Rinex Observation File

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

Rinex Observation File

See Also