clocks A Answer to Question 2 In this approach is it necessary to introduce an additional model term to account for the relativity effect on LEO satellite e GRACE A clock is affected by general an
23. gj gan Computer credits txt F Wg u p aaa HAMID LEN E po Me ae 5 esa YLAL ud http www gage es na UAE e eae ei em glab s Home EM Positioning Analysis Input Preprocess Modelling y Filter Terminal Lg g r GNSS Formats L 7 a NW PZP amp glab gage File Edit View Terminal Help To run a command as administrator user root use sudo lt command gt See man sudo root for details glab gage i Console oN F A of 7 FPA e d Py P T Y fy ne ASIronomy Ww ULOMAaAtLiCsS searcn LTO up oj y Iniversity of Catalonia UPC SW g gLAB Version 2 0 0 f glab gage s ui L 31 OVERVIEW Y Introduction Y The gLAB tool suite Y Examples of GNSS Positioning using gLAB Y Laboratory session organization LABORATORY Session Y Starting up your laptop Basic Introductory laboratory exercises Ex1 Ex2 A Medium Laboratory Work Project LWP Kinematic positioning of a LEO satellite A Advanced Homework amp gAGE UI C Tutori Research group of Astronomy amp Geomatics J Technical University of Catalonia t Sanz Subira al associated to the GNSS Data Processing book 32 irana J M Juan Zornoza M Her ajares nandez P Basic Introductory laboratory exercises XX NR Exercise 1 Model components analysis for SPP his exercise Is devoted to analyze the different model components
24. i il digi a sii meters F r 7 PE M ru a H E 5 Pr sE M jest s dup egi maip ii th siis Plot HWA ct 0 10000 20000 30000 40000 50000 60000 70000 80000 9000 time s 0 10000 20000 230000 40000 50000 60000 70000 80000 90000 time 5 id li jl BT gne ao e i i tits l ni ias CELA dt 05 1555 20000 30000 40000 ET 60000 70000 30000 90000 time 5 B gA GE U P C Tutorial associated to the GNSS Data Processing book Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares 117 Technical University of Catalonia HW4 Broadcast orbits and clocks accuracy assessment using the IGS precise products as the accurate reference i e the truth GPS NOM Precise em APEI Radial error F ALL ePRN16 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time 5 GPS Broadcast Precise BRD APC Cross Track eerror jii gs it i liii ibi iii Sii a i pis E i am n te s im E ii il iis zit u l ii ii T i Ja 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 ime s 9 gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia 1 e at 32 MM linii al OM K A EHEH KIHTE p ii ht de in Zn in A t ts H etat AE a dk a E uet uit t i o t n nail ni tee i vets Pri n Hn ni is T uU de ii u 2 98 0 2 e 98 i ott 9 e m EN Sa e o 4 a
25. noise and multipath 1 Using the meas txt file generated before with the MEAS message data format Id YY Doy sec GPS PRN el Az N list C1C L1C CiP L1P C2P L2P 12 3 4 5 6 x x 9 10 11 xx 13 14 15 16 177 Compute P1 code noise and multipath as M PI L 2 _ L1 L2 y Z gawk BEGIN g 77 60 2 print 6 4 13 14 2 14 16 g 1 meas txt gt P1 txt 2 From previous P1 txt file Plot the P1 code noise and multipath for time interval 43000 67000 Show in the same graph 1 ALL satellites 2 PRN16 and 3 PRN21 see Plot HW3 b graph py f P1 txt x2 y3 s cl y 1 ALL f P1 txt c 1 16 x2 y3 so cl r 1 PRN16 f P1 txt c 1 21 x2 y3 so cl g 1 PRN21 xn 43000 xx 67000 yn 8 yx 28 amp gA GE U P C ac ku Tutorial associated to the GNSS Data Processing book 112 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia HW3 Code measurements noise assessment C1 P1 P2 and PC i O C The next commands compute the P2 code noise and multipath 1 Using the meas txt file generated before with the MEAS message data format Id YY Doy sec GPS PRN el Az N list C1C L1C C1P L1P C2P L2P 12 3 4 5 6 x x 9 10 11 xx 13 14 15 16 Compute P2 code noise and multipath as gawk BEGIN g 77 60 2 print 6 4 15 16 2 g 14 16 g 1 meas txt gt P2 txt 2 From previous P2 txt fi
26. of Astronomy amp Geomatics Technical University of Catalonia Plot Select SOLIDTIDES http weww gage es meters 2d Model Solid Tides Kinem PPP 90000 60000 70000 80000 0 10000 20000 30000 40000 50000 time s oolid Tides plot Note Use the gLAB out file In gLAB1 out file this model component was switched off 63 Tutorial associated to the GNSS Data Processing book J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Example of model component analysis Solid Tides gLAB Version 2 0 0 gLAB Preferences About C sAGEU esa Positioning Analysis Modelling Options Precise Products Data Interpolation vV Satellite clock offset correction x f Orbit Interpolation Degree 10 v Consider satellite movement during signal flight time v Consider Earth rotation during signal flight time Clock Interpolation Degree 0 v Satellite mass center to antenna phase center correction Receiver Antenna Phase Center Correction vi Receiver antenna phase center correction Specify Read from ANTEX vi Receiver antenna reference point correction v Relativistic clock correction orbit excentricity e a u lonospheric correction v Tropospheric correction Simple Nominal v Niell Mappi me configuration v P1 Cl correction Flexible v v Wind up correction Carrier phase only vi Solid tides correction O r Vi Relativistic path range correctio
27. offset corrections have to be applied What about the solid tides correction e Wind up correction Wind up only affects the carrier phase measurements but not the code ones This is due to the electromagnetic nature of circularly polarised waves of GPS signals The correction implemented in gLAB only accounts for the GPS satellites movement relative to a receiver An additional correction to account for the GRACE A motion along its orbital path could also be included but since most part of this effect will be common for all satellites it will be absorbed by the receiver clock offset estimation GPS satellite antenna phase center Precise orbits and clocks of IGS products are relative to the GPS satellite mass centre unlike the broadcast ones which are relative to the satellite antenna phase centre APC Thence an APC offset vector must be applied e Solid tides correction No Earth s Solid Tides corrections are needed because the rover is not on the ground B gA GE U P C a C ku Tutorial associated to the GNSS Data Processing book 91 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 4 Single freq with L1 C1 GRAPHIC comb and precise orbits amp clocks HEN Example of computation with gLAB Code and Carrier precise orbits amp clocks Single frequency GRAPHIC Complete the steps from previous
28. plot can be also generated in console mode as follows see graph py help graph py f gLAB out c 1 INPUT x4 y 11 12 1 ALL f gLAB out c 1 INPUT amp 6 16 x4 y 10 9 so 1 PRN16 P2 P1 f gLAB out c 1 INPUT amp 6 16 x4 y 11 12 so 1 PRN16 L1 L2 xn 43000 xx 67000 yn 10 yx 15 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia amp gA GE UPC aC ku p Tutorial associated to the GNSS Data Processing book 105 HW1 Assessing the ionospheric delay on the GRACE A satellite ee MEINE Working in console mode The next commands compute the ionospheric delay from C1 L1 measurements 1 Using the configuration file meas cfg read the RINEX and generate the MEAS message with data format Id YY Doy sec GPS PRN el Az N list C1C L1C C1P L1P C2P L2P 1 2 3 4 5 6 x x 9 10 11 xx 13 14 15 16 Execute gLAB linux input cfg meas cfg input obs graa0800 070 gt meas txt 2 From file meas txt compute the ionospheric delay as I Y C1 Ll bias gawk print 6 4 11 14 2 meas txt gt I1 txt 3 From previous file plot the ionospheric delay for the time interval 43000 67000 Show in the same plot 1 ALL satellites 2 PRN16 and 3 PRN21 see Plot HW1 b in next slide graph py f I1 txt x2 y3 s cl y 1 ALL f I1 txt c 1 16 x2 y3 so cl r 1
29. products with centimeter level accuracy gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia aC ku Tutorial associated to the GNSS Data Processing book 52 D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Exercise 1 SPP Model components analysis T NEU positioning error SPP Full model Vertical positioning error SPP Horizontal positioning error SPP H P 150 Full model Sat coord in recept time instead of emission jo ne een eee eee a ee abuses e eSat coord in recept time instead of emission e eFull model re es z Seen bonds m ATTE F TN E NR b error m o Up error m o SINN Sige been denne D ME NM DUE pep augus sene P AE gLAB out 128000 Model Model Sat cood in reception time instead of emission SPP 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 80000 90000 9050 100 50 0 50 100 150 time s East error m Satellite coordinates in reception time instead of EY emission time A POSUER AM ASIN SS R Unset both in gLAB Model URP I ARM m aol WALA WALA ANAS Satellite movement iO Ae a Aa QS idi i amp MAA during signal flight time Earth rotation during signal flight time 20000 30000 40000 50000 60000 70000 NEU error SPP Coordinates in reception time vs emission 2nd May 2000 150 North error East error U
30. reduce computation time M Relativistic clock correction orbit excentricity gLAB has found the following errors please correct them MEER pt puta C lonospheric correction before processing again vp 4 S A RS Tropospheric correction Simple Nominal v Niell Mapping v SES l l l MODEL INPUT Receiver Antenna Phase Center source is set Melbourne W bbena F1 F2 Umm P1 P2 correction Receiver Antenna Reference Point Correction as ANTEX but no ANTEX file is found Please include one in P1 C1 correction Flexible v By ORO hom TENE Input section Z L1 C1 difference F1 Configure Wind up correction Carrier phase only Solid tides correction Relativistic path range correction S Save Config Run gLAB ill ie SPP Template PPP Template M gA GE U C Tutorial associated to the GNSS Data Processing book 8 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia The gLAB Tool suite ry gt Version 2 0 0 J A Students Newcomers Easiness of use Intuitive GUI e Explanations Tooltips over the different GUI options m Guidelines Several error and warning messages ns Templates for pre configured processing TEST k factor Save Config SPP Template PPP Template Run gLAB Professionals Experts Powerful tool with High Accuracy Positioning capability e Fastto c
31. values are not fully unbiased gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Backup Tutorial associated to the GNSS Data Processing book 61 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Exercise 2 PPP Model components analysis GPS Broadcast Precise BRD APC Radial error GPS Broadcast Precise BRD APC Along Track error Es See T x T cer Orbits amp clocks 3 3 3 ePRN16 sis 3 m 3 X With S A on clocks were y xd y degraded several tens of meters i M eis mus xus gest Spin HERR AER Si d dian tus ije a aih ji iE i ts ae st EE DA TE ie ste m i Session 3b Ex4 2nd May 2000 Broadcast Precise nu IM Ru duni d n dm e eOrbit 3D error e e Clock error meters Dead im Puis um n ait ee teet yet annt oes 10000 20000 30000 40000 50000 60000 70000 80 20000 30000 40000 50000 60000 70000 80000 90000 time 5 time 5 z S A off GPS Broadcast Precise BRD APC Cross Track eer PS Broadcast Precise BRD APC Clock error ALL ALL gtere teres s pore inte mate insi de m oe be ee ue Od HEN wt tee aer MA ss m ecce TL eg i irs ates Be Se e sepcees B siili T he a xm e at n Bs bie Spat Eil s oes ipit d di i E serpa 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 e e Fe ais sts eias x scil um Mist eae ETH iui a ae 7 Under S A off
32. 000 time 5 amp gA GE U P C Tutorial associated to the GNSS Data Processing book 83 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 2 Dual frequency PC code with broadcast orbits amp clocks A Answer to Question 4 Why the solution is noisier than the previous one with C1 code ee aeu E TIY e gj e Thence assuming uncorrelated P1 P2 measurements with equal noise o it follows O 30 The iono free combination of codes P1 and P2 is computed as Answer to Question 5 Discuss the pros and cons of the ionosphere free combination of codes PC e Combination PC removes about the 99 9 of ionospheric delay one of the most difficult error sources to model but two frequency signals are needed On the other hand PC is noisier than the individual codes C1 P1 or P2 see HW3 Answer to Question 6 How could the performance be improved e Smoothing the code with the carrier and or using precise orbits and clock products as well Homework A HW3 Assess the measurement noise on the C1 P1 P2 and PC code measurements amp gA GE U P C ac ku Tutorial associated to the GNSS Data Processing book 84 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 3 Dual freq LC PC carrier and code with precise orbits amp
