GNSS Format Descriptions
Motivation
GNSS data sets follow a well defined set of standards. These standard formats provide many advantages, the most obvious being it is easy to exchange. ASCII and binary formats both satisfy this function, but ASCII does it with greater generality because binary formats are computer operating system dependent. These formats have evolved to satisfy growing requirements, satellite systems, capabilities, etc.
But reading a standard format description is a tough task. This section aims to provide the community a reliable and powerful tool which explains these necessary standards in a very easy and friendly way, aided with explanatory tooltips. These tooltips will be triggered automatically when the mouse is hovered over a field. These explanations include the standard description of the field, the format in which is written and, if applicable, its units.
Get familiar with the different format standard(s) involved in the GNSS data sets, take your time to analyse in detail particularities and characteristics of the GNSS systems, observables, versions, models through the different data sets provided. Please email any suggestions, comments or requests to us.
gFD Quiz
New to GNSS field? How much do you master the different GNSS standards? Do you think you know all the particularities of your daily used format standard? Discover it through the GNSS Format Descriptions (gFD) Quiz prepared by gAGE. The proposed Quiz is based on the explained GNSS formats gathered here. There are no complicated questions to answer, the test guides your mouse through the different formats involved. Click here to take the gFD Quiz now!
This quiz is based on the work of Adria Rovira-Garcia. The gFD Quiz is intentend to be used worldwide: not only by student of professionals starting in the GNSS field, but also to senior researches that need to refresh their knowledge on some particular standard, or need to move to a new format.
Explained Formats
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About the Data
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RINEX FILENAMES DESCRIPTION (from v3.02 onwards)
Field |
Field Description |
Example |
Required? |
Comment/Example |
---|---|---|---|---|
<SITE/ STATION- MONUMENT/ RECEIVER/ COUNTRY or REGION> |
XXXXMRCCC Where: XXXX - 4 character site designation M – monument or marker number (0-9) R – receiver number (0-9) CCC – ISO Country or Region code (Total 9 characters) |
ALGO00CAN | Yes | File name supports a maximum of 10 monuments at the same station and a maximum of 10 receivers per monument. Country or Region code to follow: ISO 3166-1 alpha-3 |
<DATA SOURCE> | Data Source R – From Receiver data using vendor or other software S – From data Stream (RTCM or other) U – Unknown (1 character) |
R | Yes | This field is used to indicate how the data was collected either from the receiver at the station or from a data stream |
<START TIME> | YYYYDDDHHMM YYYY – Gregorian year 4 digits, DDD – day of Year, HHMM – hours and minutes of day (11 characters) |
2012150 1200 |
Yes | For GPS files use: GPS Year, day of year, hour of day, minute of day (see text below for details) Start time should be the nominal start time of the first observation. GLONASS, Galileo, BeiDou, etc use respective system time. |
<FILE PERIOD> | DDU DD – file period U – units of file period. File period is used to specify intended collection period of the file. |
15M | Yes | File Period 15M–15 Minutes 01H–1 Hour 01D–1 Day 01Y–1 Year 00U-Unspecified |
<DATA FREQ> |
DDU DD – data frequency |
05Z | Mandatory for RINEX Obs. Data. NOT required for Navigation Files. |
XXC – 100 Hertz XXZ – Hertz, XXS – Seconds, XXM – Minutes, XXH – Hours, XXD – Days XXU – Unspecified |
<DATA TYPE > |
DD (2 characters) |
MO | Yes |
Two characters represent the data |
<FORMAT> |
FFF (3 characters) |
rnx | Yes | Three characters indicating the data format: rnx - RINEX file crx - Hatanaka Compressed RINEX file |
<COMPRESSION> | 34 or 35 | gz, bz2, zip | No | Suggested to use gzip, but other options are of course bzip2 and zip , for example. |
Sub Total | 34 or 35 | |||
Separators | (7 characters –Obs. File) (6 characters –Nav. File) |
underscore between all fields and “.” Between data type and file format and the compression method |
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Total | 41-42(Obs. File) 37-38 (Nav. File) |
Mandatory IGS RINEX obs. Characters |
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