An official website of the United States government
Here's how you know
A .mil website belongs to an official U.S. Department of Defense organization in the United States.
A lock (lock ) or https:// means you’ve safely connected to the .mil website. Share sensitive information only on official, secure websites.


  • Files available:
    • GPS-satellite orbit + clock files (IGS .sp3 format)
    • GPS-based receiver- and satellite-clock solutions (IGS .clk format)
    • Earth-orientation files (IGS .erp format)
  • Each file provides 24 hours of post-processed solutions.  These files are also available via anonymous ftp at
  • File name convention:
    • usn15002.sp3 provides solutions for GPS week 1500, day 2 (Tuesday), midnight-to-(almost) midnight.
    • Similarly, usn15002.erp, usn15002.clk.
    • general format: usnwwwwd.sp3, .clk, .erp
  • Available ~ 16:00 UTC of following day.
To learn more about these products, click here.  |  |  Navy FOIA  |  DoD Accessibility/Section 508  |  No Fear Act  |  Open Government  |  Plain Writing Act  |  Veterans Crisis Line  |  DoD Safe Helpline  |  Navy SAPR  |  NCIS Tips  |  Privacy Policy  |  Contact Webmaster
Commander, Naval Meteorology and Oceanography Command  |  1100 Balch Blvd.  |   Stennis Space Center, Mississippi 39529
Official U.S. Navy Website
Veteran's Crisis Line