Tracks like those shown are the result of applying .kml output files from a datalogger to Google Earth.  There are other output file formats which can show course, speed and altitude at any given point around the course.  Very useful.

 

The use of data loggers was how USAR did all of their scoring and turn judging.  You can see from the tracks that a blown turn will be painfully obvious!

 

As we move towards a real-time display of aircraft tracks, an incemental step is the display of such tracks.

 

Just about any data logger can be used as long as it provides the correct output file types... but the unit that is becoming the SARL standard is the GlobalSat DG-100.

 

This unit can be purchased on line from many sources for around $70.00.  It can be found from $70 - $112.

 

Here are some $70.00 sources as of 27 April, 2008: