A method for determining a particle impact on a sensor device comprising M sensing areas, each impact causing a variation of at least one physical magnitude of several sensing portions, said method comprising the steps of: determining an impact center sensing area, where the variation of the at least one physical magnitude is substantially maximal, allocating a result of a sum of the physical magnitude variations of a first set of N sensing areas, said set including the impact center area and other sensing areas neighboring said impact center sensing area, where N is at least 2 and is strict less than M.