The Model Accuracy software provides levels of confidence in GRIB predictions by using statistical and other analytic techniques to evaluate GRIBs in the context of boat performance. The analyses are time and location sensitive, and take into account variations in GRIB data granularity. Mathematical techniques are used to clean the "noisy" data that is often encountered in ocean deployment, so as to provide consistent predictions that can be relied on for tactical decision making. The predictions are delivered to the user in numerical and graphical format, thus providing both very precise prediction information as well as easy-to-comprehend overviews that raise the user's understanding of the prediction.
TWS Graphical Plot:
The graphical output shows how the predictions from the various GRIB sources correlate with the observations from the boat's instrumentation.
The GRIB sources are color coded, and the tagged with markers to indicate GRIB deliveries (green squares) and GRIB prediction time points (red circles). This example illustrates the output for True Wind Speed, and a similar graph is provided for True Wind Direction.
RMS: Root Mean Square
The numerical output from the analyses provides several quantitative indicators of the reliability of the GRIB predictions, for each GRIB source. These numbers are summarized into a final "ERROR" value, to allow navigators make a quick decision of which GRIB source to trust, when there is no time to consider the component values.
Example: if the COAMPS model is the best performing GRIB, but is always 12 degrees right of the actual TWD and 1.5 knots above the actual TWS logged by your boats sailing instruments, you would simply “calibrate” the forecast here with your routing software. This way you are now routing off the best possible GRIB file with no trend errors.
Once Model Accuracy has provided you the recommended calibrations for TWS and TWD for your best performing GRIB, you can enter those calibrations here in Expedition Sailing Software.