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I'm currently trying to process some data from a uBlox receiver in RAWX format to calculate precise positions using only GLONASS data. Using the latest version of RTKLib I have successfully created a .obs file for the rover data which contains only raw timing data from GLONASS satellites.

I am using base station observation data from the Ordnance Survey which contains GLONASS observations. However, I can't seem to find ephemeris data for GLONASS satellites in RINEX .n files.

I downloaded ephemeris data from http://cddis.gsfc.nasa.gov/Data_and_Derived_Products/GNSS/broadcast_ephemeris_data.html but this doesn't seem to work, when I run rnx2rtkp with ephemeris data from here combined with my rover and base station data the result is a file with headers but no calculated positions.

Is there a reliable source for GLONASS ephemeris data? Or do you think the problem with empty files after running rnx2rtkp lies somewhere else?

Sample of rover .obs file used:

         2.11           OBSERVATION DATA    M (MIXED)           RINEX VERSION / TYPE
CONVBIN 2.4.2                           20151103 124700 UTC PGM / RUN BY / DATE 
log: ./example-raw-files/move_8t_open_2.ubx                 COMMENT             
format: u-blox                                              COMMENT             
                                                            MARKER NAME         
                                                            MARKER NUMBER       
                                                            OBSERVER / AGENCY   
                                                            REC # / TYPE / VERS 
                                                            ANT # / TYPE        
        0.0000        0.0000        0.0000                  APPROX POSITION XYZ 
        0.0000        0.0000        0.0000                  ANTENNA: DELTA H/E/N
     1     1                                                WAVELENGTH FACT L1/2
     4    C1    L1    C2    L2                              # / TYPES OF OBSERV 
  2015    10    18    14    29   57.0001660     GPS         TIME OF FIRST OBS   
  2015    10    18    14    31   48.0001660     GPS         TIME OF LAST OBS    
                                                            END OF HEADER       
 15 10 18 14 29 57.0001660  0  7R 2R18R 1R24R 3R10R 9
  19056340.595   101688288.003                                  
  20456342.222   109197298.083                                  
  21472771.747   114784298.522                                  
  22602776.418   120867227.872                                  
  21531288.261   115258699.757                                  
  23149996.728                                                  
  24006237.266   128191924.241                                  
 15 10 18 14 29 58.0001660  0  7R 2R18R 1R24R 3R10R 9
  19056198.116   101687528.005                                  
  20455687.529   109193802.134                                  
  21473303.889   114787143.115                                  
  22603448.334   120870822.141                                  
  21530504.061                                                  
  23149729.173                                                  
  24006561.864   128193661.999                                  
 15 10 18 14 29 59.0001660  0  7R 2R18R 1R24R 3R10R 9
  19056055.746   101686766.803                                  
  20455032.245   109190304.363                                  
  21473836.223   114789986.801                                  
  22604120.342   120874416.557                                  
  21529722.719   115250328.3173                                 
  23149464.647   123399672.5182                                 
  24006892.415   128195398.326                                  
 15 10 18 14 30  0.0001660  0  7R 2R18R 1R24R 3R10R 9
  19055913.199   101686007.061                                  
  20454376.416   109186808.225                                  
  21474368.852   114792830.975                                  
  22604792.481   120878010.252                                  
  21528935.003   115246142.6322                                 
  23149200.632   123398265.7823                                 
  24007214.118   128197136.108   

Sample of Base station .obs file used:

     2.11           OBSERVATION DATA    M (MIXED)           RINEX VERSION / TYPE
teqc  2013Mar15                         20151018 16:08:01UTCPGM / RUN BY / DATE
Linux2.6.32-279.el6.x86_64|x86_64|gcc|Win64-MinGW64|=       COMMENT
TPP 3.8.0                               18-OCT-15 13:59     COMMENT
The APPROX POSITION XYZ coordinates are NOT APPROXIMATE     COMMENT
APPROX POSITION XYZ replaced with ETRS89 station coords     COMMENT
                                                            COMMENT
STRA                                                        MARKER NAME
Stratford                                                   MARKER NUMBER
OS Net              Ordnance Survey                         OBSERVER / AGENCY
5302K56524          TRIMBLE NETR9       5.01                REC # / TYPE / VERS
30436573            TRM55971.00     NONE                    ANT # / TYPE
  3974813.0408      661.0574  4971513.6274                  APPROX POSITION XYZ
        0.0000        0.0000        0.0000                  ANTENNA: DELTA H/E/N
     1     1                                                WAVELENGTH FACT L1/2
    14    C1    P1    L1    D1    S1    C2    P2    L2    D2# / TYPES OF OBSERV
          S2    C5    L5    D5    S5                        # / TYPES OF OBSERV
    30.0000                                                 INTERVAL
     0                                                      RCV CLOCK OFFS APPL
    17                                                      LEAP SECONDS
Forced Modulo Decimation to 30 seconds                      COMMENT
  2015    10    18    14     0    0.0000000     GPS         TIME OF FIRST OBS
                                                            END OF HEADER
 15 10 18 14  0  0.0000000  0 19G01G03G04G08G11G14G17G19G23G28G31G32
                                R01R02R03R09R10R18R24
  20180757.438                   106050661.061 7                        49.700
                  20180764.938    82636982.767 9                        43.200
  20180763.324    79193776.328 9                        54.700
  20828922.820                   109456879.989 7                        47.300
                  20828929.609    85291188.678 8                        40.400
  20828930.973    81737408.712 9                        53.700
  20984973.547                   110276794.074 7                        49.200
                  20984978.281    85930067.781 8                        38.800

  23759403.547                   124856355.955 6                        42.400
                  23759413.504    97290747.902 6                        23.000
  23759413.980    93236966.578 9                        44.900
  20463251.977                   107535262.028 7                        50.800
                  20463256.078    83793693.296 8                        40.000

  23581631.273                   123922415.590 5                        40.500
                  23581637.781    96562996.519 6                        22.600

  23028052.273                   121013265.584 6                        45.900
                  23028058.363    94296074.902 8                        34.500

  21221326.406                   111518773.953 7                        48.600
                  21221330.051    86897841.898 8                        40.200

  24670831.742                   129646153.107 5                        40.900
                  24670839.879   101023039.675 6                        21.700

  23654508.750                   124305349.413 6                        43.800
                  23654514.102    96861295.041 6                        25.300

  25302107.750                   132963469.966 3                        35.200


  20224880.313                   106282567.307 7                        49.400
                  20224885.035    82817687.926 8                        40.100

  20471495.016    20471493.355   109432451.662 8                        51.000
  20471499.797    20471500.152    85113834.399 8                        40.600

  19388043.594    19388042.391   103458712.558 8                        51.700
  19388047.516    19388047.449    80467801.253 9                        47.300

  22901519.039    22901518.742   122594071.205 6                        42.300
  22901528.422    22901527.504    95350710.061 8                        40.000

  23493632.766    23493631.383   125454651.909 6                        41.500
  23493637.723

  23723380.070    23723378.582   126458813.713 5                        39.700
  23723388.762    23723387.586    98357002.949 8                        33.800

  21638628.500    21638627.305   115508486.132 7                        48.300
  21638633.754    21638634.063    89839936.201 9                        43.300

  21344462.984    21344461.762   114138445.687 5                        41.000
  21344469.105    21344468.637    88774370.937 8                        39.300

 15 10 18 14  0 30.0000000  0 19G01G03G04G08G11G14G17G19G23G28G31G32
                                R01R02R03R09R10R18R24
  20182485.414                   106059740.872 7                        49.100
                  20182492.691    82644057.945 9                        43.500
  20182491.426    79200556.710 9                        54.800
  20818845.320                   109403922.438 7                        47.800

Example ephemeris data from http://cddis.gsfc.nasa.gov/Data_and_Derived_Products/GNSS/broadcast_ephemeris_data.html :

         2              NAVIGATION DATA                         RINEX VERSION / TYPE
CCRINEXN V1.6.0 UX  CDDIS               19-OCT-15 17:31     PGM / RUN BY / DATE 
IGS BROADCAST EPHEMERIS FILE                                COMMENT             
    0.1583D-07  0.0000D+00 -0.1192D-06  0.0000D+00          ION ALPHA           
    0.1106D+06  0.0000D+00 -0.2621D+06  0.6554D+05          ION BETA            
   -0.186264514923D-08-0.710542735760D-14   147456     1867 DELTA-UTC: A0,A1,T,W
    17                                                      LEAP SECONDS        
                                                            END OF HEADER       
 1 15 10 18  0  0  0.0 0.258162617683D-05 0.795807864051D-12 0.000000000000D+00
    0.830000000000D+02 0.312500000000D+01 0.469305261319D-08 0.283487930010D+00
    0.210478901863D-06 0.475879025180D-02 0.712089240551D-05 0.515365367127D+04
    0.000000000000D+00 0.707805156708D-07 0.172698137717D+01 0.558793544769D-07
    0.962625218850D+00 0.244968750000D+03 0.491006304726D+00-0.811319544880D-08
    0.360372148789D-09 0.100000000000D+01 0.186700000000D+04 0.000000000000D+00
    0.200000000000D+01 0.000000000000D+00 0.512227416039D-08 0.830000000000D+02
    0.000000000000D+00 0.000000000000D+00 0.000000000000D+00 0.000000000000D+00
 2 15 10 18  0  0  0.0 0.593069475144D-03 0.125055521494D-11 0.000000000000D+00
    0.320000000000D+02 0.170312500000D+02 0.522414600468D-08 0.864108924348D+00
    0.817701220512D-06 0.148657076061D-01 0.710412859917D-05 0.515364379501D+04
    0.000000000000D+00-0.225380063057D-06 0.168627558652D+01 0.931322574615D-07
    0.941300472669D+00 0.233062500000D+03-0.222396368177D+01-0.857642845631D-08
    0.228938104585D-09 0.100000000000D+01 0.186700000000D+04 0.000000000000D+00
    0.200000000000D+01 0.000000000000D+00-0.204890966415D-07 0.320000000000D+02
    0.000000000000D+00 0.000000000000D+00 0.000000000000D+00 0.000000000000D+00
 3 15 10 18  0  0  0.0 0.196569599211D-04-0.159161572810D-11 0.000000000000D+00
    0.330000000000D+02-0.159062500000D+02 0.488806062293D-08 0.250572505977D+01
   -0.774860382080D-06 0.479422858916D-03 0.726245343685D-05 0.515357558060D+04
    0.000000000000D+00-0.260770320892D-07 0.276796515213D+01-0.186264514923D-08
    0.959536023018D+00 0.240750000000D+03-0.278869512117D+01-0.813998202176D-08
   -0.213223161349D-09 0.100000000000D+01 0.186700000000D+04 0.000000000000D+00
    0.200000000000D+01 0.000000000000D+00 0.186264514923D-08 0.330000000000D+02
    0.000000000000D+00 0.000000000000D+00 0.000000000000D+00 0.000000000000D+00
 4 15 10 18  0  0  0.0-0.337180681527D-04-0.511590769747D-11 0.000000000000D+00
    0.940000000000D+02 0.721875000000D+01 0.524878984720D-08 0.903745526686D-01
    0.325962901115D-06 0.119663784280D-01 0.713206827640D-05 0.515363929558D+04
    0.000000000000D+00-0.931322574615D-07 0.170137330633D+01 0.147148966789D-06
    0.940394961488D+00 0.235625000000D+03 0.111195399936D+01-0.852785486671D-08
    0.370015407203D-09 0.100000000000D+01 0.186700000000D+04 0.000000000000D+00
    0.200000000000D+01 0.000000000000D+00-0.651925802231D-08 0.940000000000D+02
    0.000000000000D+00 0.000000000000D+00 0.000000000000D+00 0.000000000000D+00
 5 15 10 18  0  0  0.0-0.184040516615D-03 0.386535248253D-11 0.000000000000D+00
    0.620000000000D+02-0.204062500000D+02 0.510628428429D-08-0.297571076922D+01
   -0.107660889625D-05 0.447066326160D-02 0.761076807976D-05 0.515366045570D+04
    0.000000000000D+00-0.912696123123D-07 0.275904508375D+01-0.782310962677D-07
    0.946689739988D+00 0.228156250000D+03 0.444670396318D+00-0.819534129448D-08
   -0.270368394340D-09 0.100000000000D+01 0.186700000000D+04 0.000000000000D+00
    0.200000000000D+01 0.000000000000D+00-0.107102096081D-07 0.620000000000D+02
    0.000000000000D+00 0.000000000000D+00 0.000000000000D+00 0.000000000000D+00
0

So it turns out I misinterpreted the ephemeris file I was using. According to the RINEX standard, GLONASS ephemeris files are denoted .[yy]g, thus, as I was using a .[yy]n, this contained GPS ephemeris data not GLONASS.

My mistake was in thinking .n was the standard extension for ephemeris data for any GNSS, not exclusively GPS.

GLONASS ephemeris data is easily available from NASA in the /[yy]g subdirectory for any given day e.g ftp://cddis.gsfc.nasa.gov/gnss/data/daily/2015/317/15g/

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