High-rate (Sub-hourly) data

The CDDIS archive contains GNSS data from the global network of permanent GNSS receivers operating at a higher, 1-second sampling rate. These data are submitted and archived in files containing 15 minutes of data. IGS analysis centers retrieve these sub-hourly data files to produce IGS near real-time and "ultra-rapid" products such as satellite ephemerides, clocks, and Earth rotation parameters.

IGS stations forward the sub-hourly 1-second GNSS data in compressed RINEX format to the CDDIS within minutes following the end of the 15-minute time block. At the present time, sub-daily data from 285 high-rate sites are archived each day. Each site ideally submits 4 observation files/hour or 96 observation files/day requiring approximately 25GB/day or 9.1TB/year in storage. Many sites also submit broadcast ephemeris files (for multi-GNSS sites) and some provide meteorological data. Many of the sites are real-time, streaming sites whose data are captured and translated into blocks of 15-minutes of RINEX data. High-rate GNSS data available in RINEX V2 format use the mmmmDDDHMM.YYt.gz filename convention and are in gzip compressed format. Starting with data from 2016, all high-rate GNSS data in RINEX V3 that uses the RINEX V3 filenaming convention and the gzip compression format are archived in the /gnss/data/highrate area with the RINEX V2 data files.

Beginning June 15, 2022, CDDIS will only maintain individual high-rate files for the most current six months. After 6 months all files will be consolidated into tar files. See the section on highrate tar consolidation.

The starting directory for these sub-hourly, high-rate individual files is:

Append the following directory and file names to the starting directory using the format codes in the links below:

YYYY/DDD/YYt/HH/mmmmDDDHMM.YYt.gz

RINEX V2 format
View format codes

YYYY/DDD/YYt/HH/XXXXMRCCC_K_YYYYDDDHHMM_15M_01S_tt.FFF.gz

RINEX V3 format
View format codes



Tar Process for GNSS Sub-hourly High-rate Files

Beginning June 15, 2022: All high-rate data files will be merged into a single tar archive file by site and by data type. This consolidation will simplify the directory structure and simplify the download process for users. Each data type (e.g., observation, navigation, etc.) will be contained in a separate tar archive.

The creation of these tar files will start with the oldest data (2001) and move forward. Current data for a six month period will remain archived using the present structure (i.e., by day of year, hour, and file type). Once individual 15-minute files are merged into a site/type/day tar file, the individual 15 minute files will be removed and archived off-line.

Before being merged into tar files, all Unix compressed RINEX V2 data with file extension ".Z" will be switched to gzip compression with the file extension ".gz". This change in compression is in accordance with the IGS transition to gzip conversion for RINEX V2 data after December 1, 2020.

The starting directory for the tar files is:

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

Append the following directory and file names to the starting directory using the format codes in the links below:

YYYY/DDD/mmmmDDD0.YYt.tar

RINEX V2 format
View format codes

YYYY/DDD/XXXXMRCCC_K_YYYYDDD0000_01D_01S_tt.FFF.tar

RINEX V3 format
View format codes