NGSShutdownScreenOn October 1, 2013, the U.S. Federal Government shut down and furloughed 800,000 non-essential workers. While services considered essential remained active, those considered non-essential services, like the National Geodetic Survey’s Online Positioning User Service (OPUS) were shutdown. OPUS is a free, online GPS post-processing service. If you try to access, the screen to the right will be displayed:

For those of you who rely on OPUS for GPS post-processing, there are seven other free online post-processing services available that produce positions comparable to OPUS.

Here is a list of the seven free online GPS post-processing services:

  • CSRS-PPP: Canadian Spatial Reference System, Natural Resources Canada
  • AUSPOS: Geoscience Australia
  • GAPS: University of New Brunswick
  • APPS: Jet Propulsion Laboratory
  • SCOUT: Scripps Orbit and Permanent Array Center (SOPAC). University of California, San Diego
  • magicGNSS: GMV
  • CenterPoint RTX: Trimble Navigation

Click This Link to read a great article written by Eric Gakstatter of with a report on how all of these free online GPS post-processing services compare, including OPUS.