A large percentage of the Global Navigation Satellite System (GNSS) sites provide broadcast navigation data in addition to observation data. NASA's Crustal Dynamics Data Information System (CDDIS) creates daily broadcast ephemeris files from these site-specific files transmitted by the stations; these files (one for GPS, a second for GLONASS) contain the unique GPS or GLONASS satellite ephemeris messages for each day. A similar file is created at the start of the UTC day and updated on an hourly basis from the hourly broadcast navigation files. Users can therefore download a single file each day or hour, which contains all broadcast ephemeris messages required for post-processing.

Daily RINEX V2 GPS Broadcast Ephemeris Files

The daily GPS broadcast ephemeris file is a merge of the individual site RINEX V2 navigation files into one, non-redundant file that can be utilized by users instead of the many individual navigation files.

The starting directory for the daily files is:

Append the following directory and file names to the starting directory (Note, for data created before December 1, 2020, the files are Unix compressed with extension .Z):

YYYY/DDD/YYn/brdcDDD0.YYn.gz (merged GPS broadcast ephemeris file)

or

YYYY/brdc/brdcDDD0.YYn.gz  (merged GPS broadcast ephemeris file)

as described in the table at the bottom of the page.

Hourly RINEX V2 GPS Broadcast Ephemeris Files

The combined broadcast ephemeris file is generated on an hourly basis from all hourly RINEX V2 navigation files archived at CDDIS. The hourly navigation file contains all broadcast messages with the TOE of the day that are available when the file is created at the top of the hour. The file is updated each hour with new navigation messages.

At the end of the UTC day, when the final version of the file is generated, the file is copied to the daily directories and becomes the "daily" broadcast ephemeris file

The starting directory for the hourly files is

Append the following directory and file names to the starting directory (Note, for data created before December 1, 2020, the files are Unix compressed with extension .Z):

YYYY/DDD/hourDDDm.YYn.gz

as described in the table at the bottom of the page.

Daily RINEX V2 GLONASS Broadcast Ephemeris Files

The daily GLONASS-only broadcast ephemeris file can be found in the GNSS navigation file subdirectory.

The starting directory for the daily GLONASS-only files is

https://cddis.nasa.gov/archive/gnss/data/daily/.

Append the following directory and file names to the starting directory (Note, for data created before December 1, 2020, the files are Unix compressed with extension .Z):

YYYY/DDD/YYg/brdcDDD0.YYg.gz

or

YYYY/brdc/brdcDDD0.YYg.gz

Hourly RINEX V2 GLONASS Broadcast Ephemeris Files

The combined broadcast ephemeris file is generated on an hourly basis from all hourly RINEX V2 navigation files archived at CDDIS. The hourly navigation file contains all broadcast messages with the TOE of the day that are available when the file is created at the top of the hour. The file is updated each hour with new navigation messages.

At the end of the UTC day, when the final version of the file is generated, the file is copied to the daily directories and becomes the "daily" broadcast ephemeris file.

The starting directory for the hourly files is:

https://cddis.nasa.gov/archive/gnss/data/hourly/

Append the following directory and file names to the starting directory (Note, for data created before December 1, 2020, the files are Unix compressed with extension .Z):

YYYY/DDD/hourDDDm.YYg.gz

as described in the table at the bottom of the page.

Daily RINEX V3 GNSS Broadcast Ephemeris Files

The daily RINEX V3 GNSS broadcast ephemeris file is a merging of the individual mixed navigation files. This file is updated several times throughout the day as more input files become available.

The starting directory for the daily files is:

https://cddis.nasa.gov/archive/gnss/data/daily/

Append the following directory and file names to the starting directory:

YYYY/DDD/YYp/BRDC00IGS_R_YYYYDDDHHMM_01D_MN.rnx.gz

or

YYYY/brdc/BRDC00IGS_R_YYYYDDDHHMM_01D_MN.rnx.gz

Daily RINEX V4 GNSS Broadcast Ephemeris Files

In late 2021, the RINEX V 4.00 format, which follows the V3 "long" file name specification, was officially accepted by the IGS Governing Board. At the beginning of 2022, colleagues at the Technical University in Munich (TUM) and Deutsches Zentrum für Luft- und Raumfahrt (DLR) began providing to CDDIS a daily broadcast ephemeris file in the RINEX V4 format.

The starting directory for the daily files is:

https://cddis.nasa.gov/archive/gnss/data/daily/

Append the following directory and file names to the starting directory:

YYYY/brdc/BRD400DLR_S_YYYYDDDHHMM_01D_MN.rnx.gz

or

YYYY/DDD/YYp/BRD400DLR_S_YYYYDDDHHMM_01D_MN.rnx.gz

Daily Multi-GNSS Broadcast Ephemeris Files

The TUM/DLR team also provides to CDDIS a merged, multi-GNSS broadcast ephemeris file containing GPS, GLONASS, Galileo, BeiDou, QZSS, and SBAS ephemerides. The file is generated from real-time streams and contains all unique broadcast navigation messages for the day.

Append the following directory and file names to the starting directory:

YYYY/brdc/BRDM00DLR_S_YYYYDDDHHMM_01D_MN.rnx.gz

or

YYYY/DDD/YYp/BRDM00DLR_S_YYYYDDDHHMM_01D_MN.rnx.gz

The daily multi-GNSS broadcast ephemeris files were previously also archived in short filename format through the summer of 2020. These files were stored in the MGEX campaign subdirectories at this starting directory:

https://cddis.nasa.gov/archive/gnss/data/campaign/mgex/daily/rinex3/

Append the following directory and filenames to the starting directory:

YYYY/brdm/brdmDDD0.YYp.Z

Daily Merged GPS/QZSS LNAV and CNAV Navigation Files

These files were also provided by the TUM/DLR team and generated from real-time streams. Archival of these files ceased at the end of 2021.

Append the following directory and file names to the starting directory:

YYYY/brdc/BRDX00DLR_S_YYYYDDDHHMM_01D_MN.rnx.gz

These files were also generated in short filename format and were stored under the MGEX campaign subdirectories. Archival of these files ended in the summer of 2020.

The starting directory for these files is:

https://cddis.nasa.gov/archive/gnss/data/campaign/mgex/daily/rinex3/

Append the following directory and file names to the starting directory:

YYYY/cnav/brdxDDD0.YYx.Z

Data Code Table

The following codes are used in the paths and file names for the data.