On Sun, 2010-12-19 at 13:35 +0100, martin.kopp...@gmx.de wrote: > Until now, I have just used what came with a standard installation and > downloaded waypoint data now and then, but now I find there are some > minor glitches in the data I found, some abbreviations used truncate > the TP or field names beyond recognition, a few fields even seem to be > missing, some are already closed, and while trying to correct them, I > find it is a bit strange to have turn points and airfields in the same > list and then airfield info in yet another. That makes keeping them up > to date and synced a bit difficult. > Whether airfields are mixed in with turnpoints depends, I think, on how the national association builds the national turnpoint file.
In the UK, the BGA list is strictly a list of turnpoints. There are apparently some airfields on it, but they all turn out to be turn points that are on or near airfields and so have got the A and L attribute flags set. As you might expect, these are all gliding fields. Those of us with lists of non-gliding airfields and other landable places keep them in a separate list thats configured as Turnpoints 2. > Now, in this data, airfields have all the data that is relevant for > them as far as they act as turnpoints, but that's it, then. > This isn't so surprising when you consider that the file format is merely the Cambridge Instruments (CAI) turnpoint file. > There is apparently one more file that can be used, and that is an > airfields file in txt format, which - as far as I understand - needs > to list the airfields with the same names as used in the WP file, but > can hold additional info such as RWY info, radio frequency and > comments. > That's needed because, although the CAT turnpoints file has a descriptive field as well as a name field, both are quite short. As far as I know both are defined to have a maximum size of 12 characters. ***** Question for XCSoar developers: what is the maximum size that ***** XCSoar will accept for the 7th field (the description)? > Now, things get difficult, respectively editing them takes a lot of > effort. > Given that XCSoar needs two additional pieces of data: - the home field - up to a screenful of displayable information about airfields the decision was taken to put that in a separate 'airfields' file rather than taking the turnpoint list differ from the well known CAI turnpoint format. This makes sense when you realise that many countries (and the Soaring Server) distribute turnpoints in this format. Do we really want yet another turnpoint file format that must be maintained and distributed? I don't think so. > Woudn't it make sense to: > > A) Have the airfields and all the corresponding info in one airfields > file that can exist in parallel to one (or more) turnpoint file(s)? > There's an alternative way of going about it that some of us are investigating. That is to develop a list of mandatory and optional fields that can be used to describe airfields and to gather a set of airfield descriptions that fit this format. This airfield database can be held in almost any convenient format (an SQL database, an XML file or a CSV file are the obvious ones). Then all you need is a program for maintaining the airfield database and another program that can generate loadable file(s) for XCSoar, LK8000, Cambridge, SeeYou.... in short, a converter program for any instrument or program that needs the access the airfields database. IMO a spreadsheet isn't suitable as the master file because: - different spreadsheet programs have incompatible file formats. There are even incompatibilities between different Excel versions. - A spreadsheet isn't good at validating this type of date, for instance to make sure a turnpoint isn't entered twice by mistake or to validate turnpoint attributes. Note that, as the data needed to describe a turnpoint is a subset of that needed for an airfield, this database can also be used to maintain turnpoints by adding a field that says whether an item represents an airfield or a turnpoint. Martin ------------------------------------------------------------------------------ Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ Xcsoar-user mailing list Xcsoar-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xcsoar-user
