Global Positioning System Satellite Almanacs and SEM Program

GPS is a satellite-based radio navigation system developed and operated by the U.S. Department of Defense. We provide current GPS almanac and status files as well as historical data for the past month. Also available for download are the Almanac and Status Update Utility (ALMSTAT) and System Effectiveness Models, WSEM36 and WSEM103.

• Current GPS Almanac and Status
• Historical GPS Almanacs and Status
• Almanac and Status Update Utility—ALMSTAT (EXE, 2 MB)
• System Effectiveness Model
  • Single Location Users—WSEM36
  • Worldwide/Regional Users—WSEM103