Earthdata login will be performing a 1-hour test on Friday, October 6, between 10:30am – 12pm EDT (14:30 – 16:00 UTC). Logins should not be affected if you have logged into your Earthdata account in the past year. If you have any issues logging in outside of this time period, please send a help request to

close window


Data Center Citation

Noll, Carey E., The Crustal Dynamics Data Information System: A resource to support scientific analysis using space geodesy, Advances in Space Research, Volume 45, Issue 12, 15 June 2010, Pages 1421-1440, ISSN 0273-1177,

Data Citation

CDDIS VLBI DB data, Greenbelt, MD, USA: NASA Crustal Dynamics Data Information System (CDDIS), Accessed [[enter user data access date]] at doi:10.5067/VLBI/vlbi_db_data_001.

Other standard citation formats may be used for this data set and can be found at the DOI Citation Formatter website.

More information about CDDIS data citations and acknowledgments is available.


  • Name: CDDIS VLBI DB data available from the Crustal Dynamics Data Information System (CDDIS)
  • Format: binary
  • Spatial Coverage: 90.0 to -90.0, 180.0 to -180.0
  • Temporal Coverage: 1979 - present
  • Temporal Resolution:
  • File Size: ∼20KB
  • Platforms: Very Long Baseline Interferometry (VLBI)


Very Long Baseline Interferometry (VLBI) ASCII files in the NGS card format.

Data Access

CDDIS VLBI DB data files are online.

Starting directory:

in subdirectories by year as follows:


Code Meaning
YYYY4-digit year
YY2-digit year
CCC 3-character month name
DD 2-digit day of month
TT 2-character database code
### 3-digit version number
gz gzipped file