Difference between revisions of "DataFiles"

Revision as of 18:28, 30 May 2012

VRtool needs data to perform calculations. Those have to be loaded in the program before you can use the track designer or the weather routing module, for example. These data files are charts, wind forecasts and polars.

Charts

Vrtool uses a custom vector chart format files, with extension .CHT. The program comes with a simple world map (world3.cht). You can find more detailed files in vrtoutoulz or in the chart lib. Download and save files to the vrtool directory. To load a chart, use menu option File > Open Vector Chart...

Tip: A good world chart is c_gshhs_i.cht (from vrtoutoulz [1] ). VORG 11/12 uses this file. It was ported by Ricoo from Global Self-consistent, Hierarchical, High-resolution Shoreline Database [2] .

Wind forecasts

These can be obtained from a number of sources. Ultimately, all wind forecasts come from the GFS ( Global Forecast System, a world weather model updated NOAA every six hours), but regatta game providers do some processing in NOAA data. Vrtool can use winds from:

• Downloaded directly from the NOAA server using the vrtool's built-in NOAA import module. This method gives the earliest possible forecast updates, as the NOAA server is also the source for the other methods. This is also the most convenient way to import a grib covering the whole area of a race leg. Once the grib boundaries have been set in the NOAA import module, vrtool remembers them for subesquent imports. This makes subsequent updating of the wind grid a one-click process.
• From vrtoutoulz website - Set regatta server host to www.vrtoutoulz.fr/winds, point any location with the mouse and press F2. This will load a 10x10 degree wind grid.
• Load a GRIB2 format file ( p.e. files downloaded by UGrib or ZGrib ).
• From Virtual Regatta game files.

	For VR, you can use game winds (imported by vrtool from Firefox cache) or winds from vrtoutoulz.
	For VORG, you must import winds directly from the NOAA server (using vrtool's NOAA import module), or use vrtoutoulz winds.

After loading the wind forecasts you may use buttons to select a given forecast. Use buttons Ctrl-1 to Ctrl-7 or the buttons in the toolbar to display successive wind forecast periods.

Polars

Polars allow the calculation of the boat speed for a given wind speed and wind angle.

Vrtool can use two kinds of polar chart databases.

• Multi-sail polars - This is a new format with a set of polar data for each sail. This is the preferred format. Multi-sail polar database files have extension XML, and can be produced, imported and edited using the vrtool polar studio.
• Merged sail polars - This compact polar database format is available from sources like vrtoutoulz [3] . Extension .CSV.

Select the file and click load. Also select which database type you are using in the Winds > Polars tab.

Importing game winds and boat data

You can keep boat positions and winds updated by using the Firefox cache importer for Virtual Regatta and VORG. Read more about that in this tutorial.