33. 2 e 4 tte H 1 ee oY ops aot 0 10000 20000 36000 40000 50000 60000 70000 80000 90000 time s GPS Broadcast Precise BRD APC Clock error in tps ii xd D eem i od Ten s vine cee ie ss i pus B yid it e ihia 2 a i sir it st in wi is vue T i irs ze eus i si cas A in it m ROC is eeu ves E i e te o P 2 c 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s Comments The previous computations have been repeated but using the ANTEX file gps brd atx instead of 1gs05 1402 atx This new ANTEX file contains the GPS antenna phase center offsets used by the GPS ground segment not the IGS ones e Notice that the biases in the radial component have disappeared meters 10000 20000 30000 a0000 a IE A 80000 i ne s GPS Broadcast Precise BRD alimi SISRE Plot HWA 22 faa Tutorial associated to the GNSS Data Processing book 118 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares HW5 Analyze the carrier phase biases convergence in the kinematic PPP positioning n Complete the following steps 1 Configure gLAB as in Mode 2 for the Kinematic PPP positioning Activate the Print POSTFIT messages in the OUPUT panel see message content in the Tooltip or executing gLAB linux messages 2 Run gLAB The program will output the file gLAB out 3 From gLAB out grep the POSTFIT message and generate the file
34. 5 e oL e E o a 2 Km M m cM TE PUDE N o Ww o 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s 18000 20000 30000 40000 50000 60000 70000 80000 90000 East error m NEU error SPP No Tropo corr 2nd May 2000 Model Tropo corrections SPP 25 North error East error UP error off Zoom 7 Iropospheric ecg re s cei 4 correction blind model 100 S A is ER hr E z Ape tn rie Tropospheric and vertical sete Jan ah iY cot st error are highly correlated A displacement of vertical component appears when neglecting tropo corrections error m o meters 50 100 gLABL out 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 10000 20000 30000 40000 50000 060000 70000 80000 90000 time s time s 150 amp e gA GE U P C Tutorial associated to the GNSS Data Processing book 45 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Exercise 1 SPP Model components analysis Tropospheric delay The troposphere is the atmospheric layer placed between Earth s surface and an altitude of about 60 km The effect of troposphere on GNSS signals appears as an extra delay in the measurement of the signal travelling from satellite to receiver The tropospheric delay does not depend on frequency and affects both the pseudor
35. A GE U P C Tutorial associated to the GNSS Data Processing book 2 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia LWP Kinematic positioning of a LEO satellite A The following preliminary questions are posed e Could a LEO satellite like GRACE A be kinematically positioned as a rover receiver i e car aircraft Why e Would both Standard and Precise Positioning be achievable Note The HINEX file graae800 070 contains GPS dual freq Measurements e Which model components should be set for each positioning mode Relativistic correction poem correction lonospheric correction Instrumental delays TGDs Solid Tides correction Antenna phase centre corrections Others n case of successful positioning which accuracy is amp gA GE U P C Tutorial associated to the GNSS Data Processing book 73 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia LWP Kinematic positioning of a LEO satellite A The following positioning modes are proposed to be explored Code positioning broadcast orbits 1 Single frequency C1 code and no ionospheric corrections 2 Dual frequency PC code combination i e ionosphere free combination e Code and carrier positioning precise orbits and clocks 3 Dual frequency PC LC comb
36. AB gAGEUPC Positioning Analysis 2 SaveasgLAB1 out EN the associated Examine Output Fil Examine L Messages Messages V Print INFO Messages v Print INFO Messages v Print CS Cycle Slip Messages n t h e Defa u It v Print CS Cycle Slip Messages et O ut p u t i e vi Print INPUT Messages v Print INPUT Messages eee configuration the Notice that the gLAB out e a as file contains the processing p I gLAB1 out Print FILTER Messages zl Output Tile was acuiits with the FULL gLAB out model as it was set in the Save Config SPP Template PPP Template Run gLAB default C O n f g u r at i O n l Config SPP Template PPP Template 3 gA GE U P C Tutorial associated to the GNSS Data Processing book 37 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia 2 8 mW 072 8 amp 1j Print OUTPUT Messages NEU Position Error plot from gLAB1 out Cesa GLAB sacevec Positioning Analysi NEU positioning error NEU error SPP No lona corm 2nd May 2000 Horizontal positioning error Zenith Tropospheric Delay lonospheric combinations 150 North error Satellite skyplot Carrier phase ambiguities Measur Multipath Noise i i i ENG Ea st error l z UP error lO0L ILL oe T LEE f 1 qe gt
37. Developed by gAGE Research group of Astronomy amp GEomatics Technical University of Catalonia UPC Introduction A This practical lecture is devoted to analyze and assess different issues associated with Standard and Precise Point Positioning with GPS data A The laboratory exercises will be developed with actual GPS measurements and processed with the ESA UPC GNSS Lab Tool suite gLAB which is an interactive software package for GNSS data processing and analysis A Some examples of gLAB capabilities and usage will be shown before starting the laboratory session All software tools including gLAB and associated files for the laboratory session are included in the USB stick delivered to lecture attendants A The laboratory session will consist in a set of exercises organized in three different levels of difficulty Basic Medium and Advanced Its content ranges from a first glance assessment of the different model components involved on a otandard or Precise Positioning to the kinematic positioning of a LEO satellite as well as an in depth analysis of the GPS measurements and associated error sources GE U P C Tutorial associated to the GNSS Data Processing book 4 ich gro s of As tronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares e chnical Un dis of Catalo gt The gLAB tool suite C ooqle amp The gLAB Tool suite A The GNSS Lab Tool suite gLAB is
38. NEU positioning err onospheric combinations Dilution Of Precision Satellite skyplot Carrier phase aml 1r Dilution Of Precisio r Multipath Noise Model components Prefit residuals Postfit residu Model components Prefit residuals k comparison Global Graphic Parameters A MM MM Title Vertical positioning error X label time s Y label jeri Global Graphic Parameters Title Vertical positioning error X lab time s X max Plot Nr 3 Plot Nr 4 1 OUTPUT e DSTAU v 20 3 Examine Dotted Line v Blue Full Model gAGE UPC Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Tutorial associated to the GNSS Data Processing book 39 Horizontal Position Error plot gLAB out gLAB1 out gLAB Version 2 0 0 nag T A gLAB T We rsion 2 0 0 Horizontal positioning error SPP Preferences C o e full model Positioning Analysis Prererent Templates Positioning Analysis fesa About NEU positioning error Horizontal positioning error Zenith Tropospher Templates me b f NEU positioning lonospheric combinations Dilution Of Precision Satellite skyplot Carrier phase a
39. P error off Zoom S A error m o gLAB1 out ia 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 8000 time s 30000 40000 50000 60000 70000 80000 90000 time s 20000 9 gAGE UPC Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Tutorial associated to the GNSS Data Processing book 53 Exercise 1 SPP Model components analysis gLAB implements the following well known algorithm to compute the satellite coordinates both from broadcast message or IGS precise orbits 1 From receiver time tags I e reception time in the receiver clock compute emission time in GPS system time T emission t Tp C1 c dt Notice that code pseudorange is a link between transmission and reception times in the satellite and receiver clocks C1 c At c t T4 te s TS dtS satellite clock offset c light speed in vacuum 2 Compute satellite coordinates at emission time 7 emission T emission orbit 3 Xs Ysat Zsa 3 Account for Earth rotation during traveling time from emission to reception At CTS reference system at reception time is used to build the nav equations X381 YS ZS reIreception 13 e A X581 YS 7580 ot stemission CTS emission Q aes GE U P C ac ku Tutorial associated to the GNSS Data Processing book 54 rch gro up of Astronomy amp Geomatics D J Sanz Subirana J M Ju
40. Print MODEL Messages Print PREFIT Messages MEI Ex NNI Print FILTER Messages i Field 15 L1C prealigned in meters Save Config Field 16 L7Q prealigned in meters RungLAB Show Output Field 17 L8Q prealigned in meters For GLONASS GLO Field 8 C1 C1C e Field 9 C2 C2C Field 10 L1 L1P prealigned in meters Field 11 L2 L2P prealigned in meters For GEO e Field 8 C1 C1C e Sample INPUT 2006 200 0 00 GPS 19 1 23119003 9020 23119002 6110 23119004 0750 23119002 7507 23119004 0925 amp gA GE U P C a C ku Tutorial associated to the GNSS Data Processing book 1 3 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Note This configuration will provide Plot 1 L1 L2 as a function of time for ALL sat Plot 2 L1 L2 as a function of time for PRN16 Plot 3 P2 P1 as a function of time for PRN16 HW1 Assessing the ionospheric delay on the GRACE A satellite gLAB Version 2 0 0 xem LAB gLAB Version 2 0 0 gE O gAGEU http www gage es fesa About Positioning Y e S a BR 2 Templates ur c a Lum e 10 Ee http www ona NEU Zenith Tropospheric Delay lonospheric combinations ncm ae a Dilutiuis Ge recur aS 28y yr Carrier phase ambiguities Measur Multipath Noise M
41. Results gLAB Version 2 0 0 Gosa gLAB 76 saGEur http www gage es geeeo N Preferences About NEU positioning error SPP North error East error UP error eeceececedecccecccccoechececcsccccedecccecccccccboececcccccedeccccccc d odR rr i SII Positionir amp Analysis e e NEU positioning error Horizontal positioning error Zenith Tropospheric Delay lonospheric combinations al 4 P i T Dilution Of Precision M Satellite skyplot Carrier phase ambiguities Measur Multipath Noise Model components Prefit residuals Postfit residuals Orbit and Clock comparison Global Graphic Parameters Title NEU positioning error X label time s Y label error m Clear Apes cen eR CIE ME Horizontal Kinematic positioning error SPP Automatic Limits X min X max Y min Y max Positioning with few meters of error is achieved in kinematic SPP mode Satellite skyplot Heceiver navigated as a rover in pure kinematic mode North error m e Single frequency C1 code is used TUAM Paesi enum e Broadcast orbits and clocks ss EM amp gA GE U P C Tutorial associated to the GNSS Data Processing book 19 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical Univers
42. SINEX position files Pre processing module Carrier phase prealignment Carrier phase pseudorange consistency check Cycle slip detection customizable parameters Melbourne W bbena Geometry free CP combination L1 C1 difference single frequency Pseudorange smoothing Decimation capability On demand satellite enable disable Elevation mask Frequency selection Discard eclipsed satellites Modelling module Fully configurable model oatellite positions oatellite clock error correction oatellite movement during signal flight time Earth rotation during signal flight time oatellite phase centre correction Receiver phase centre correction frequency dependent Relativistic clock correction Relativistic path range correction lonospheric correction Klobuchar Tropospheric correction Simple and Niell mappings Simple and UNB 3 nominals Ditferential Code Bias corrections Wind up correction Solid tides correction up to 2 9 degree gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Backup Tutorial associated to the GNSS Data Processing book 11 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Filtering module e Able to chose different measurements to process 1 or more with different weights This design could be useful in future Galileo processing where processing with different measurements may b
43. Title Horizontal sitioning err X label East error m Y label Ne 3 wi Global Graphic Parameters Clear Automatic Limits ymin 0 E 4 Title Horizontal positioning err Webel East error m Y label wilhserror m Automatic Limits Plot Nr 3 Individual Plotis Conffqur atre Plot Nr 1 Plot Nr 2 Plot Nr 3 Plot Nr 4 Blue HUTUT w 1 0UTPUT QUTPUT DSTAE 77 DSTAN 18 Y Column DSTAN Model 1 OUTPUT amp gA GE U P C Tutorial associated to the GNSS Data Processing book 66 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Exercise 2 PPP Model components analysis 2c Vertical positioning error Kinem PPP 2c Horizontal positioning error Kinem PPP s No Solid Tides corr gLAB1 out nme S lid Tid 0 4 olid Tides It comprises the Earth s T crust movement and N thence receiver coordinates 3 b variations due to the 5 i gravitational attraction forces produced by external ZEN bodies mainly the Sun and AB out gL 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 053 4 2 0 1 0 0 0 1 0 2 0 3 0 4 e OO n Time s East error m 2d Model Solid Tides Kinem PPP n a 1 1 WW Solid Tides O Moon T D NE E These effects do not affect the eR e ruv GNSS signals bu
44. a M Hernandez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia Positioning Analysis epoch HW1 Assessing the ionospheric delay on the GRACE A satellite JLAB Version 2 0 om Configure gLAB as in Mode 1 and _ O gAGE UPC complete the following steps http www gage es TL Cesa INPUT messages Se aan i carana a mananan b anh ear E Upute au Print INPUT Message Print MODEL Message see message content in the Tooltips Run gLAB Field 1 INPUT e Field 3 Doy Output Destination Field 4 Seconds of day Output File gLAB out Field 5 GNSS System GPS GAL GLO or GEO Field 6 PRN satellite identifier Messages Field 7 Arc length number of undecimated epochs after the Print INFO Messages L last cycle slip ge For GPS Field 8 C1 C1C e Field 9 P1 C1P e Field 10 P2 C2P Field 11 L1 L1P prealigned in meters Field 12 L2 L2P prealigned in meters For Galileo GAL e Field 8 C1A e Field 9 C1B Print POSTFIT Messages Field 10 C1C e Field 11 C7Q e Field 12 C8Q Print OUTPUT Messages e Field 13 L1A prealigned in meters Field 14 L1B prealigned in meters C Print CS Cycle Slip Me Make plots Analysis section Click on the preconfigured lonospheric combinations option Complete the Plot1 Plot2 Plot3 panels configuration as indicated in the next slide V
45. a Ref Point O Tropospheric correction Parameters z S lonospheric already disabled EEUU Np M ward fitering cumin P1 P2 already disabled wee C0 Uem Switch to ee Tropospheric eme 01009 1 Kinematic Save Config e Solid Tides correction Save Config SPP Template PPP Template BungLAB Show Output amp e gA GE U P C Tutorial associated to the GNSS Data Processing book 86 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Mode 3 Dual freq LC PC carrier and code with precise orbits amp clocks Example of computation with gLAB Code amp Carrier precise orbits amp clocks Dual frequency LC PC 1 Convert the output gLAB out file to sp3 format Execute in Console out2sp3 gLAB out orb sp3 gLAB Version 2 0 0 2 Compare the computed coordinates orb sp3 with reference GRAA 7 080 sp3 Preferences About Note Use the configuration file dif cfg Positioning Analysis Output Destination Output File gLAB out Examine p Deis orca Disable all messages LI z v 1 Hun g LAB except tame Print INPUT Messages Print MEAS Message Print MODEL Messages Print EPOCHSAT Messages S Print INFO Messages 2 Generate ee Print OUTPUT Messages ooa 7 d
46. an Zornoza M Hern ndez Pajares eei cal Un E Gc Exercise 1 SPP Model components analysis Range variation Ap Pemission Preception Reception Barcelona Spain 2005 529 Reception Time instead Emission time f3 E Geometric range variation 10000 20000 soooo 40000 Boo00 60000 Yoooo 0000 Time GPS seconds of day meters Note Preception S computed unsetting in gLAB Satellite movement during signal flight time Earth rotation during signal flight time 40000 Time GPS seconds of day amp gA GE U P C ac ku D Tutorial associated to the GNSS Data Processing book 55 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Exercise 1 SPP Model components analysis 150 NEU positioning error SPP Full model a es error m o ducc ius ugue doen mus oe ee Deed 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s NEU error SPP No Earth rot 2nd May 2000 150 North error East error l A UP error 1001 7 urne SUD CEA ic dp error m o aipee eie eee entis imei eee eee gLAB1 out 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s 150 off Zoom S A Vertical positioning error SPP Horizontal positioning error SPP glAB1 out Mee eer aan RM TER RE i Spee bestem T EEI E 20 L eeelellle
47. an interactive multipurpose educational and professional package for GNSS Data Processing and Analysis A gLAB has been developed under ins ESA EUR n contract N P1081434 Main features High Accuracy Positioning capability Fully configurable Easy to use e Access to internal computations amp gA GE U P C Tutorial associated to the GNSS Data Processing book 6 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Researc h aly or Desi iens die Geomatics Technical Un ity of Catalo The gLAB Tool suite A gLAB has been designed to cope with the needs of two main target groups e Students Newcomers User friendly tool with a lot of explanations and some guidelines Professionals Experts Powerful Data Processing and Analysis tool fast to configure and use and able to be included in massive batch processing amp gAGE UI C Tutori Research group of Astronomy amp Geomatics J Technical University of Catalonia t Sanz Subira na jares al associated to the GNSS Data Processing book T irana J M Juan Zornoza M Hern ndez Pajare The gLAB Tool suite A Students Newcomers Easiness of use Intuitive GUI e Explanations Tooltips over the different options of the GUI e Guidelines Several error and warning messages Templates for pre Mii abs processing gLAB Version 2 0 0 DLABI 8 vee gLAB Version 2 0 0 Ix http www
48. ange code and carrier phases in the same way It can be modeled by e An hydrostatic component composed of dry gases mainly nitrogen and oxygen in hydrostatic equilibrium This component can be treated as an ideal gas Its effects vary with the temperature and atmospheric pressure in a quite predictable manner and it is the responsible of about 90 of the delay A wet component caused by the water vapor condensed in the form of clouds It depends on the weather conditions and varies faster than the hydrostatic component and in a quite random way For high accuracy positioning this component must be estimated together with the coordinates and other parameters in the navigation filter GE U P C ac ku Tutorial associated to the GNSS Data Processing book 46 rch gro up of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares fe chnical Un itn of Catalo Exercise 1 SPP Model components analysis NEU positioning error SPP Full model Vertical positioning error SPP Horizontal aaa error err North error East error 5 UP error error m Up error m ZLAB out j 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 ime s 18000 20000 30000 40000 50000 60000 70000 80000 90000 East error m NEU error SPP No Rel Clock 2nd May 2000 Model Relatvistic clock correction orb excent SPP North error East error
49. ase center correc V Receiver antenna reference point corr Is Specify Read from R correction SPP Template PPP Template Run gLAB Show Output Preferences About Notice that the gLAB out file contains the processing Output Fil results with the FULL ien v Print INFO Messages Examine model as it was setin the sc Set output file v Print INPUT Messages d f l t f t Print MEAS Message e au con IQ U a lion v Print MODEL Messages as Print EPOCHSAT Messages Print PREFIT Messages Print POSTFIT Messages g AB l e O u Print FILTER Messages 4 27 8 8 Print OUTPUT Messages Make plots as in previous 3 exercises see slides 40 42 m I Tutorial associated to the GNSS Data Processing book 64 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Vertical Position Error plot from gLAB out gLAB1 out gLAB Version F Oo a 2c Vertical positioning error Kinem PPP T b Full model No Solid Tides corr esa Preferences Pa Saar i Positioning Analysis itioning Analysis Templates Positioning y Templates NEU positioning error Horizontal positioning error Zenith Tropospher NEU positioning error lonospheric combinations Dilution Of Precision Satellite skyplot Carrier phase amt Dilution Of Precision Menteur Multipath Noise Model components Prefit residuals Postfit residu Mode
50. broadcast differential code biases inaccuracy A Answer to Question 16 No ionospheric corrections have been applied in this run What would happen if the Klobuchar model is applied e In general the performance will degrade As commented before the correction from Klobuchar model is tuned for ground receivers only removes about the 50 of ionospheric delay and its usage can produce more harm than benefit see HW6 A Homework A HW6 Apply the Klobuchar model and discuss the results A HW7 Generate a file with the satellite track in a Earth Fixed Earth Centered reference frame to be viewed with Google earth e gA GE U P C ac ku Tutorial associated to the GNSS Data Processing book 98 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia OVERVIEW Y Introduction v The gLAB tool suite Y Examples of GNSS Positioning using gLAB Y Laboratory session organization LABORATORY Session Y Starting up your laptop Y Basic Introductory laboratory exercises Ex1 Ex2 Y Medium Laboratory Work Project LWP Kinematic positioning of a LEO satellite Advanced Homework amp gA GE U P C Tutorial associated to the GNSS Data Processing book 99 Research group of Astronomy amp Geomatics J irana J M Juan Zornoza M Her ajares Technical University of Catalonia t Sanz Subi n ndez P Proposed Homework exercises A
51. cat Postfix kml grace track kml 3 View the file with Google 124 Thanks for your attention amp gA G E U P C Tutorial associated to the GNSS Data Processing book 125 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia Acknowledgements A The ESA UPC GNSS Lab Tool suit gLAB has been developed under the ESA Education Office contract N P1081434 A The data set of GRACE A LEO satellite was obtained from the NASA Physical Oceanography Distributed Active Archive Center at the Jet Propulsion Laboratory California Institute of Technology The other data files used in this study were acquired as part of NASA s Earth Science Data Systems and archived and distributed by the Crustal Dynamics Data Information system CDDIS To Pere Ramos Bosch for his fully and generous disposition to perform gLAB updates in his afterhours To Adria Rovira Garcia for his contribution to the edition of this material and gLAB updating To Dagoberto Salazar for the English reviewing and integrating this learning material into the GLUE aes G E U P C Tutorial associated to the GNSS Data Processing book 126 ich gro s of As tronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares e chnical Un dis of Catalo
52. ceived as self learning work a detailed guide is provided in the slides pdf file to develop the exercises A A set of questions is presented and the answers are also included in the slides A Teachers will attend individual or collective questions that could arise during exercise resolution o gA GE UPC ich gro s of As tronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares NS chnical Un dins of Catalonia Tutorial associated to the GNSS Data Processing book 24 Laboratory session organization A The exercises are organized in three different levels of difficulty The student can choose the level of exercises to do although at least an introductory exercise is recommended to learn basic gLAB usage A 1 Basic Introductory exercises 1 amp 2 They consist in simple exercises to assess the model components for otandard and Precise Point Positioning Background information slides are provided Summarizing the main concepts associated with these exercises Brief summaries of fundamentals in backup slides amp gA GE U P C Tutorial associated to the GNSS Data Processing book 25 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Laboratory session organization A 2 Medium Laboratory work project It consists in the kinematic positioning of a Low Earth Orbit satellite Different posi
53. cking Terr 3 network Precise Products c 12 February 2007 SP3 Verson C htmi i SP3 format tor GNSS orbit and clock solutions t t ANTEX format for Phase Center Offsets PCOS and Antenna 13 20 September 2006 ANTEX v1 3 htm Phase Center Variations PCVs of geodetic GNSS antennae Station Clock Reference QAGE Learming Material More details at http www gage es gLAB amp gA GE U P C Tutorial associated to the GNSS Data Processing book 17 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Example 1 Standard Point Positioning SPP SPP Template Kinematic positioning with single freq C1 code z 3 broadcast orbits and clocks 1 Select the SPP Template 2 Upload the RINEX files E E p a Measurement roap1810 090 SNET NER O Precis Navigation brdc1810 09n Orbit a bibens ne home gLAB brdc1810 09n 3 RUN gLAB 4 5 jaume work lle Q A TENE x e 1file Precise 2 files Default output file gLAB out Note Reference coordinates are from RINEX GE U P C Tutorial associated to the GNSS Data Processing book 18 rch gro up o of As tronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares NS chnical Un dins of Catalo Example 1 Standard Point Positioning SPP A Plotting
54. clocks Example of computation with gLAB Code amp Carrier precise orbits amp clocks Dual frequency LC PC Version 2 0 0 23 E3 P es 4 M a C B seure Cesa a a http Ar gage t i X z http www gage es Preferenc S t D 2 fil Preferences linn ou Positioning m e recise es itioni is Input Files iti RINEX Observat io n File home gLAB graa0800 070 VI Show ANTEX File Station Data GNSS Satellite Selection v Data Decimatiog s 30 Satellite O Elevation Was egrees 5 C Discar t es under eclipse condition Discar satelli Cycle sli Detection Set data decimation to 30 seconds instead of 300 to have a higher number of output samples ome gLAB igs0O5 1402 atx Orbit and Clock Source Broadcast Precise e GPS SP3 File CLK File AI None ihe gLAB cod14193 clk lonosphere Source if ac ed Geometric free CP Combi Select files graa0800 070 cod14193 sp3 cod14193 clk igs05 1402 atx C Melbourne W bbena F1 V L1 C1 difference F1 Save Config SPP Template PPP Template RungLAB Show Output gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Tutorial associated to the GNSS Data Processing book 85 J Sanz Subirana J M Juan Zo
55. configuration gL AB 99 Single frequency 1 Model Note C1C must be set Disable P1 P2 Corr due to gLAB architecture 2 Filter but itis assigned a large sigma to avoid the C1 code Single Frequency noise and ionospheric error e C1C C1 code Oc 100 meters e G1C GRAPHIC LAB Version 2 0 Og 0 5 meters 3 Run gLAB E E 4 In console mode Convert the output gLAB out file to sp3 format Execute in Console Convert the glab out orb sp3 to orb Sp3 format file 2 Compare the computed coordinates orb sp3 with reference GRAA 07 80 sp3 e Compute differences AD has found tha Following parma Template Note Use the configuration file dif cfg with reference file GRAA 07 080 sp3 3 Plot dif out file Make plots as before amp gA GE U P C Tutorial associated to the GNSS Data Processing book O2 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Mode 4 Single freq with L1 C1 GRAPHIC comb and precise orbits amp clocks GRACE A Broadcast positioning GRAPHIC Radial error GRACE A Broadcast positioning GRAPHIC Along Track error i 4 i 4 k Questions 12 Which is the main benefit of the GRAPHIC combination 10000 20000 30000 40000 50000 680000 70000 0000 90000 time 5 GRACE A Broadcast positioning GRAPHIC Cross T
56. coordinates to asses the positioning error Note the receiver coordinates were keep fixed during the data collection amp gA GE U P C Tutorial associated to the GNSS Data Processing book 15 Research group of Astronomy amp Geomatics J irana J M Juan Zornoza M He ajares Technical University of Catalonia t Sanz Subira rn ndez P We will work after the correlator Our input data are code and carrier measurements and satellite orbits and clocks Ficheros RINEX observables 2 OBSERVATION DATA G GPS RINEX VERSION TYPE RGRINEXO V2 4 1 UX AUSLIG 10 JAN 97 10 19 PGM RUN BY DATE Australian Regional GPS Network ARGN COCOS ISLAND COMMENT BIT 2 OF LLI 4 FLAGS DATA COLLECTED UNDER AS CONDITION COMMENT 0 000000000103 HARDWARE CALIBRATION S COMMENT 0 000000054663 CLOCK OFFSET S COMMENT MARKER NAME 1997 1 9 0 7 30 0000000 TIME OF FIRST OBS 1997 1 9 23 59 30 0000000 TIME OF LAST OBS END OF HEADER e RE n auslig ERVER AGEN e RI NEX FI LES ROGUE SNR 8100 93 05 25 2 8 33 2 REC 4 TYPE VERS e DORNE MARGOLIN T ANT TYPE e Pseudoranges C A P1 P2 741950 3241 6190961 9624 1337769 9813 APPROX POSITION XYZ s i 0 0040 0 0000 0 0000 ANTENNA DELTA H E N e phase tracking L1 L2 1 1 WAVELENGTH FACT L1 2 e E ot 5 Ci Li I2 P2 Pi TYPES OF OBSERV One o s Navigation data D t SNR is mapped to signal strength 0 1 4 9 multiple SNR 500 gt 100 gt 50 gt 10 gt 5 gt 0 bad n a sig 5 d
57. d special relativistic effects due to the gravitational potential and satellite soeed But this is not a problem because the receiver clock is estimated along with the coordinates Notice that this relativistic effect will affect all measurements in the same way and thence it will be absorbed into the receiver clock offset estimation A Answer to Question 3 What could be the reason for the large error peaks seen in the plots The large error peaks are associated to bad GPS LEO satellite geometries and mismodelling Notice that the satellite is moving at about 8 km s and therefore the geometry changes quickly see HW2 Also the geometry is particularly poor when GRACE A satellite is over poles Homework A HW2 Plot in the same graph the True 3D error the Formal 3D error i e the 3D sigma and the number of satellites used Analyze the evolution of the error amp gA GE U P C a C ku Tutorial associated to the GNSS Data Processing book 81 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 2 Dual frequency PC code with broadcast orbits amp clocks Example of computation with gLAB Code positioning broadcast orbits Dual frequency PC code combination Complete the steps from previous configuration 1 Modeling e Disable P1 P2 correction 2 Filter Dual Frequency e PC combinat
58. ds formats RINEX ANTEX SINEX Understanding a format description is a tough task These standards are explained in a very easy and friendly way through a set of html files 9 http gage14 upc es gLAB HTMULaunchHTML htm Described formats e Observation RINEX e Navigation RINEX e HINEX CLOCKS e SP3 Version C ANTEX A isited v Getting Started EJLatest Headlines v ar gAGE Learning Material Windows Internet Explorer DBR Gels GNSS Format Descriptions PR E Z RINEX HTML RINEX 4 X Explained Formats dp Favorites S gAGE Learning Material a A zi CLOCK DATA FILE 3 00 Format wn RINEX format for GPS and GLONASS observations Observation 211 10 December 2007 Observation Rinex v2 L1 him RINEX format for GPS and GLONASS observations 0 Observation Rinex v3 01 html RINEX format for GPS and GLONASS observations 211 10 December 2007 _ GLONASS Navigation Ranex v2 11 nim RINEX format for GLONASS Navigation Message File PS avigation Rinex v RINEX format for GPS Navigation Message File RINEX format for the complete broadcast data of Space Based Augmentation Systems SBAS IONEX format for ionosphere models determined by processing data of a GNSS tracking network mu T gt RINEX format for satellite and receiver s E Clocks 3 00 14 November 2006 RINEX CLOCKS y3 00 html determined by processing data of a GNSS tra
59. e I 100 ede IR s TD xdi NM iG 10000 20000 30000 40000 50000 60000 70000 80000 20004 time 5 gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia off Zoom S A Summary lono model component analysis Vertical positioning error SPP Horizontal positioning error SPP BLABl oufi 2 Sime TEP eerie Teeter eee Eh Up error m RAest 000 0 g 20 10000 20000 30000 40000 50000 60000 70000 4 80000 90000 20 15 10 5 0 5 10 15 20 Time s East error m Model lono corrections SPP a lonospheric correction 3p ce Mid ru IS l f broadcast Klobuchar TR lonospheric delays are larger at noon due to the higher insulation meters Large positioning errors mainly in vertical appear when neglecting iono corr 20000 30000 40000 50000 60000 70000 80000 90000 time s 18000 Tutorial associated to the GNSS Data Processing book 42 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Exercise 1 SPP Model components analysis lonospheric delay The ionosphere extends from about 60 km over the Earth surface until more than 2000 km with a sharp electron density maximum at around 350 km The ionospheric refraction depends among other things of the location local time and solar cycle 11 years First order 799 996 ionospheric delay depends 8 I on the inverse of squared
60. e desired e Fixed or elevation dependant weights per observation e Troposphere estimation on off e Carrier Phase or Pseudorange positioning e otatic Kinematic positioning full Q Phi PO customization e Able to do a forward backward processing e Able to compute trajectories no need for a priori position gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia The gLAB Tool suite Backup A Output module e Cartesian NEU coordinates e Configurable message output A Other functionalities Computation of satellite coordinates and clocks from RINEX and SP3 files e Satellite coordinates comparison mode For instance RINEX navigation vs SP3 or SP3 vs SP3 along track cross track and radial orbit errors clock errors SISRE e Show input mode No processing only parsing RINEX observation files Current version allows full GPS data processing and partial handling of Galileo and GLONASS data Future updates may include full GNSS data processing Tutorial associated to the GNSS Data Processing book 12 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares GNSS learning material package Includes three different parts allowing to follo either a guided or a self learning GNSS course e GNSS Book Complete book with theory and algorithms Volume 1 and with a Lab course on GNSS Data Processing amp Analysis Volume 2 e gLAB
61. ed in the Range linn set in Min and Position domains anei are a le A default an A baseline example of this y Geraun tO t analysis procedure for the SPP solution ionospheric correction is provided as follows he same scheme must be Sasa cut ainnise er Baas applied for all model terms Modelling Options Satellite clock offset correction Consider satellite movement during signal flight time Consider Earth rotation during signal flight time O Satellite mass center to antenna phase center correction O Receiver antenna phase center correction Receiver antenna reference point correction Relativistic clock correction orbit excentricity lonospheric correction Klobuchar Tropospheric correction UNB 3 Nominal v Simple Mapping P1 P2 correction RINEX Nav File v P1 C1 correction Flexible O Wind up correction Carrier phase only Solid tides correction O Relativistic path range correction GE U P M Tutorial associated to the GNSS Data Processing book 36 ich gro up of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Te chnical Un Mito of Catalo Example of model component analysis IONO ee E The procedure Cesa QLAB 9 explained here is Cea gLAB ene Preferences About Preferences About AAA a osetia n L Modelling Options a Modelling Options v Satell
62. erienced by the GPS signal l 1 00 hii 1 1 1 applying the Klobuchar model to the LEO n Nak ow hoon TARL Du This is due to the large error introduced z ol TUNEDR GEPPDEU PONE ETE RETRO AALEN SCENES OSEE L i re IV 4 HE HR G E A l ALAN g E LL 2g LL 11 1 if ni AUNAN uy fnis model N a TOF 90 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s GRACE A Broadcast positioning P1L1 Klob Cross Track error GRACE A Broadcast positioning PLL1 Klob 8 3 a k s H H lonospheric delay Radial 10 Along Track Cross Track e PRN16 Klob shifted e PRN21 Klob shifted e PRN16 1 2 C1 L1 PRN21 1 2 C1 L1 STEC meters of L1 delay 0 10000 20000 230000 40000 50000 680000 70000 s0000 90000 time 5 45000 s0000 55000 bOOOD 565000 tir S B gA G E U P C Tutorial associated to the GNSS Data Processing book 123 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia 1 Select the satellite longitude latitude height coordinates of message OUTPUT in the gLAB out file Generate a file with these coordinates comma separated grep OUTPUT gLAB out gawk BEGIN OFS print 16 15 17 gt track tmp 2 Add the header Prefix kml and the tail Postfix km1 files to the previous track tmp data file cat Prefix kml gt grace track kml cat track tmp gt gt grace track kml
63. esiduals Orbit and Clock comparison Orbit and Clock Source J e Broadcast Precise 1 file Precise 2 files nia Y m Global Graphic Parameters RINEX Navigation File home gLAB brdc1230 00n LT TOT ee s AE Z m Title NEU positioning error X label time s Y label error m Clear Automatic Limits X min X max Y min Y max lonosphere Source if activated SINEX File A Individual Plot s Configuration Vi Show Broadcast same as navigation Broadcast specify home gLAB igs00P1060 snx NEU positioning error SPP Full model Plot Nr 1 Plot Nr T T T examine EE Sree i i East error Source File Mai AB out UP error Dotted Line v Auxiliary Files P1 Cl Correction P1 P2 Correction Show CO Show Condition OUTPUT v X Colum SEC DE error nm Save Config gLAB out 10000 20000 30000 40000 50000 60000 70000 B ODU 90000 tima 5 gAGE UPC Tutorial associated to the GNSS Data Processing book G4 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia NEU Position Error plot from gLAB out gLAB Version 2 0 0 NEU positioning error SPP Full model 150 North error r 3 East error NEU positioning error Horizontal positioning error Ze
64. frequency f where is the number of electrons per area unit I Nd along ray path STEC Slant Total Electron Content ud e Two frequency receivers can remove this error source up to 99 9 using lonosphere tree combination PLU f2L2 of pseudoranges PC or carriers LC LC pa gt 1 2 Single frequency users can remove about a 50 of the ionospheric delay using the Klobuchar model whose parameters are broadcast in the GPS navigation message 1996 1998 2000 2002 2004 2006 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia amp e gA GE U P C ac ku D Tutorial associated to the GNSS Data Processing book 43 Example of model component analysis TROPO The gLAB configuration can be set up as follows to repeat the processing without applying the tropospheric correction but using the ionosphere again gLAB Version 2 0 0 glLAB gAGE UPC os http www gage es Cesa Preferences About Positioning nalysis Modelling Options vj Satellite clock offset correction J Consider satellite movement during signal flight time K Consider Earth rotation during signal flight time Satellite mass center to antenna phase center correction Receiver antenna phase center correction Receiver antenna reference point correction Set again Iono Disable Tropo K lonosphe
65. gLAB out 1000008500 20000 30000 70000 50000 60000 70000 4 80000 90000 400000 200000 0 200000 400000 E East error m i 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s NEU error SPP NO Sat clocks 2nd May 2000 Model Satellite clock offset SPP LAB out BED 200000 necu ME MEE m posee EE Miu Satellite clock offsets 100000 L nde S eee m 1000000 300000 off Zoom North error East error UP error 500000 S A This is the largest error EE Po source and it may FEN oos RN NEMUS N introduce errors up to a ae thousand kilometers oe gLAB1 out a mu 10000 20000 30000 70000 E 60000 70000 80000 90000 300000000 20000 zT 40000 30000 60000 70000 80000 90000 B gA GE U P C Tutorial associated to the GNSS Data Processing book 5 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Exercise 1 SPP Model components analysis Satellite clock offsets They are time offsets between satellite receiver clocks time and GPS system time provided by the ground control segment The receiver clock offset is estimated together with receiver coordinates e Satellite clock offset values are provided In real time within the broadcast navigation message with a few meters of error S A off or In post process mode by IGS precise
66. gage es uu c L i P http www gag esa gLAE O sAGEUP http www gage es Preferences About Preferences About Modelling Outp Positioning Analysis Positioning Analysis l l D Specify Use SINEX station Data GNSS Satellite Selection Modelling Options Precise Products Data Interpolation Examine E M Satellite clock offset correction z M Data Dechnation s 300 a Gp Orbit Interpolation Degree 10 Consider satellite movement during signal flight time p files X m Data decimation 7 i i i i i i Clock interpolation Degree 0 A Satellite Optic 7i Consider Earth rotation during signal flight time J butFiles brdc1230 00n Examine Y m Elevation Ma Mark this option to decimate the input data at the specified rate in seconds If this option is V Satellite mass center to antenna phase center correction Roreb QE Phane Canter ME SERA RESETS Z m apart ge time an Sapia ei y he d sis d T P the ee Wi Receiver antenna phase center correction Specify Read from ANTEX Di piace s option is check a is ec ma and not even mode even in decima T P peo E found Discard Sa data all the epochs are used for cycle slip detection and arc length computations but the process is amp Receiver antenna reference point correction corso Discard un stopped just before the modelling ivicti i ici This option is meant to be used to
67. gnal direction Puch atthe abe soe xS Thence neglecting this For geodetic positioning a on ETE RA correction an error on the raferenes fae to ihe antena 6 X vertical component occurs but iy ES i a xim is 90000 not In the horizontal one ARP or to monument Is used ES amp gA GE U P C Tutorial associated to the GNSS Data Processing book 68 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Exercise 2 PPP Model components analysis Satel I ite Mass Ce nte r to Vertical positioning error Kinem PPP 7 Horizontal positioning error kinem e Full model Antenna Phase Center Satellite t RUPEE eee 1 NY buen ue SI MENT MEC Antenna n ME UNE Se sO NE NE RN Phase Center E oo APC GANE CHE Satellite z Mass gLAB out 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 a 0 3 0 2 21 0 0 0 1 02 0 3 0 4 Center Time og East error m Model Satellite MC to APC offset Kinem PPP Y MC j Satellite MC to APC NENNEN The satellite MC to APC Broad t orbit ZEN eccentricity vector depends on roaaCcast OrbitS are ae ee eee ees ees es en es ee the satellite The APC values referred to the antenna t asd ped used in the IGS orbits and phase center but IGS mmm clocks products are referred to precise orbits are referred c M edi the iono free combination LC to t
68. he satellite mass center MEE NE 0 4 a ale Hi PIT ecu d Eod uc PC They are given in the IGS 0 Ix 3558 3558 us Sos Soo 3355 a 90000 ANTEX files e g 1gs 5 e atx amp gA GE U P C Tutorial associated to the GNSS Data Processing book Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares 69 Technical University of Catalonia Exercise 2 PPP Model components analysis Wind up affects only carrier 2c Vertical positioning error Kinem PPP 2c Horizontal positioning error Kinem PPP phase It is due to the 7 out electromagnetic nature of i ages omeia beh ho circularly polarized Waves of rU NES A TERN OPES NS EL ees See GNSS signals pU MEM MEME MEE ena ee CECI TOET As the satellite moves along its M EES a E orbital path it performs a AMV rotation to keep its solar panels NENNEN pointing to the Sun direction i This rotation causes a carrier variation and thence a range measurement variation Wind Up Wind up changes smoothly DENETOSRUUNS along continuous carrier phase 1 Phase arcs C 2 r variation In the position domain wind up affects both vertical and horizontal components ED ON a Hmm B gA GE U P C Tutorial associated to the GNSS Data Processing book Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia
69. if out file Print FILTER Messages Print OUTPUT Messages to avoid big output files Save Config 1 SPP Template PPP Template how Output z EN 3 Make plots roe EL c as before Run gLAB Om ie ef im ie ie amp gA GE U P C Tutorial associated to the GNSS Data Processing book 87 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 3 Dual freq LC PC carrier and code with precise orbits amp clocks GRACE A Broadcast positioning LCPC Along Track error 0 GRACE A Broadcast positioning LEPC Radial error Questions vol N DS D S A O SO A DO MN 7 Which is the improvement in as L precise orbits and clocks E oo jor accuracy regarding the broadcast case How do carrier phase gt fe oe 00 b dd o Po measurements allow to 0 10000 20000 30000 MEAM 60000 70000 80000 90000 0 10000 20000 30000 uer ae 60000 70000 80000 90000 Improve the accuracy Why do large peaks appear Why does a 40 50 cm bias appear in the radial component Why do wind up and satellite antenna phase center offset corrections have to be applied What about the solid tides correction GRACE A Broadcast positioning LCPC Cross Track error iolisigab Sra pact pore E I Y Radial Along Track Cross Track 55000 60000 65000 time s amp gA GE U P C Tutorial
70. ight May 1t 2000 Day Of Year 123 amp gA GE U P C Tutorial associated to the GNSS Data Processing book 57 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Exercise 2 PPP Model components analysis A Compute the kinematic PPP solution using files ramo1230 000 igs prei1400 atx igs10602 sp3 igs00P1060 snx gLAB Version 2 0 0 Gu Preferences al About Positioning Analysis D gAGE UF gLAB Version 2 0 0 http www gage es Preferences Positioning Analysis ENCCENM E NNCOTI NNN CX NNNETTY A priori receiver position Calculat Specify M Use SINEX File Show ANTEX File home gLAB igs pre1400 atx Orbit and Clock Source Measurements Troposhere 2 Broadcast Precise 1 file Precise 2 files VGA Selection amp Estimate Troposphere SP3 File home gLAB igs10602 sp3 Pei ij F PARAE eee oe er ECEN Available Frequencies lonosphere Source if activated SINEX File Single Frequency 1 Show AB igs00P1060 snx Measurement configuration and noise Dual Frequency PC v Fixed StdDev m 1 O Elevation StdDev m LL 4 Receiver Kinematics aN AI LC v Fixed StdDev m 0 01 Elevation StdDev m uxiliary Files ___ LL P1 C1 Correction P1 P2 Correction Show Show Parameters
71. ile Compute differences with reference file GRAA 07 080 sp3 Make plots as before 1 Convert the output gLAB out file to sp3 format Execute in Console out2sp3 gLAB out orb sp3 2 Compare the computed coordinates orb sp3 with reference GRAA 7 080 sp3 3 Plot dif out file amp gA GE U P C Tutorial associated to the GNSS Data Processing book O6 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Mode 5 Single freq L1 C1 carrier and code with precise orbits amp clocks GRACE A Broadcast positioning P1L1 Radial error GRACE A Broadcast positioning P1L1 Along Track error Lit ud i Py n UE i Questions 15 Explain why the solution 5pm has a more defined pattern with large oscillations No ionospheric corrections have been applied in this run What would happen if the Klobuchar model is applied 55000 bOOO0 65000 time 5 B gA GE U P C Tutorial associated to the GNSS Data Processing book 97 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 5 Single freq L1 C1 carrier and code with precise orbits amp clocks A Answer to Question 15 Explain why the solution has a more defined pattern with large oscillations This effect is due to the error introduced by the ionosphere and the
72. inations i e ionosphere free combinations 4 GRAPHIC combination of C1 code and L1 carrier phase 5 Single frequency C1 code and L1 carrier and no ionospheric corrections A Data files A Measurements file graaQ 800 070 A GPS orbits and clocks A Broadcast brdc0e800 07n A Precise cod14193 sp3 cod14193 clk igs05 1402 atx A GRACE A Precise Reference Orbit file GRAA 07 080 JE o aes GE U P C Tutorial associated to the GNSS Data Processing book 7 4 bch gro up of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Te chnical Un ie of Catalo Mode 1 Single frequency C1 code with broadcast orbits amp clocks Example of computation with gLAB Code positioning broadcast orbits Single frequency C1 code gLAB Version 2 0 0 gLAB Version 2 0 0 Input Files p GNSS Satellite Selection on RINEX Observation File home gLAB graa0800 070 Examine E Data Decimat i GPS C Show ANTEX z Orbit and Clock Source Satelli All None Broadcast Precise 1 file Precise 2 files Eleva egrees 5 RINEX Navigation File ho ga LAB brdc0800 07n Examine Di L Dis i Set calculate EED Select files june C Melbourne W bb amp have a higher number of graa0800 e 070 Set SPP V L1 C1 difference brdc0800 07n 1 output samples Set data decimation to 30 seconds instead of 300 to
73. ion 7 13 Run gLAB Convert the output gLAB out file to sp3 format 4 In console mode Execute in Console Convert the gLAB out to orb sp3 format file http www gage es z O gAGE UPC From previous configuration From previous disable TGD configuration set e P1 P2 Correction Dual Frequency PC Combination Kinematic 2 Compare the computed coordinates orb sp3 with reference GRAA 07 080 sp3 iie 2 the RA l l Compute d ifferences if with reference file 3 Plot dif out file GRAA 07 080 Sp3 amp gA GE U P C Tutorial associated to the GNSS Data Processing book 82 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia Mode 2 Dual frequency PC code with broadcast orbits amp clocks GRACE A Broadcast positioning PC Along Track error Plotting ae a i ba t e Make the same plots as in the previous case meters e Questions 7 4 Why is the solution noisier than the previous one with C1 code Discuss the pros and cons of the ionosphere free combination of codes PC compared with C1 code How could the performance be improved GRACE A Broadcast positioning PC Cross Track error GRACE A Broadcast positioning PC Radial Along Track Cross Track meters ce 0 10000 20000 30000 40000 50000 680000 70000 s0000 90
74. ipath Noise M edes l 10 Model components Prefit residuals Postfit residuals Orbit and Clock comparison EAS ge Carrier Global Graphic Parameters Title Model components X label time s Y label model m Clear 30 advanc v Automatic Limits X min X max Y min Y max 40 i zu 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 Individual Plot s Configuration time s Plot Nr 1 Plot Nr 2 Plot Nr 3 Plot Nr 4 mr lonosphere delays code and Condition MODEL v v 1 MODEL Blue v advances Carrier measurements E ix c ENNB Note Use the gLAB out file ot AR out Tn In gLAB1 out file this model aaa IONO component was switched off amp gA GE U P C Tutorial associated to the GNSS Data Processing book 41 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia error m error mi 150 NEU positioning error SPP Full model 150 North error East error UP error IU Po NE EUNTEM TURNS T Mar PEE i 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s NEU error SPP No lono com 2nd May 2000 North error East error UP error yooL ee a FM soj Ap oe E o
75. ite clock offset correction V Satellite clock offset correction u 5 E B NH GLAB Version 2 0 0 Positioning Analysis vi Consider satellite movement during signal flight time Consider satellite movement during siggal flight time Consider Earth rotation during signal flight time Consider Earth rotation during sig t time Satellite mass center to antenna phase center correction e a u 1 Satellite mass center to antenna phasllenter correction Jj S a e Bi Receiver antenna phase center correction a In Modeling panel oregon Receiver antenna reference point correction Receiver antenna reference point corr lt configuration disable the model sem lonospheric 3 Nominal v Simple Mapping Tropospheric correction UNB 3 Nominal v Simple Mapping v D Pl P2 correction RINEX Nav File Ls O r P p CO Mm D O I e nt tO vi P1 P2 correction RINEX Nav File v de r re ct i O n SES Q 4 K vi P1 Cl correction Flexible v vi P1 Cl correction Flexible v Wind up correction Carrier phase only _ Wind up correction Carrier phase only Solid tides correction l nN l 7 e Solid tides correction Relativistic path range correction E Relativistic path range correction Save Config SPP Template PPP Template Run gLAB n th l S exa m p e d S a b e Save Config SPP Template PPP Template Run gLAB a o gL AB 6 saGEuP lonospheric correction gL
76. ity of Catalonia Example 2 Static Precise Point Positioning PPP PPP Template Static positioning with dual freq code amp carrier ionosphere free combination PC ENT 4 pue processed precise orbits amp clocks 1 Select the PPP Template Cesa m Preferences e EE o 2 Upload data files Measurement roap1810 090o ANTEX igs05 1525 atx Orbits amp clocks igs15382 sp3 e Positioning 9Analysis e Broadcast Precise 1file Precise 2 files SP3 rie Imre Examine SINEX igs09P1538 snx lonosphere Source if activated SINEX File 3 H U N Q Ly B C Show EAB AGSOSP ISSA Auxiliary Files P1 Cl Correction P1 P2 Correc tion o me 3 Default output file em gLAB out GE U P M Tutorial associated to the GNSS Data Processing book 20 ich gro up of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Te chnical Un Mito of Catalo Example 2 Static Precise Point Positioning PPP i SS Plotting Results e Coordinates are taken as 0220 T E 3 1 311 E constants in nav filter all East error mE UP error e Dual frequency Code and NN Carrier measurements Precise orbits and clocks Measurements modelling at the centimetre level NEU positioning error Static PPP error m Centimetre level
77. jares Technical University of Catalonia OVERVIEW Y Introduction Y The gLAB tool suite Y Examples of Positioning with gLAB Y Laboratory session organization LABORATORY Session gt Starting up your laptop Basic Introductory laboratory exercises Ex1 Ex2 A Medium Laboratory Work Project LWP Kinematic positioning of a LEO satellite A Advanced Homework amp gAGE UI C Tutori Research group of Astronomy amp Geomatics J Technical University of Catalonia t Sanz Subi al associated to the GNSS Data Processing book 28 irana J M Juan Zornoza M Hernandez Pajares otarting up your laptop 1 Plug the stick into an USB port and boot your laptop from the stick 2 Access the Boot Device Menu when starting up the laptop Note he way to do it depends on your computer Usually you should press ESC or F4 F10 F12 amp gA GE U P C Tutorial associated to the GNSS Data Processing book 29 Research group of Astronomy amp Geomatics J irana J M Juan Zornoza M He ajares Technical University of Catalonia t Sanz Subira rn ndez P ES The US keyboard is set by default rg You can change it t by clicking on the UE de upper right corner gLAB Manual G T zi N Q 1 mu j M Q h 3 5 3 v eT Ww 30 43 Applications Places System P i Tue jun 21 8 48AM glab Esp m gAGE v z En P um j 4 1 hi ip P E
78. l components Prefit residuals Orbit and Gock comparison Global Graphic Parameters Title Vertical positioning error X Iabel time 5 Ylabel err bal Graphic Parameters Automatic Limits Jemin eee marten Ymin J0 4 Title Vertical positioning error X label time 5 Individual Plot s Configuration Automatic Limits X min X max Plot Nr 1 Plot Nr 2 Plot Nr 3 Individual Plot s Configuration E e Plot Nr 1 Plot Nr 3 Plot Nr 4 C v ts1 ouTPUT Examine Dotted Ling v x coum DSTAU Blue y Label Full Model Plot amp gA GE U P C Tutorial associated to the GNSS Data Processing book 65 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Horizontal Position Error plot gLAB out gLAB1 out gLAB Version 2 0 0 gLAB NUT Kinem PPP gLAB Version 7 0 0 2c Horizontal positioning error No Solid Tides corr e eFull model Cosa esa Positioning Analysis Positioning Analysis Preferences Templates d NEU positioning error Horizontal positioning error Zenith Troposphe Templates NEU positioning lonospheric combinations Dilution Of Precision Satellite skyplot Carrier phase am Dilution Of Pre Meagur Multipath N rse Model components Prefit residuals Postfit residi Model components Preht resyuiials Postnt residuals Orbit and Sock comparison Global Graphic Parameters
79. le Plot the P2 code noise and multipath for time interval 43000 67000 Show in the same graph 1 ALL satellites 2 PRN16 and 3 PRN21 see Plot HW3 c graph py f P2 txt x2 y3 s cl y l ALL f P2 txt c 1 16 x2 y3 so cl r 1 PRN16 f P2 txt c 1 21 x2 y3 so cl g 1 PRN21 xn 43000 xx 67000 yn 8 yx 28 amp gA GE U P C ac ku Tutorial associated to the GNSS Data Processing book 113 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia HW3 Code measurements noise assessment C1 P1 P2 and PC D The next commands compute the PC combination noise and multipath 1 Using the meas txt file generated before with the MEAS message data format Id YY Doy sec GPS PRN el Az N list C1C L1C C1P L1P C2P L2P 12 3 4 5 6 x x 9 10 11 xx 13 14 15 16 Ah Ah _Y5 RB f y l Compute PC noise and multipath as omn Ahh Ah yh h y 1 gawk BEGIN g 77 60 2 print 6 4 g 13 14 15 16 g 1 meas txt gt PC txt 2 From previous PC txt file Plot the PC combination noise and multipath for time interval 43000 67000 Show in the same graph 1 ALL satellites 2 PRN16 and 3 PRN21 see Plot HW3 d graph py f PC txt x2 y3 s cl y 1 ALL f PC txt c 1 16 x2 y3 so cl r 1 PRN16 f PC txt c 1 21 x2 y3 so cl g 1 PRN21 xn 43000 xx 67000 yn 8 yx 28
80. leseBl l 2 2 2l2222 222lL l l ll222senl eco qe an nnnnnn Sennen Deere Orne rene l0 i f 10 oe ee ee ee DEEI F4 gt MM AI R B SL B oben HEAT Lese LLLI n o a 2 Er ETA vP E cR c RM UR DECUS NTC 5 90000 10 0 10 20 30 40 East error m Earth rotation during signal flight time 20000 30000 40000 60000 70000 80000 18000 50000 Model Earth rotation during signal flight time SPP Notice the clear eastward shift when neglecting this term of the model 50000 60000 70000 80000 90000 time s 20000 30000 40000 10000 9 gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Tutorial associated to the GNSS Data Processing book J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Basic Introductory laboratory exercises Exercise 2 Model components analysis for PPP his exercise is devoted to analyze the additional model components used in Precise Point Positioning the ones which are not required by SPP This is done in Range and Position Domains Because PPP uses precise orbits and clocks the positioning accuracy is not affected by the selective availability as with broadcast orbits and clocks and thence no distinction will be done with S A on or S A off Note Selective Availability S A was an intentional degradation of public GPS signals implemented for US national security reasons S A was turned off at midn
81. mt 7 j i Dilution Of Pre Meagur Multipath Noise Model components Prefit residuals Postfit residu S P AM c p N l Model components Prefit reg uals Postfit residuals Orbit and Crack comparison Global Graphic Parameters Title Horizontal positioning err X label East error m Y label No Global Graphic Parameters Y min 20 Title Horizontal positioning err el East error m Y label Ni aerror m Plot Nr 3 v 1 OUTPUT amp 4 gt 15 Ee pom DSTAN vs Blue v Label Full Model 4 gt 1 5000 Plot To plot from 12515000 sec when S A off amp e gA GE U P C Tutorial associated to the GNSS Data Processing book 40 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia lonospheric model component plot gLAB out gLAB Version 2 0 0 http www gage es Hgure T Model components Cesa 30 Preferences About eomm l l 20 Positioning Analysis Templates 10 NEU positioning error Horizontal positioning error Zenith Tropospheric Delay lonospheric combinations E _ 24 E 3 0 Dilution Of Precision Satellite skyplot Carrier phase ambiguities Measur Mult
82. n LT Save Config SPP Template PPP Template Run gLAB g GLAB Version 2 0 0 Nr Cesa gLAB e secure http www gage es Preferences About Positioning Analysis Output Dg Output Fil gLAB out Examine Messages vi Print INFO Messages auci MSN In the Default V Print INPUT Messages _ Print MEAS Message ees configuration the Print EPOCHSAT Messages a Print PREFIT Messages t t f Print POSTFIT Messages O u p u e Was v Print FILTER Messages PRU gLAB out Save Config SPP Template PPP Template Run gLAB 9 Ru iS gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia gLAB Version 2 0 0 Proceed as In the _ gLAB previous exercise 77 LI 1 n M O d e n a e Modelling Options Precise Products Data Interpolation p Satellite clock offset correction Orbit Interpolation Degree 10 disable th del er antenna Phase tente Correction i t t Relativistic clock correction orbit excentricity _ lonospheric correction a a a a YZ e v Tropospheric correction Simple Nomina v Niell Mapping O I I es E 2 Save as gLAB1 out the associated output file v eter http www gage es Consider satellite movement during signal flight time t time Clock interpolation Degree 0 Consider Earth rotation during sig i v v Satellite mass center to antenna pha Vi Receiver antenna ph
83. nith Tropospheric Delay lonospheric combinations UP error r T 100 3 Dilutiin Of PreWsion Satellite skyplot Carrier phase ambiguities Measur Multipath Noise Mogel componen Prefit residuals Postfit residuals Orbit and Clock comparison Global Graphic Parameters Title IN positioning error X label time s Y label error m Clear E v Autoflnatic Limits X min X max Y min Y max O 0 adiuiduE Diciis Configuratigg ET 5 50 Source File gLAB out e Examine Dotted Line v Condition OUTPUT v 1 OUTPUT Blue v TID A00 p RIEeEeeHnee K Cony SEC iv 4 Y Column DSTAN v 18 Label North error 3 EMEN 150 Plot 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 time s 9 gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Tutorial associated to the GNSS Data Processing book 35 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Exercise 1 SPP Model components analysis ee enn The different model g LAE 9 sacEuPc components will be analyzed Ec Eum http www gage es with gLAB Preferences Preferences About Analysis e Using the previous data file the impact of neglecting each model The modeling component will be evaluat
84. odel components Prefit residuals Postfit residuals Orbit and Clock comparison wes PIOT 3 Global Graphic Parameters Title lonospheric combinations X Jabel time s Y abel STEC L1 12 delay m Clear m Templates Automatic Limits X min 43000 X max 67000 Y min 10 Y max 10 individual Plot s Configuration rae 2 7 Pa 2 4 z 2 z 2 RES Mura MATES UE NEU positioning error Horizontal positioning error Zenith Tropospheric Delay lonospheric combinations Source File gLAB out Examine Dots C os Condition pur Y v s1 INPUT Blue Dilution Of Precision Satellite skyplot Carrier phase ambiguities Measur Multipath Noise X Column AI PRN L1 L2 Model components Postfit residuals Prefit residuals Orbit and Clock comparison Global Graphic Parameters Title llonospheric combinations X label time s STEC L1 L2 delay m O Automatic Limits X min 43000 Xemax 67000 Individual Plot s Co zenith Tropospheric Delay lonospheric combinations Positioning Templates NEU p Diluti 2 Carrier phase ambiguities Measur Multipath Noise Q Plot Nr 1 CO Plot Nr 2 O Plot Nr 4 Model components Prefit residuals Postfit residuals Orbit and Clock comparison 50 urce File gLAB out Examine Circles Global Graphic Parameters Title lonospheric combinations X abel time
85. of measurements ionosphere troposphere relativity etc This is done both in the Signal In Space SIS and User Domains oasses the modelling needs in terms of the GPS positioning service accuracy the impact of neglecting each model component will be evaluated in a S A on off scenario Note Selective Availability S A was an intentional degradation of public GPS signals implemented for US national security reasons S A was turned off at May 2 2000 Day Of Year 123 amp gA GE U P C Tutorial associated to the GNSS Data Processing book 33 Researc h eh d Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares echnical University of Catalo Exercise 1 SPP Model components analysis 1 Compute SPP using files ramo1230 000 brdc1230 00n igs00P1060 snx gLAB Version 2 0 0 Cesa GLAB 8 0000o Preferences 8 e o o P Preferences About Positionigg Analysis e NEU positioning error orizont itioning error Zenith Tropospheric Delay lonospheric combinations e Po onina SAna EEEE E E NNNNCTRNNNN ome A priori receiver position O Calculate RINEX Observation File home gLAB ramo1230 000 2s Dilution Of Precision Sate skyplot Carrier phase ambiguities Measur Multipath Noise Use SINEX File Hen C Show ANTEX m Model components Prefit residuals Postfit r
86. on StdDev m 6 Qq Parameters Phi Q Po Other options Coordinat 0 les m les m C Backward filtering i x i Receiver Clock o 9e10 m 9e10 ne Troposphere 1 1e 4 mz h 0 25 m me de ue Decimetre error level UU ET Sa navigation after the best Receiver navigated as a rover _ part of an hour 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 in a pure kinematic mode time 5 B gA GE U P C Tutorial associated to the GNSS Data Processing book 22 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia OVERVIEW v Introduction v The gLAB tool suite Y Examples of GNSS Positioning using gLAB Laboratory session organization LABORATORY Session A Starting up your laptop Basic Introductory laboratory exercises Ex1 Ex2 A Medium Laboratory Work Project LWP Kinematic positioning of a LEO satellite A Advanced Homework gAGE UPC Research group of Astronomy amp Geomatics J Technical University of Catalonia rial associated to the GNSS Data Processing book 23 irana J M Juan Zornoza M Her ajares t Sanz Subira nandez P Laboratory session organization A The laboratory session is organized as an assisted activity were a set of exercises must be developed individually or in groups of two A As they are con
87. onfiguration of exercise 1 activate the lonospheric Correction option in the Modelling panel and run again gLAB The program will output the file gLAB out see help and file format executing gLAB linux messages or gLAB linux help 2 grep the MODEL messages of file gLAB out selecting the C1P PRN time Klob iono data grep MODEL gLAB out grep C1P gawk print 6 4 25 3 gt klob txt Note the Klob data is shifted by 3 meters to align the curves in the plot 3 Plot in the same graph the ionospheric delays of satellites PRN16 and PRN21 from I1 txt and klob txt file see Plot HW1 c in the previous slide Note Both the Graphic User Interface GUI panel or the graph py tool in console mode can be used for plotting gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia aC ku Tutorial associated to the GNSS Data Processing book 108 D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares HW2 Plot in the same graph the True 3D error the Formal 3D error and the number of satellites used Analyze the result A Complete the following steps 1 Configure gLAB as in Mode7 and set Print EPOCHSAT Messages in Output panel see message content in the Tooltip or executing gLAB linux messages Hemember that IONO corrections were unable in Mode 1 2 Run gLAB The program will output the file gLAB out 3 Generate
88. onfigure and use Templates and carefully chosen defaults e Able to be executed in command line and to be included in batch processing File Edit View Terminal Help g4 workspace edunav gLAB linux input obs test madr2000 060 input sp3 test igsl3843 sp 3 input ant test igsO5 atx amp gA GE U P C Tutorial associated to the GNSS Data Processing book 9 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Technical University of Catalonia The gLAB Tool suite A n order to broad the tool availability gLAB software has been designed to work in both Windows and Linux environments ae A A The package contains ay e Windows binaries with an installable file e Linux tgz file e Source code to compile it in both Linux and Windows OS under an Apache 2 0 license Example data files e Software User Manual HTML files describing the standard formats amp gA GE U P C Tutorial associated to the GNSS Data Processing book 10 Research group of Astronomy amp Geomatics J irana J M Juan Zornoza M He ajares Technical University of Catalonia t Sanz Subira rn ndez P The gLAB Tool suite A Read files capability RINEX observation v2 11 amp v3 00 RINEX navigation message SP3 precise satellite clocks and orbits files ANTEX Antenna information files Constellation status DCBs files GPS_Receiver_Type files
89. ook ich gro up of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Te chnical Un Mito of Catalo Mode 1 Single frequency C1 code with broadcast orbits amp clocks gLAB Version 2 0 0 Preferences C Positioning e Analysis e Set plotting ranges http www gage es About Temone a Xmin Xmax Ymin Ymax NEU positioning error Horizontal positioning erro a 7 a combinations 1 Dilution Of Precision Dilution Of Precision Satellite skyplot Satellite skyplot Carrier phase apibiquities Measur Multipath Noise Mode components Model components Prefit residuals Prefit residuals refit residuals Postfit gesiduals p Orbit and Clock Orbit and clock comparison Global Graphic Parameters Title Broadcast positioning C1 X abel time s label error m Clear Automatic Limits X min 43000 X max 67000 Y min 20 Individual Plot s Cormmgurauorr O Plot Nr 1 O Plot Nr 3 Source File dif out Condition SATDIFF SATDIFF v T x iv XColumn sec RE Swgolumn CROSS TRACK v CO Plot Nr 4 os MN Examine Dots v eo doses zi Br ies x in 15 Label Cross Track 4 SS 20 Hgure T mana GRACE A Broadcast positioning C1 Radial Along Cross error m o
90. p www gage es Output Destination Output File gLAB out e vi bun INFO Messages Print CS Cycle Slip Message Print INPUT Messages Print MEAS Message Print MODEL Messages Print EPOCHSAT Messages Print PREFIT Messages Print POSTFIT Messages Print FILTER Messages E EXHI DEL INL T EET DEL INI Print OUTPUT Messages Save Config gLAB Version 2 0 0 Examine Disable all messages except Print INFO Messages Print OUTPUT Messages tQ avold big c PML 3 sw Output Run gLAB Tutorial associated to the GNSS Data Processing book J Sanz Subirana J M Juan Zornoza M Hernandez Pajares 76 Mode 1 Single frequency C1 code with broadcast orbits amp clocks Accuracy assessment of the computed solution Complete the following steps to compare the output solution from gLAB out file with the reference coordinates of file GRAA 07 080 sp3 1 Convert the output gLAB out file to sp3 format Execute in Console out2sp3 gLAB out gLAB out gt NE Note this sentence generates the file Es see file content with less orb sp3 2 Compare the computed coordinates orb sp3 with reference GRAA 07 080 sp3 Note Use the configuration file dif cfg Note this sentence generates the file 3 Plot dif out file The Graphic User Interface can be used for plotting Q aes GE U P C Tutorial associated to the GNSS Data Processing b
91. r than the previous one with LC PC Unlike the previous case where carrier phase data with few millimetres of error were provided now the most accurate measure provided to the filter is the GRAPHIC combination with tens of centimetres of error A Answer to Question 14 Let s see the next two exercises amp gA GE U P C ac ku Tutorial associated to the GNSS Data Processing book O4 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 5 Single freq L1 C1 carrier and code with precise orbits amp clocks Example of computation with gLAB Code and Carrier precise orbits amp clocks Single frequency L1 C1 From previous configuration EE complete the following steps esa gLAE Input Upload the brdc0800 07n file preferences Me in the P1 P2 correction 2 Model Set P1 P2 correction select RINEX Navigation File as DCB source C JARUMA ome gLAB graa0800 070 Examine Saa X xs big br od http www gage es Rae GLAB igsO5 1402 atx Examine Preferences About X m Positioning ANglysis file Preci files sAGEU http www gage es Positioning Analysis c3 Lo A priori receiver position z Vimi me gLAB cod14193 sp Examine t N naana ell fee me gLAB cod14193 clk Examine
92. rack error GRACE A Broadcast positioning GRAPHIC 4 i i i 1 r i Radial Along Track Cross Track 13 Why is the solution noisier than the previous one with LC PC Would the performance be improved directly using the L1 P1 measurements like in the LC PC case 10000 20000 30000 40000 50000 680000 70000 0000 SO0OO00 time 5 B gA GE U P C Tutorial associated to the GNSS Data Processing book O3 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia Mode 4 Single freq with L1 C1 GRAPHIC comb and precise orbits amp clocks A Answer to Question 12 Which is the main benefit of the GRAPHIC combination The GRAPHIC combination is defined as G P L e Thence since the ionospheric refraction has opposite sign in code P and carrier L GRAPHIC removes the ionospheric error e On the other hand the code noise is reduced by a factor 2 i e 0 1 20 e However this is an ambiguous measurement due to the unknown carrier phase bias e Note Due to the gLAB filter design a code measurement must also be provided to the filter along with the GRAPHIC one Nevertheless a large sigma noise is set to this code in order to downweight this measurement in the filter in this way the solution will be driven by the GRAPHIC combination A Answer to Question 13 Why is the solution noisie
93. ric correction Klobuchar Tropospheric correction OOO K Seo P1 P2 correction RINEX Nav File v Flexible lv Wind up correction Carrier phase only P1 Cl correction Solid tides correction Relativistic path range correction Save Config SPP Template PPP Template Run gLAB e Positioning nalysis e gLAB Version 2 0 0 Preferences Output Destigememm Output File Messages Print INFO Messages i Print CS Cycle Slip Message K Print INPUT Messages Print MEAS Message Print MODEL Messages E AB e O U Print EPOCHSAT Messages Print PREFIT Messages hf fA x D Print POSTFIT Messages as output file Print FILTER Messages S Print OUTPUT Messages Save Config SPP Template PPP Template e The same scheme must be applied for all other model terms TGDs relat gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Tutorial associated to the GNSS Data Processing book J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares 44 Exercise 1 SPP Model components analysis NEU positioning error SPP Full model Vertical positioning error SPP Horizontal ch tla error SPP D o North error e eNO Tropo corr East error o Full model j UP error UJ o 20 F m 10 P PME E M dS ack
94. rnoza M Hernandez Pajares Mode 3 Dual freq LC PC carrier and code with precise orbits amp clocks Example of computation with gLAB Code amp Carrier precise orbits amp clocks Dual frequency LC PC gLAB Version 2 0 0 gLAB gLAB Version 2 0 0 gLAB A gAGE UPC http www gage es http www gage es Cesa fesa Preferences About i Preferences Positioning Analysis Positioning Analysis Modelling Options Precise Products Data Interpolation Measurements Satellite clock offset correction About pi Disable Estimate Pseudorange Carrier p Orbit Interpolation Degree 10 Consider satellite movement during signal flight time Consider Earth rotation during signal flight time Clock Interpolation Degree o Satellite mass center to antenna phase center correction Receiver antenna phase center dir F P P P fi d m bl E Receiver antenna reference poi d ro m CO n g u rat O n 5 sa e m Receiver Antenna Phase Center amp SI XN K Troposphere phe teas amp Dual Frequency Measurement configuration PC v Fixed StdDev m 1 Elevation StdDev m E z AX LIS aJ t EL s u n e o A no o m A et o i4 et b Lc v Fixed StdDev m 0 01 Elevation StdDev m lonospheric correction e Receiver Antenn
