A dedicated antenna array for radio detection of Extended Air Showers

International audience; Radio pulses associated with Extended Air Showers (EAS) produced in terrestrial atmosphere by High EnergyCosmic Rays (UHECR) of energy 10^17 eV and above, are now routinely observed by dedicated radioinstruments on ground. This may offer a new and appealing way for elucidating the nature and origin ofinvolved primary particles, an open question still unsolved.Unfortunately, the high occupancy of the electromagnetic spectrum by undesired signals from natural andanthropogenic origins has made unambiguous EAS radio detection a challenging problem. Former attemptsbased on timing coincidences from several independent radio antennas, or using auxiliary triggering byconventional particle detectors, are still not fully satisfying.We present here a solution based on real time, coherent radio detection by using a small array of 10x2 crosspolarized dipoles, distributed over a 150m x 150m surface area and operated in continuous sky surveyingmode.Preliminary results obtained with the new system are briefly reviewed and discussed.The final detection scheme will be achieved by using on line, fast computing software based on a dedicatedunsupervised recognition algorithm.The new array is a part of the CODALEMA experiment located in Nançay radio astronomy observatory(France).