• C4G-TOP: C4G Online Processing - powered by Trimble Online Processing App

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

  • OPUS: NGS GPS Data Processing Online Positioning User Service
  • 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 GPSWorld.com with a report on how all of these free online GPS post-processing services compare, including OPUS.