If GPS failed before 100,000 ft (and it looks like any commercial GPS would), what about the altitude charts on the project's homepage?[0] How were they generated? Can that data-gathering method qualify it for the Carmack challenge?
As to how they were generated, the charts are labelled. The first shows raw acceleration data, plus the first and second integrals of that data. The second shows data from a _simulation_, which was tweaked after the flight to approximate more closely data that they do have.
0: http://ddeville.com/derek/Qu8k.html