The GRAND (Giant Radio Array for Neutrino Detection) project aims at detecting ultra-high energy messengers (atomic nuclei, neutrinos, gamma-rays) coming from the most powerful sources in the Universe, with a 200'000 radio antenna array. Two prototypes have been deployed in 2023 in desert areas in China and Argentina, and the first dataset is currently being analyzed. In this internship, the candidate(s) will take part in this exciting phase of pioneering data analysis. Two possible axes of research will be proposed, based on the collected data at both sites or based on simulations, for a prospective study on the China prototype. a) the identification of specific signatures in the radio signals from cosmic particles. This will be used to discriminate efficiently against the background radio noise. b) simulations to assess the performances of a hybrid detector (radio antennas + scintillators) at the China site, to detect cosmic particles