On 31 October 2020, anonymous ftp access will officially be discontinued at CDDIS. Beginning October 1, 2020, CDDIS will bandwidth limit ALL IPs using anonymous ftp to just 50KB/s and will limit simultaneous downloads to only 3 per IP address. 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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DORIS product holdings

The CDDIS archive of products derived from DORIS measurements consists of solutions provided by analysis centers of the International DORIS Service (IDS), as defined by the service’s analysis coordinator and approved by the Governing Board. Products derived from these DORIS data include precise satellite ephemerides, station positions and velocities (input to the derivation of the ITRF), time series of station coordinates, EOP (polar motion, length-of-day), and time derivatives of vertical Total Electron Content (TEC).

The format and time span of the products varies by product type. IDS analysis centers generate solutions of DORIS station positions on a weekly basis in SINEX (Software Independent Exchange) format. In addition, some ACs provide time series of station coordinate solutions in the STCD (STation Coordinate Difference) format; this format provides Cartesian and ellipsoid coordinate determinations and their formal errors allowing for the generation of point position time evolution plots. Other DORIS products include cumulative solutions of station velocities and positions at a reference epoch, geocenter determinations, EOPs, and satellite orbits. The DORIS data processing group generates ionospheric correction values from DORIS measurements.

Product formats:

  • SP3 and SP3c formats
  • Software INdependent EXchange (SINEX) format

The archive of IDS products is organized in subdirectories by product type (e.g., time series of station positions, EOP values, orbits, etc.).

The starting directory for these files in the is:

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

A complete description of directory structure and filename specifications is available from the IDS website: http://ids-doris.org/analysis-documents/struct-dc.html.