International GNSS Service (IGS) analysis centers provide clock solutions to NASA’s Crustal Dynamics Data Information System (CDDIS) using pre-determined schedules, e.g., daily and weekly. The IGS analysis center coordinator retrieves these solutions and produces a combined product, which is then in turn archived at CDDIS. The IGS produces clock results in two forms, tabulated at 5 minutes and 30 seconds. These combination solutions are considered the official IGS products.

IGS clock combination solutions are available in two forms: rapid and final. The rapid clock combination is a daily solution available approximately 17 hours after the end of the previous UTC day. The final, and most consistent and highest quality IGS solutions, consists of daily clock files, generated on a weekly basis approximately 13 days after the end of the solution week. All clock solution files utilize the RINEX Extensions to Handle Clock Information.

All operational IGS GNSS products (i.e., orbits, station positions, EOP, clock solutions) are available in subdirectories by GPS week. Solution summary files are provided by the analysis centers in which they describe their analysis methods and strategies and list processing statistics. IGS provides descriptions of AC analysis procedures and models used.

In 2009, 2013, and 2020 the IGS initiated “reprocessing campaigns” (repro1, repro2, and repro3 respectively). The IGS analysis centers re-processed the GNSS data from the global network of IGS stations (from 1994 to 2007 for repro1, from 1994 through 2012/2013 for repro2, from 1994 through 2022 for repro3) to produce a fully consistent set of products utilizing the most recent models and updated processing strategies. These reprocessed solutions are available within the weekly subdirectory structure as outlined below, in /repro1, /repro2, and /repro3 and subdirectories.

The starting directory for these files (GPS and GPS+GLONASS solutions) is:

and for GLONASS-only solutions:

At the end of 2022, the IGS made the decision to change the name format going forward of many of its products archived at CDDIS. A table is available on the IGS website which compares the old and new name formats. The table can be found on the following page:

Name Format Since GPS Week 2238

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

WWWW/AAA0PPPTYP_YYYYDDDHHMM_LEN_SMP_CNT.FMT.gz

as described in the table below.

Name Format Before GPS Week 2237

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

WWWW/AAAWWWWD.TYP.Z

as described in the table below.

Though many clock products are available, the products listed below have permanent DOIs: