XCSoar polar file format

This page was last updated on 01 December, 2009.

Format

XCSoar uses the Winpilot polar file format, which seems to be almost entirely undocumented: there appears to be no published specification for it, just examples. Even the Winpilot site assumes you'll use the file from their collection that best matches your glider and will not attempt to edit it. By testing XCSoar it has been determined that:

• Comment lines, which have '*' as the first character, are ignored. They may appear both before and after the data list. Comment lines never contain any significant data.
• The newline separator may be CRLF (DOS/Windows) or LF (Unix/Linux).
• All the values must be on the same line.
• Values must be separated by commas, though spaces and tabs may appear on either side of a comma. Spaces may precede the first value on the line. A newline may terminate the last value.
• Blank lines are NOT permitted unless they follow the values line. If encountered, they are treated as End Of File.

XCSoar quirks

• No warning is given if the file is wrongly formatted and/or is missing values. You can only tell if the file was correct by going to Info:Analysis and inspecting the polar.
• A number of polars are built into XCSoar. These are selected by setting the Type on the System setup Polar page (page 7).
• Polars for other gliders are added by finding or creating a Winpilot format polar file. This is put in the XCSoarData directory. It is selected from the System setup Polar page (page 7) by setting Type to WinPilot file, clicking Polar file and selecting the appropriate file name.

Examples

1. A file in the format preferred by Winpilot. All whitespace is tabs.

   
   *H-201 Std Libelle      WinPilot POLAR file: MassDryGross[kg],  MaxWaterBallast[liters], Speed1[km/h], Sink1[m/s], Speed2, Sink2,   Speed3, Sink3
   304,    0,      97,     -0.79,  152.43, -1.91,  190.54, -3.3
   
   

2. A prettier layout. Comments have been split over multiple lines but the data values are on the mandatory single line with a tab after each comma.

   
   * H-201 Std Libelle
   * =================
   * WinPilot POLAR file:
   * MassDryGross[kg], MaxWaterBallast[liters], Speed1[km/h], Sink1[m/s], Speed2, Sink2, Speed3, Sink3
   304,    0,  97, -0.79,  152.43, -1.91,  190.54, -3.3
   *
   * End of file
   *