Spaceflight Live Tracker – a pair of open-source iPhone applications for tracking the flight of high-altitude latex meteorological sounding balloons and in-field prediction of flight path and landing location are now available on github. The repo contains two xcode projects and supporting server side scripts. Location data is transmitted from the SpaceTrans application on one iPhone contained in the payload of the balloon as long as it is below cell tower range. This data is stored on the server and retrieved by the SpaceCalc application running on the second iPhone being used in the field. There is also a separate web interface at `predictor/flightmap.php` for viewing live flight data through a browser. The SpaceCalc application also calculates the burst altitude and ascent rate of the balloon and uses this data to generate the predicted flight path and landing location of the balloon based on the user’s current location. Prediction data used by both the xcode and flightmap are generated by Jon Sowman’s CUSF Standalone Predictor.
Read all about the apps here and see footage from 100,000 ft above the earth here.