Cross-Country with XCPAS

Introduction:

XCPAS stands for Cross-Country Planning and Analysing Software. The package can be downloaded without any costs from my home page http://home.wxs.nl/~kpt9 and is also available through the home page of the Dutch Soaring Association http://home.wxs.nl/~zweefnl.

The software package is suitable for private use but especially also for planning and analysing multi day competition flights in different classes. The Dutch Sporting Commission for Soaring uses XCPAS to evaluate in detail badge flights and record flights. For several years now the package has been in use at the Dutch Nationals as well as at other multi or single day competitions like the Summer Games, the Youth Games, etc. Several private pilots use XCPAS to plan and evaluate their own soaring performances. The package is written in english, so XCPAS is available for international use. On the home page of IGC, XCPAS is mentioned together with other packages like Strepla, SeeYou, TaskNav, etc. as suitable for the analysis of logger flightdata.

However in fact XCPAS is not at all limited to that purpose alone, as I will explain here after.

Special features:

Special features of XCPAS are the automatic design of tasks by a PC or laptop, the manual design of personal tasks for fixed and free flights and the design of competiton tasks for Races and AAT's directly on the graphics screen, and most interestingly the fully automatic analysis of all these types of flights, including those with outlandings. An aspect just recently finished, is the creation by XCPAS of an ascii file with all flight data of interest for use by a points accounting program like that of my friend Roel Kuil. A manual transfer of data between the two types of programs is thereby a matter of the past.

Most logical features are the generation of task sheets with detailed numerical and graphical information, the production of detailed barograms, downloading of flightdata from different types of GNSS recorders (loggers), the editing of waypoint files, etc. Of course all these features are available in the package.

Recent update:

In the last couple of month, again a lot of attention was given to XCPAS to update the package considerably. This was quite due after a somewhat longer period of attention to other matters of my life. I like to thank all pilots who helped and inspired me quite a lot in these days, particularly also for the testing work they did. My special thanks go to my friends Ken Sparkes, Peter Zander, Ruud Holswilder, Roel Kuil and Bas Seijffert. And last but not least of course to my son Ronald who already for a much longer period came up with essential contributions to bring XCPAS to the current state of possibilities and user friendliness.

Program Control:

XCPAS has been developed in Quick Basic 4.5 and uses so called compiled routines in full windows of Windows95/98/ME/XP. Control is mainly from the keyboard, so a short period of (rsi free) familiarisation is required. Especially the easy accessible function keys F1 up to F12 play an important role in controlling the XCPAS package. Figuur 1 shows the opening screen. In fact this is the main menu, clearly indicating that via these 12 keys the most important routines of XCPAS are activated. A submenu gives access to a number of other functions of XCPAS.

The different screen displays of the package give short instructions to expedite a logical program evolution. More over a short form manual is included in the package.

Technique:

The double precision goniometric calculations in spherical geometry for distances and headings use the FAI 1995 radius of the earth of 6371 km. Co-ordinates of waypoints and control areas comply with the WGS84 system and have an accuracy of 0,001 min. Geographic features play a minor role in XCPAS. Only specific boarder lines are indicated on the graphics displays.

The startline is perpendicular to the initial course line of the first leg of the task, the finishline is perpendicular to the final course line of the last leg of the task. In the automatic evaluation of start times and finish times, interpolation is used to assign these times to the actual crossings of log traces with the start line (or start circle) and the finish line. In this way a flight time accuracy of 1s and a position accuracy of a few meters is attained. The radius of a circular start area, as used in a multi point start system, is subtracted from the total task length since this radius is not a part of the task.

The accurate automatic computation of the best distance flown in an AAT task is performed in three iterative steps. Only in the last iteration the final selection of the best GNSS points of the log trace is made. For special cases a manual method used in earlier versions of XCPAS is still available as backup. In the automatic analysis of flights, the correct visits to waypoints in Races and area's in AAT tasks are checked. For outlandings the best distances flown are evaluated.

The XCPAS package has been developed on a 233MHz machine running under Windows ME. In competitions, a fast handling of a large number of files is important, so it may be wise to use then more powerful machines. For private use however, XCPAS runs comfortably already on quite ordinary PCs or laptops.

Several international waypoint files are included in the package or can be downloaded from my home page or that of John Leibacher. Format conversion can be done with one of the routines of XCPAS. The waypoint file Terlet.wpm for Holland and part of Germany has points accurately related to well described ground features and is available in this form mainly because of the activities of Theo van ’t Rood, member of the Competition and Selection Commission. All waypoint files can easily be modified or further extended by the user.

Some examples explained:

Figuur 2 shows the results of the automatic task setting routine PC-Tasks for a 300 km triangle with a "remote" startpoint relative to Terlet. Airfields may be used as turnpoints except e.g. Eelde and Beek because these fields do not allow glider activity. PC-Tasks tried 14083 cases and came up with 15 legal options. The order of computation is random, so next time the routine PC-Tasks may come up with some different solutions.

Figuur 3 shows in the Planning routine solution 07 from the 15 found by PC-Tasks in a graphical way. The benefit of using a "remote" start point when designing cross-country flights is clearly shown in this particular option. All turnpoints of the task are relatively close to the home airfield (here Terlet, situated about halfway on the first leg of the triangle).

Figuur 4 shows the result of a manual task setting activity with the routine Planning.exe. Terlet is the starpoint of the task. The design of tasks takes place directly on the graphics screen, so that one sees the task develop step by step. In this case a personal task is created with a length of a little over 280 km when the task is finished in its current design. The method is simple and fast. The departure point can iniatally randomly be chosen from the waypoint file in use. Different possibilities are available to modify the design during its creation or after saving with a suitable.

Figuur 5 shows the finished design of an AAT task made with the Planning.exe routine. The areas are assigned to specific reference points that are waypoints of the standard waypoint list. Again, the starting point is Terlet. Control zones can easily be avoided by using a limited radius of the areas and suitable radials. While designing an AAT task, XCPAS will initially project at the reference points, circular models of an AAT area with two perpendicular orientation lines. Using this model it is quite easy to define the actual AAT areas for the task in mind.

Figuur 6 gives the example of the log trace aex.igc in the AAT task SP03. The presentation is done in the Analysing routine. The proper visits of the areas assigned to Raalte, Balkbrug and Coesfeld are clearly visible. It looks like the CTR of Twenthe has been violated. However, checking that by moving the cursor (small red circle) alongside the log trace over that area, it shows that the AEX is far over this CTR all the time.

Figuur 7 shows a detailed view on one of the characteristic points of the SP03 task, in this case the start point. By moving the "cursor" over the log trace, detailed "on line" flight data are displayed at the bottom of the screen.

Figuur 8 shows the result of the automatic analysis of the performance of the AEX and the verification on the correctness of the execution of the flight. The flight data as presented here can be added to a simple ascii table for further use in a points accounting program like that of Roel Kuil mentioned before. This has been developed and tested recently and works fine.

Figuur 9 shows the first lines of this ascii table, in this case with some results of the WGC in Mafikeng for the speed class on day 8.

Figuur 10 shows the barogram of the flight of the Duo Discus AEX flown by Rob Looisen and Frits Gielens. Using the function keys F2 up to F4 a detailed height analysis is possible. Still a more detailed analysis can be done with the Analysing routine as indicated in Fig. 7.

In conclusion:

The development and maintenance of the software package XCPAS for soaring is quite challenging to me, though very time consuming .Through the years I have, together with other people spent hundreds of hours to achieve the current level of quality and user friendliness.

At this moment the package fulfils very well design and analysis demands of private pilots and competition leaders. The package complies with the criteria of the FAI described in Annex A of the Sporting Code. Commercial considerations have never played a role in my mind: XCPAS can be downloaded for free from my home page in its entity as mentioned above. I consider XCPAS as my personal contribution to the wonderful sport that gliding is.

Karel Termaat