Rinex Observation File

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The RinexObsFile object provides functionalities for reading and writing Global Navigation Satellite System (GNSS) Observation data to and from a Rinex Observation file. This is an ASCII file of Pseudorange data conforming to the RINEX standard. The time system is GPS Time, and the scalar data is reference frame independent. FreeFlyer supports the RINEX 2 and RINEX 3 formats.

 

For information on how to simulate GNSS Pseudorange data, see Simulating Tracking Data.

For information on how to generate RINEX Observation files, see Generating Tracking Data Files.

For information on viewing and editing data in a RINEX Observation file, see Using the Tracking Data Editor.

For information on including a RINEX Observation file in a Kalman Filter, Unscented Kalman Filter, or Batch Least Squares OD process, see Including Tracking Data in an Estimation Process.

 

More information on the RINEX format can be found in several locations. Two example references are provided below:

 

http://en.wikipedia.org/wiki/RINEX

https://files.igs.org/pub/data/format/rinex305.pdf

 

Occasionally, GNSS Observation data is provided either in receiver dependent formats, or in a "compact" RINEX format, known as the Hatanaka format. Several conversion utilities are freely available from:

 

http://facility.unavco.org/software/preprocessing/preprocessing.html

ftp://terras.gsi.go.jp/software/RNXCMP/

 

Examples of the format of a RINEX Observation file (version 2 and 3) are given below. The header includes information on:

 

The RINEX version and type

The program used to create the data

The types of observations

The time of the first observation

 

After the header, data is divided into sections, grouping measurements taken at the same time together. Multiple measurements may exist for the same epoch due to visibility to multiple GPS satellites. The lines indicating the date include this information:

 

Year

Month

Day

Hour

Minute

Second

Epoch Flag record

o0 is "OK - No events occurred"

oValues greater than 0 indicate that an event occurred. See the links above for more details.

Number of visible satellites

Identifiers for each of the visible satellites

 

After the line indicating the date, the columns contain measurement data. The data types for each column are indicated in the header.  For RINEX 3, the three-character codes are used to indicate the following:

 

Measurement Type

oC - Code phase

oL - Carrier phase

oD - Doppler

oS - Signal strength

Frequency Band

o1-9

Channel or Code

oC, S, L, X, Y, M, etc.

 

The RINEX 2 format only supports GPS, while the RINEX 3 format supports GPS, Galileo, and other navigation constellations. All GPS measurements supported in RINEX 2 are also supported in RINEX 3. Possible data types include:

 

RINEX 2 (GPS-specific)

oL1

oL2

oC1

oC2

oP1

oP2

oD1

oD2

oS1

oS2

 

RINEX 3

oSee https://files.igs.org/pub/data/format/rinex305.pdf for a complete list of available measurement codes. Codes available for pseudorange measurement processing in FreeFlyer are listed explicitly below.

oGPS Measurements

C1C (analagous to C1 in RINEX 2)

C1S

C1L

C1X

C1P (analagous to P1 in RINEX 2)

C1W

C1Y

C1M

C2C (analagous to C2 in RINEX 2)

C2D

C2S

C2L

C2X

C2P (analagous to P2 in RINEX 2)

C2W

C2Y

C2M

C5I

C5Q

C5X

oGalileo Measurements

C1A

C1B

C1C

C1X

C1Z

C5I

C5Q

C5X

C7I

C7Q

C7X

C8I

C8Q

C8X

C6A

C6B

C6C

C6X

C6Z

 

Note: FreeFlyer GNSS Pseudorange Observations may include the IonoFree Measurement type; these measurements will not be written out to file.

