Welcome to the
CDAWeb Database
Anonymous FTP Service !

The CDAWeb data service (at cdaweb.gsfc.nasa.gov) offers graphic, listing, subsetting and data computation services for a continuously increasing database of current and past Sun-Earth-Connections mission and ground-based data. As a complement to the CDAWeb data service, we also provide the publicly-released subset of the underlying database directly accessible as an anonymous FTP service (accessible at ftp://cdaweb.gsfc.nasa.gov). All data available from the FTP service are also available from CDAWeb itself; the major advantage of the FTP service is support for functions like "mget."

Relocation of Directories on SPDF/CDAWeb and NSSDCFTP Services: On 2012 September 24-26, SPDF re-named and re-structured its FTP and HTTPS accessible directories to create a unified structure that merged in the legacy heliophysics data holdings previously served by the National Space Science Data Center (NSSDC) on nssdcftp.gsfc.nasa.gov. The responsibility for the final archiving of heliophysics data has been transferred from NSSDC to SPDF (for non-solar instruments) and to Solar Data Analysis Center (SDAC) (for solar instruments). SPDF will also serve some legacy solar instrument data for awhile.

All heliophysics data and other files previously accessible separately from NSSDCftp or CDAWeb are accessible from any of the addresses ftp://spdf.gsfc.nasa.gov/pub, https://spdf.gsfc.nasa.gov/pub, ftp://cdaweb.gsfc.nasa.gov/pub and https://cdaweb.gsfc.nasa.gov/pub. Other SPDF services are unchanged.

A preliminary list of directories moved (current and new locations) is posted here. The list does not entirely reflect all of the final moves. Changes to CDAWeb data are listed first and the move from NSSDCftp is listed second.

General ReadMe for the CDAWeb data directories:


Mission data are located in pub/data directories for each mission, with subdirectories for specific spacecraft and instruments, followed by dataset directories for each instrument, and finally yearly or day of year (doy) directories containing data files that are mostly in Common Data Format(CDF).


Many of these individual data files have incomplete internal descriptions of the physical meaning of their parameters. Better metadata can usually be found in what we call "master CDFs". Master CDFs are CDF files that contain only the metadata attributes for a given dataset and its variables; these metadata improve on and generally over-ride the metadata in the data files.

All public CDAWeb master CDFs can be downloaded from:
or their corresponding skeleton files:


All CDF files can be opened and read with the CDF distribution software found here . The content of these data files joined with the master CDF metadata is best accessed (plot, list in ASCII, file download of selected variables and times) using the CDAWeb user interface at . These functions are also available via web services.


IDL users may also find useful the CDAWlib software library and the CDFX display and listing tool.

Comments are Welcome!

Please feel free to send your comments, suggestions, and other thoughts about this section directly to CDAWeb. Your suggestions are vital to improving service.

Page last updated January, 2017

Approving NASA Official: Dr. Robert E. McGuire, (301-286-7794),
Head, Space Physics Data Facility, Code 670
NASA/Goddard Space Flight Center, Greenbelt MD 20771 USA