95. ross track position difference meters gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia aC ku Tutorial associated to the GNSS Data Processing book 116 D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares HW4 Broadcast orbits and clocks accuracy assessment using the IGS precise products as the accurate reference i e the truth lt lt GFS ECOBACIS Frocise UGS APGI Raciti anor GPS Broadcast Precise s le APC Along Track error R M HH Comments e Meter level errors are found on broadcast orbits and clocks aa re i Ee Si a ee E The bias seen in the radial component is RN us Mages ted m m us id un due to the different APC s used by the n IDEE GPS ground segment i e in broadcast orbits and by IGS precise products e This bias is compensated by a similar ZEE UA ee EL shift in clocks 0 10000 20000 30000 40000 50000 60000 70000 80000 9000 0 19000 30000 30000 40000 50000 60000 70000 80000 90000 me time s e For the Signal In Space Range Error GPS Broadcast Precise IGS APC Cross Track eerror SISRE please see the plot below GPS Broadcast Precise IGS APC Clock error x idm ii iti SUT Ha rail x i nid a e iit M Lr tl i GPS Broadcast Precise IGS APC SISRE ily n Mart a h gall Wann 2 EC ips i ig iit utt iti il Sis ta je csi im ii ud us i i i Ur ane i5 i ii x i tes du gr lij A E T m
96. s Technical University of Catalonia HW4 Broadcast orbits and clocks accuracy assessment using the IGS precise products as the accurate reference i e the truth Complete the following steps File brdce800 07n contains the orbit and clocks data broadcast in the GPS navigation message Files cod14193 sp3 cod14193 clk contain the precise orbits and clocks computed in post process by CODE center IGS precise orbits and clocks products program 1 Execute the following sentence to compute the difference of satellite coordinates and clock offsets between both orbits and clocks sources gLAB linux input nav brdc06800 07n input SP3 cod14193 sp3 input ant igs05 1402 atx gt dif tmp 2 Select the SATDIFF message of dif tmp file 1 SATDIFF grep SATDIFF dif tmp dif out 2 Year 3 Doy Days of Year SATDIFF message content is shown in the table beside 4 Seconds of day seconds see gLAB_linux messages 5 GNSS System GPS GAL GLO or GEO 6 PRN satellite identifier The IGS post processed products are accurate at few cm level thence they can be taken as the truth 7 SISRE difference meters 8 SISRE orbit only difference meters 3 Plot dif out file as in the first exercise 9 3D orbit difference meters 10 clkDif f Clock difference meters gt 11 radDif f Radial position difference meters Note SISRE J ARad ACIK D AAlon ACross 12 atDiff Along track position difference meters 13 ctDiff C
97. s Y label STEC L1 L2 delay m Clear Condition f Automatic Limits X min 43000 X max 67000 Y min 10 Y max 10 i Individual Plot s Configuration Plot Nr 1 Plot Nr 2 Plot Nr 3 Plot Nr 4 X C j olumn SEC Source File gias out Examine Dots v Condition INPUT v PRN 16 vy 1 INPUT amp 6 16 Green v X Column Y Column ma Label m P2 P1 Plot gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia Tutorial associated to the GNSS Data Processing book 104 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares HW1 Assessing the ionospheric delay on the GRACE A satellite Plot HW1 a Comments 1m 55 m e ALL L1 L2 l l i diac a dps e 2 The ionospheric delay STEC computed from L1 L2 aligned carriers is shown in blue for all satellites e The red circles show the L1 L2 delay for sat PRN16 e he green circles show the ionospheric delay on PRN16 computed from P2 P1 code measurements As it is shown in the plot the STEC variations are typically at the meter level but in some cases they increase up to several meters The code measurement noise and multipath in the P2 P1 MM combination is typically at the meter level but in the ends of aol cL i data arcs low elevation rays can reach up to a few meters 45000 50000 55000 60000 65000 time s STEC meters of L1 L2 delay The previous
98. search group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia Mode 3 Dual freq LC PC carrier and code with precise orbits amp clocks A Answer to Question 9 Why do large peaks appear e The peaks are related to massive cycle slips experienced after each revolution about 1 5 h e After a cycle slip happens the filter has to restart the carrier ambiguity This is not a problem when it occurs on a single satellite being the others well determined as its ambiguity is estimated quickly But when a massive cycle slip occurs the filter needs more time to converge see HW5 Answer to Question 10 Why does a 40 50 cm bias appear in the radial component e This is the GRACE A antenna phase centre offset Please notice that we are positioning the Antenna Phase Centre APC while the coordinates in the SP3 reference file GRAA 07 080 sp3 are referred to the satellite Mass Centre MC Homework HW5 Analyze the carrier phase biases convergence in this kinematic PPP positioning gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia aC ku Tutorial associated to the GNSS Data Processing book 90 D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Mode 3 Dual freq LC PC carrier and code with precise orbits amp clocks A Answer to Question 11 Why do wind up and GPS satellite antenna phase center
99. t if they were oy A OE cw wss not considered the station Tv oe eel coordinates would oscillate with oo relation to a mean value They produce vertical mainly and horizontal displacements meters ro o ul amp gA GE U P C Tutorial associated to the GNSS Data Processing book 6 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia PPP Model Components Analysis Vertical positioning error Kinem PPP Horizontal positioning error Kinem PPP Receiver Antenna Phase center APC a SLABT QUT ne receiver arc conection 0 1 OR fr vcccccccccenescccscanencncnnecasenesemeccassnceceus cesencscasemcccsscanesemsnecace sessmeccace cesses L2 Antenna Phase center E 5 L1 Antenna Phase center 9 o0 E ool m Aa ns a t 5 E Antenna Reference Point ARP oat ME E TEN m E aab ee gLAB out gL 0 45 10000 20000 30000 40000 50000 60000 70000 80000 90000 Oba 03 202 n E 0 1 0 2 0 3 0 4 G NSS measu rements are Model Receiveir APC to ARP offset Kinem PPP referred to the APC This is not Poe ee ed Receiver APC necessarily the geometric _ J SRE eil vets The antenna used for this center of the antenna and It OEE Wi ree experiment has the APC depends on the signal popni eee n qvo position vertically shifted frequency and the incoming M MEO x X aS E iu regarding ARP radio si
100. the broadcast i cg isl eli pst oas xu OR 2 Orbits and clocks are accurate at posse ap iet Ite e et at e ME Hint i few meters level see plots at left fn fn oe eee IGS precise orbits amp clocks are 0 D 6605 3x00 W565 sha 60000 mios 80000 90000 0 m 55655 35050 40000 Saba 60000 39308 80000 90000 accu rate at few cm level time s time s meters gAGE UPC Research group of Astronomy amp Geomatics Technical University of Catalonia aC ku Tutorial associated to the GNSS Data Processing book 62 D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Solid Tides model component plot gLAB out esa Preferences Positioning pree NEU positioning error Horizontal positioning error Dilution Of Precision Satellite skyplot Prefit residuals Model components Templates Global Graphic Parameters Title Model components x label time 5 Automatic Limits X min X max Individual Plotis Configuration e Plot Nr 1 Plot Nr 2 source HIE gLAB out Condition MODEL Jen i T 1 gLAB Version 2 0 0 gLAB About Zenith Tropospheric Delay lonaspheric combinations Carrier phase ambiguities Measur Multipath Noise Postfit residuals Orbit and Clock comparison label model mj Clear Tun TMAx Plot Nr 3 Plot Nr 4 Examine Dots Aur as MODEL Blue ia X Column Y Colum SOLIDTIDES 28 gAGE UPC Research group
101. the dif out file from gLAB out as in the previous exercises Plot the results In the same graph plot the SD error from file dif out the formal error the 3 D sigma and the number of satellites used in the computation from file gLAB out graph py f dif out x4 y9 s l 3D error f gLAB out c 1 OUTPUT x4 y 5 5 s cl r 1 5 sigma f gLAB out c 1 EPOCHSAT x4 y6 s cl g 1 N sat used xn 43000 xx 67000 yn yx 20 Note 3D sigma o PDOP In the previous plot the 3 D sigma is multiplied by 5 to enlarge the image amp gA GE U P C ac ku Tutorial associated to the GNSS Data Processing book 109 Research group of Astronomy amp Geomatics D J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares Technical University of Catalonia HW2 Plot in the same graph the True 3D error the Formal 3D error and the number of satellites used Analyze the result LL 3D error 3D formal error N satellites used 06 10000 20000 30000 40000 50000 60000 70000 80000 90000 Plot HW2 a Periodic error peaks appear mostly associated with losing a satellite and or with bad m 20 3D error 3D formal error N satellites used 45000 50000 55000 60000 Plot HW2 b Zoom of Plot HW2 a Along the peaks associated to bad geometries mismodelling is also producing some error trends 0 dics up o of As
102. tioning modes are analyzed and different modeling options will be discussed http www gage es E Preferences Static ssion 5b Ex7a GRACE A Precise positioning PPP Cross Track Given that session time is limited to 3h students who feel comfortable using gLAB can skip part of the previous basic exercises Ex1 Ex2 and jump to the Lab Work Project B gA GE U P C Tutorial associated to the GNSS Data Processing book 26 J Sanz Subirana J M Juan Zornoza M Hernandez Pajares Research group of Astronomy amp Geomatics Technical University of Catalonia Laboratory session organization A 3 Advanced Labeled as Homework exercises A set of additional exercises addressed to those students that already have a solid background on GPS data processing These exercises are out of the scope of this 3h laboratory session and are posed for a possible further discussion As in the previous cases the answers to the posed questions are also included as BACKUP slides lonos pheric delay ALL Li L e PRN16 P2 P1 e ePRNI6LI L2 A minimum knowledge of UNIX e g awk is required for these homework exercises gawk BEGIN g 77 60 2 print 6 4 g 13 14 15 16 g 1 meas txt gt PC txt amp gA GE U P C Tutorial associated to the GNSS Data Processing book 27 Research group of Astronomy amp Geomatics J Sanz Subirana J M Juan Zornoza M Hern ndez Pa
103. tool suite Source code and binary software files plus configuration files allowing processing GNSS data from standard formats The options are fully configurable through a GUI e gAGE GLUE Bootable USB stick with a full environment ready to use based on LINUX Ubuntu OS amp gA GE U P C Tutorial associated to the GNSS Data Processing book Researc h group of Astronomy amp Geomatics Technical University of Catalonia OVERVIEW Y Introduction v The gLAB tool suite Examples of GNSS Positioning using gLAB Laboratory session organization LABORATORY Session A Starting up your laptop Basic Introductory laboratory exercises Ex1 Ex2 A Medium Laboratory Work Project LWP Kinematic positioning of a LEO satellite A Advanced Homework amp gAGE UI C Tutori Research group of Astronomy amp Geomatics J Technical University of Catalonia t Sanz Subira al associated to the GNSS Data Processing book 14 irana J M Juan Zornoza M Her ajares nandez P Basic Introductory Lab Exercises A Standard and Precise Point Positioning To Illustrate how easy to process GNSS data using gLAB a GPS receiver will be positioned in the next examples using Example 1 Broadcast orbits and clocks SPP kinematic Example 2 Precise Orbits and clocks PPP static Example 3 Precise Orbits and clocks PPP kinematic e Solutions will be compared with an accurate reference value of receiver
104. tro lee s chnical University of Catalon Tutorial associated to the GNSS Data Processing book 110 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares HW3 Code measurements noise assessment C1 P1 P2 and PC A The next commands compute the C1 code noise and multipath 1 Using the configuration file meas cfg READ the RINEX and generate the MEAS message with data format Id YY Doy sec GPS PRN el Az N list CiC L1C C1P L1P C2P L2P 12 3 4 5 6 x x 9 10 11 Xxx 13 14 15 16 Execute gLAB linux input cfg meas cfg input obs graa0800 070 gt meas txt 2 From meas txt file Compute C1 code noise and multipath as M Cci Li Y 1 L2 s gawk BEGIN g 77 60 2 print 6 4 11 14 2 14 16 g 1 meas txt gt C1 txt 3 From C1 txt file Plot the C1 code noise and multipath for time interval 43000 67000 Show in the same graph 1 ALL satellites 2 PRN16 and 3 PRN21 see Plot HW3 a graph py f C1 txt x2 y3 s cl y 1 ALL f C1 txt c 1 16 x2 y3 so cl r 1 PRN16 f C1 txt c 1 21 x2 y3 so cl g 1 PRN21 xn 43000 xx 67000 yn 8 yx 28 J Sanz Subirana J M Juan Zornoza M Hern ndez Pajares amp gA GE U P C a C ku p Tutorial associated to the GNSS Data Processing book 111 Research group of Astronomy amp Geomatics Technical University of Catalonia HW3 Code measurements noise assessment C1 P1 P2 and PC a B The next commands compute the P1 code

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