Click the "New" button to create a new race. This creates a folder (named after the race) inside the Model Accuracy "Races" folder, in which prepared data, saved analyses, and analysis settings are saved, to allow you to quickly load your preferences in future analysis runs.

Model Accuracy analyzes the log files in a folder that you specify. It does not have to be where Expedition stores the files, although that folder is referenced for easy operation. You can view this quick reference by clicking on the (?) symbol to the right of the "Log Directory" label. The folder that stores the log files must contain only log files, so we recommend that you create a separate folder for the log files you want to analyze.

The "subfolder" method is the recommended method of organizing log files (and is necessary any time there are log files from different sources). Model Accuracy treats each subfolder separately. The log source name is set by:

• If the log files are in a subfolder, use the subfolder name.
• If the log files are in the specified log folder, Model Accuracy creates a subfolder called "Boat" and moves the files into that folder.
• If you are using Expedition as the log source, you can copy the log files from the Expedition log file folder to your log file folder. This make for a cleaner review process. Model Accuracy has a quick reference for the folder where Expedition stores its log files.

Tip: Even if you are selecting NOAA buoy data as log data to analyze, which requires fetching data from the internet, you still need to specify an empty folder where Model Accuracy can store the NOAA buoy log data

Model Accuracy analyzes the GRIB files in a folder that you specify. It does not have to be where Expedition stores the files, although that folder is referenced for easy operation. You can view this quick reference by clicking on the (?) symbol to the right of the words "Model Directory". The folder that stores the GRIB files must contain only GRIB files, so we recommend that you create a separate folder for the GRIB files you want to analyze.

The "subfolder" method is the recommended method of organizing GRIB files. Model Accuracy treats each subfolder separately. The GRIB source name is set by:

• If the GRIB files are in a subfolder, use the subfolder name.
• If the GRIB files are in the specified log folder, Model Accuracy uses the GRIB file name to work out the source name.
• For some well known sources the names are automatically abbreviated.

For example, if the GRIB folder has these files and folder:

there will then be three sources listed in the analysis:

Set mast height. This is the distance in meters from the water line to the anemometer where the logged wind data is captured.

Scale/Report Button:
If the Scale/Report button is set to Scale, the TWS of the anemometer and the TWS of the GRIB will both be scaled to the height that you have specified, using the same scaling formula as used in the Expedition Sailing Software. If the Scale/Report button is set to Report, no scaling is done (i.e., the raw wind speeds are compared directly even if they are predicted/logged at different heights), but the scaling factors that would be needed to bring them to the specified height are reported in the message window. We recommend selecting the REPORT option only for advanced level navigators/sailors who are comfortable with the equation of scaling. This is not required for NOAA buoys (when you click Prepare Data for NOAA buoys the mast height is set automatically)

True or Magnetic Degrees:
Select "True" or "Magnetic" mode. This is to determine the format of the wind direction stored in your log file. It is either True or Magnetic. If your log files capture TWD in degrees True, then select True. If your log files capture TWD in degree Magnetic, then select Magnetic. Consult Expedition, Adrena, ect... settings if necessary to learn if you are logging your information in True or Magnetic. NOAA buoy and Adrena log files are in True. Expedition files can be logged in Magnetic or True. NMEA log files can be logged in either True or Magnetic, consult you instrument settings before making this selection.

In this latest version of Model Accuracy you no longer have to select what type of log file format you are using in your analysis. Model Accuracy can now automatically detect the type of log file for Expedition, Adrena, NMEA, NOAA, AuBOM, and PredictWind file formats.

1. Navigate to http://www.bom.gov.au
2. Click an area of the country
3. Click the Observations tab
4. Click Latest Coastal Observations
5. Select an individual observation station
6. Note the anemometer height of observation station - enter the height into Model Accuracy when you perform the analysis
7. Download the .axf file
8. Store .axf file in the specified log folder on your computer

If selecting a NOAA buoy log file you must enter the 5 digit code associated with the buoy, and select "Fetch" to the right of the code entry space. All NOAA buoy codes are listed here: https://www.ndbc.noaa.gov. NOAA buoy data is only available for the past 45 days from when selected. Example buoy code: PVGF1 is Port Everglades.

Not all NOAA buoys have TWS and TWD data, so make sure to confirm yourself on the website of that particular buoy before selection.

Set boat data smoothing window. This smooths out the boat log data, removing large changes in short time period that are caused by, e.g., the swinging of the mast, short gusts of wind, etc.

Prepare Data - This feature prepares the log and GRIB data. It determines the earliest and recommended analysis start times, and the latest and recommended analysis end times.

Model Accuracy recommends using the Prepare Data capability before every analysis!

Model Accuracy permits you to prepare data for and then select more than one log file and more than one GRIB model at a time. Here you can select which log files and GRIB models you are going to analyze. Most analyses are complete by selecting "All". If you would like to focus in your analysis on specific logs or GRIBs you have that option in these drop down menus.

"All GRIB runs" creates an analysis on the freshest available data within the GRIB folder, reviewing all the GRIB files available.

"Single GRIB run" allows you to analyze only one GRIB file to compare against the boat log files. Model Accuracy will choose the GRIB file with a start time closest to the start time of the analysis window you select.

"Stepped" allows you to select time steps of 6, 12, 24, 48 hours within each GRIB file source to review its accuracy. This is helpful in determining the trends of each GRIB file for comparison.

Here you tell Model Accuracy exactly from when to when you want the boat log files compared to the GRIB files. The times must be within the range of the boat log files' data and the GRIB files' data.

Example: If you have Logs which cover Friday and Saturday, and GRIBs which cover Saturday and Sunday, Model Accuracy can only provide you an analysis of what took place on Saturday as that is the only time that has logs and GRIBs.

By clicking the Prepare Data button earlier in the set up process Model Accuracy is capable of determining the earliest start and latest times possible for analysis, and will provide you a "no earlier than" and a "no later than" recommendation. These time recommendations are the earliest and latest time where both GRIBs and boat logs overlap.

The "Use" buttons to the right of the recommended times allow the user to immediately accept the recommendations of the start/end time and use at as the analysis start/end time. Consult the Model Accuracy Manual "Warnings - Notes - Definitions" which is located at the bottom of this document for more information regarding the meaning of the recommended times.

Set analysis granularity. Model Accuracy can produce results accurate to the minute, but if that's too slow for a very long log you change the granularity to take larger steps through the log data.

Here you can move the GRIB model in time and space, and provide offsets for the TWS and TWD.

• The model can be brought forward or pushed back in time by giving a positive or negative number of minutes offset.
• The model can be moved north/south and west/east by giving positive/negative minutes of latitude and longitude.
• The model prediction for TWS can be increased or decreased by a percentage that is greater or less than 100%.
• The model prediction for TWD can be increased or decreased by a positive or negative number of dgrees.

Providing offsets for the time/latitude/longitude can be thought of as fixing possible causes for the errors in the model's prediction of TWS and TWD. Typically either only one of the sets would be used: TWS and TWD offsets, or time/latitude/longitude offsets.

Select the "Use" button to apply the offsets during analysis.

Select "Component Plots" if you would like to see the TWS, TWD and BAR graphical plots in addition to the statistical analysis provided.

Select "Analysis Plots" if you would like to see the TWS, TWD and Model Accuracy % graphical plots in addition to the statistical analysis provided.

Select "Save" to save your results and data plots for future reference, in the SavedAnalyses subfolder of the race folder created in Step 1. You must click "Save" before you click "Analyse". After analysis you can select "View" to see the saved analysis and plots of your data.