Verify QC Tides is a real-time tidal estimation module within the Verify QC software suite and has many advantages over conventional methods, such as tide gauges or tidal prediction software.

The module uses highly stable, accurate positions from the VERIPOS Ultra or Apex positioning service in conjunction with proprietary processing techniques. Since the services provide real-time decimetre level accuracies, it is possible to use these positions to detect height variations relative to a vertical reference offshore. Heights are typically determined to an accuracy of 10-15cm.

To achieve this, the real-time tide estimation process has to manage height variations caused by vessel motion and by inaccuracies in the GNSS position calculation process. Information and results are presented using numerical and graphical displays within the Verify QC software.

Verify QC Tides provides two real-time tide observations. The first method estimates a Geoid tide relative to a model, either EGM96 or EGM2008, which is a global approximation of Mean Sea Surface (MSS).

The second method derives MSS using a Verify QC Tides filter and then estimates the tide relative to this surface. This observation, called Verify QC Tides, is independent of uncertainties in the Geoid model.

The Verify QC Tides observation is more accurate since its vertical reference (MSS) is accurate to the cm level. The Verify QC Tides estimates provide the real-time total variation from a vertical reference (MSS for Verify QC Tides or EGM model for Geoid Tide).