Cambridge Aero Instruments turnpoint file format

File format

• This is a plain ASCII text.
• Lines starting with an asterisk are treated as comments and ignored
• Lines defining a turnpoint contain 7 fields, separated by commas. The final field is terminated by the newline.
• Format notation:

  9	represents a digit in the range 0-9. Numeric fixed length values are padded on the left with zeros
  X	represents an alphabetic character in the range A-Z or a-z
  T	is a digit or capital letter
  t	is any printable character
  [tt]	represents a single character chosen from the list enclosed by square brackets
  {m,n}	indicates that the field is variable length and must contain between 'm' and 'n' characters

  Any other characters in a format must appear exactly as written.

• Field definitions:

  Field	Format	Description
  Turnpoint number	9{1,4}	A unique number identifying the turnpoint.
  Latitude	11:22.222[NS]	1=degrees as 99, 2=decimal minutes as 99.999, N=north, S=south. This is a fixed format field.
  Longitude	111:22.222[EW]	1=degrees as 999, 2=decimal minutes as 99.999, E=east, W-west. This is a fixed format field.
  Height AMSL	9{1,5}[FM]	9=height, F=feet, M=metres.
  Attributes	X{1,5}	At least one attribute. The first code gives the purpose of the point described by this line. The rest add information, e.g. TA indicates a turnpoint on an airfield and TLASF indicates a turnpoint on a landable airfield that can also be used as a start and/or finish point. See below for codes and meanings.
  Turnpoint name	t{1,12}	A required text string. The BGA convention is to reserve the first 4 characters for the trigraph followed by a space, i.e. "TTT t{1,8}".
  Description	t{0,12}	An optional text string: Cambridge and Winpilot programs and instruments stick to the 12 character limit. LK8000, SeeYou and XCSoar can handle a longer field but restrict the overall line length to 255 characters. LK8000 wraps the text on whitespace if its too long for the box, so can display up to three lines of approximately 20 characters each. XCSoar doesn't wrap lines, so is limited to displaying approximately 20 characters. Zander instruments restrict the field to 9 characters.

Example turnpoints

31,57:04.213N,002:47.239W,450F,T,AB1 AboynBrg,RdBroverRDee
251,52:11.179N,000:06.674W,254F,TA,GRL GrnsdnLd,Clubhouse

Turnpoint attributes

Cambridge documentation defines the following: