Jet Stream - http://squall.sfsu.edu/crws/jetstream.html
Flight Prediction -http://nearspaceventures.com/w3Baltrak/readyget.pl
Here are links to various sites that I have found to be a tremendous help in establishing this program.
University of Idaho VAST
Idaho Space Grant Consortium
Montana State University Borealis
A good site that has many schematics for various projects.
An easy Offset Attenuator Project for RDF.
Near Space Ventures
Paul Verhage's site
MicroHunt DF Transponder
amateur radio high altitude ballooning (arhab)