Platform Location and Data Collection by Satellite Systems the EOLE Experiment

A technical description of the EOLE location and data collection system with 480 constant level balloons released in the Southern Hemisphere is presented : the EOLE satellite contacts successively each platform, acquires and stores range and range rate data allowing computation of the location of each transponder and meteorological data measured by the plat form sensors. This information is stored on board and then read out by telemetry upon reception of a command from ground stations. The experiment itself is described and the main technical results are analyzed ; the ultimate location accuracy of the EOLE System was found to be of the order of 300 meters for fixed platforms but, some difficulties concerning the Location of drifting balloons were encountered due to the necessity of compensating the Doppler shift for platform motion. The main scientific results are briefly presented as well as some post-EOLE experiments. Future developments of this type of location and data collection system are described as a conclusion.