RINEX
RINEX (Receiver Independent Exchange Format) is a standardized file format used to store raw data from GNSS such as Galileo, GPS, BeiDou, EGNOS, WAAS, and many others. This format allows for the exchange and processing of GNSS data independent of the receiver manufacturer, facilitating post-processing to achieve higher accuracy in positioning.
RINEX content and structure
The RINEX format comprises three types of ASCII files:
- Observation Data Files store GNSS observations, including carrier-phase measurements, pseudorange (code) measurements, Doppler measurements, and signal-to-noise ratio (SNR) readings. These files facilitate the exchange of raw GNSS data for precise positioning and analysis.
- Navigation Message Files contain broadcast navigation data records, providing essential satellite ephemeris, clock corrections, and other parameters necessary for positioning and timing calculations.
- Meteorological Data Files record meteorological observations collected at GNSS stations, such as atmospheric pressure, temperature, and humidity. These measurements help refine atmospheric models and improve GNSS accuracy.
Each RINEX file is composed of a header and a data section. The header is located at the beginning of the file and contains global metadata applicable to the entire dataset. It does not have a fixed length, allowing flexibility in the information included.
The format is optimized for minimal storage requirements, regardless of the number of observation types supported by a specific receiver or satellite system. This efficiency is achieved by specifying, within the header, the types of observations recorded during the session and the satellite systems observed.
Additionally, there is no maximum record length limitation for observation records, ensuring compatibility with diverse GNSS configurations and data structures.
RINEX evolution
RINEX format has evolved over the years to reflect the advancements in GNSS technology and the need for a flexible, comprehensive data exchange format to support diverse applications in geodesy, surveying, positioning, navigation and timing, among many others.
| Supported Satellite Systems | File Naming Conventions | Observation Codes | Header Information | Data Record Structure | |
| RINEX 2 | Primarily designed for GPS data | An 8.3 filename structure: [SSSS][DOY][f] .[YY][t] | Limited set of observation codes, mainly for GPS signals | Contained basic metadata about the observation session | Simpler data record structure suitable for the GNSS technology of its time |
| RINEX 3 | Extended to multiple GNSS including GLONASS, Galileo and BeiDou | Introduced longer filenames to provide more descriptive information about the data contained within the files | Expanded observation code list to accommodate various signals from multiple GNSS constellations | Enhanced header records to include more detailed information, such as antenna details, receiver types, and more precise time references | Revised the data record structure to handle the increased complexity of modern GNSS signals and observations |
| RINEX 4 | Further enhancements to accommodate new GNSS signals and systems | Introduced longer filenames to provide more descriptive information about the data contained within the files | Continued expansion, adding support for new signal types and improving the clarity and organization of observation codes | Enhanced header records to include more detailed information, such as antenna details, receiver types, and more precise time references | Further refined the data structures to improve data integrity and processing efficiency |
External references
For detailed specifications and guidelines, refer to the official RINEX documentation provided by the International GNSS Service (IGS):