On 31 October 2020, anonymous ftp access will officially be discontinued at CDDIS. Beginning August 10, 2020, CDDIS will bandwidth limit ALL IPs using anonymous ftp to just 250KB/s transfer rates. CDDIS is STRONGLY recommending all users begin to transition to using alternate method of access to the CDDIS archive. Examples of alternate methods can be found at: https://cddis.nasa.gov/Data_and_Derived_Products/CDDIS_Archive_Access.html.

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Real-time products

The CDDIS provides access to products generated from real-time data streams in support of the IGS Real-Time Service. Two types of products are archived, igt and igc.

The igt solution is a batch combination based on daily clock and sp3 submissions by IGS real-time analysis center. These clock products have been provided since February 2009, shortly after real-time streams were routinely available through the IGS Real-Time Pilot Project and prior to the availability of real-time product streams.

The igc solution is one of the RTS solutions generated by decoding the real-time product streams. The igc files are derived from the IGC01 solution, which uses the real-time data streams that are referred to the satellite center-of-mass (CoM).

  • orbit files (igcWWWWD.sp3.Z) contain the decoded orbit and clock results from the IGC01 real time stream at 30 second intervals
  • clock solution files (igcWWWWD.clk.Z) consist of decoded clock results from the IGC01 real time stream at 30 second intervals
  • solution summary files (ritWWWWD.sum.Z) consist of orbit and clock comparisons of all the AC and combination streams against IGS rapid solution

The CDDIS also provides real-time streaming corrections through its real-time caster. A description of these solutions is available from the IGS RTS website product page.

The starting directory for these files is:

Anonymous ftp service will be discontinued on October 31, 2020.

Append the following file names to the starting directory:


as described in the table below.

Code Meaning
SSSsolution type (igc, igt, or rit=comparison summary)
  • Global Navigation Satellite System (GNSS) Orbit and Clock Comparison Summary for the IGS AC and Combination Real-Time Products with the IGS Rapid Products from NASA CDDIS
    doi: 10.5067/GNSS/GNSS_IGSRTCSUM_001
Dday of week (0-6, 7 indicates weekly)
TYP type of solution (clk=clock correction, sp3=orbit, or sum=solution summary)
.Z Unix compressed file