The existence of “spikes” with very short time scales (1 to 10 ms) in the decimetric radio spectrum emphasizes the necessity of building radio instruments with very high time resolution. Therefore, we are planning to build a multi-frequency decimetric radioheliograph at the radioastronomical station of the Observatoire Royal de Belgique (Humain, Belgium). The existing array primarily devoted to observe at 408 MHz will constitute the starting structure of the project.