 

Example of RINEX 2 format:

 

    2.11           Observation         G (GPS)             RINEX VERSION / TYPE

FreeFlyer           a.i. solutions      10/15/2009 13:51:08 PGM / RUN BY / DATE

                                                           MARKER NAME

FFUser              FFUser                                  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    C2    P1    P2                              # / TYPES OF OBSERV

 2008     8     1     0     0   14.0000000     GPS         TIME OF FIRST OBS

                                                           END OF HEADER

08  8  1  0  0 14.0000000  0 12G02G05G09G10G12G14G15G17G18G21G22G24

 27631235.834    27631243.638    27631240.407    27631238.556

 21554346.831    21554345.592    21554349.678    21554343.778

 19705383.109    19705378.674    19705378.907    19705383.851

 23810273.723    23810272.598    23810274.460    23810272.339

 20832107.402    20832108.345    20832108.947    20832109.194

 26706262.088    26706267.362    26706265.857    26706264.032

 21706635.676    21706639.615    21706635.472    21706638.599

 26927865.582    26927861.555    26927865.088    26927862.736

 21332010.175    21332007.546    21332011.420    21332013.064

 21945748.253    21945747.413    21945747.187    21945750.275

 24989459.233    24989463.784    24989465.153    24989464.876

 22466862.899    22466865.674    22466864.390    22466869.601

08  8  1  0  1 14.0000000  0 12G02G05G09G10G12G14G15G17G18G21G22G24

 27349445.598    27349442.529    27349444.455    27349444.389

 21185626.298    21185628.067    21185625.698    21185628.085

 19908226.323    19908226.149    19908229.845    19908227.433

 23595344.595    23595341.681    23595346.339    23595344.018

 20569038.482    20569040.772    20569039.637    20569039.265

 26729250.934    26729256.391    26729253.928    26729256.519

 22006588.736    22006590.705    22006588.537    22006591.155

 27140103.999    27140104.351    27140103.547    27140104.300

 21533528.397    21533533.464    21533528.199    21533528.571

 21801380.286    21801379.149    21801378.752    21801380.684

 25234406.846    25234406.775    25234405.367    25234406.548

 22117960.210    22117961.476    22117960.454    22117961.037

 

Example of RINEX 3 format:

 

    3.03           OBSERVATION DATA    G (GPS)             RINEX VERSION / TYPE

FreeFlyer           a.i. solutions      20211208 194359 UTC PGM / RUN BY / DATE

MARKER                                                      MARKER NAME

FFUser              FFUser                                  OBSERVER / AGENCY

RECNUM              RECTYPE             RECVERS             REC # / TYPE / VERS

ANTNUM              ANTTYPE                                 ANT # / TYPE

       0.0000        0.0000        0.0000                  APPROX POSITION XYZ

       0.0000        0.0000        0.0000                  ANTENNA: DELTA H/E/N

E    3 C7X C8X C1B                                          SYS / # / OBS TYPES

G    3 C1C C2X C5X                                          SYS / # / OBS TYPES

    5.000                                                  INTERVAL

 2020     3    11     0     0    0.0000000     GPS         TIME OF FIRST OBS

                                                           END OF HEADER

> 2020 03 11 00 00 23.0000000  0 12    

G10  21174855.31600  21174854.83900  21174865.47100

G12  21949684.39800  21949682.03100  21949691.20300

G15  23628922.50700  23628912.13100  23628913.32500

G20  19532355.26300  19532344.60900  19532340.10300

G21  22136216.92700  22136216.73800  22136217.06400

G25  19768344.04900  19768343.48300  19768346.87400

G26  24384546.18700  24384550.17900  24384549.59000

G29  22584553.10600  22584549.22400  22584549.84500

G31  23629075.68700  23629093.20500  23629079.84800

E02  23653041.41000  23653035.12700  23653033.45500

E03  24214020.95200  24214024.45800  24214018.26500

E30  22335059.88500  22335050.14000  22335048.26800

> 2020 03 11 00 00 28.0000000  0 12    

G10  21158898.29300  21158897.30100  21158912.26100

G12  21912028.04800  21912037.57300  21912026.70800

G15  23610807.52600  23610823.60400  23610826.17600

G20  19537523.49800  19537524.38000  19537530.20400

G21  22179809.44200  22179810.43800  22179814.97300

G25  19753589.50200  19753584.40400  19753595.16600

G26  24428448.98200  24428444.37900  24428439.12700

G29  22603638.53500  22603633.81500  22603630.82700

G31  23651451.97000  23651476.75200  23651463.76500

E02  23629476.96100  23629464.23300  23629478.56100

E03  24182415.56400  24182403.68400  24182409.69100

E30  22354805.70900  22354789.31400  22354801.91300

 

 

See Also


RinexObsFile Properties and Methods