A fundraiser for the Royal Flying Doctor Service, the very first Outback Air Race was held in 1996.
A good friend of mine was involved in the organisation and told me how judges literally sat under the nominated start and finish points armed with a clipboard and stop watch looking up into the sky to time when planes crossed the nominated points. The process was, of course, not very accurate, lacked good evidence and the judges ended up with sunburned faces and stiff necks.
We discussed better methods and for a subsequent event the organisers purchased a number of Garmin GPS III units and I developed a spreadsheet that read the GPS data files and calculated the results – based on differences between the nominated and actual elapsed times and by determining the time and position at which each plane was closest to the start and finish points.
The Garmin GPS III units were excellent units for their time and although they had very good screens and menus they had two major limitations:- 1. memory limited them to storing only 1,024 points of data (around 17 minutes at 1 point per second); and 2. in addition to batteries required for powering the units they also relied on an internal time clock battery that after a number of years required replacing by a technician at prohibitive cost.
Over the years, from one Outback Air Race to another, the scoring system was improved and when the Garmin internal batteries started to die the Garmin GPS III units were replaced with Holux M-241 data loggers. The purchase cost of each Holux M-241 was less than the battery replacement cost for the old Garmin units yet the memory capacity went up to about 130,000 points (over 35 hours).
The scoring system was re-written to cater for the different units in terms of both the data extraction processes and the different data structure.