Seismic exploration process enabling the suppression of ghosts due to reflections at the water surface, and process for processing seismic data in order to suppress these ghosts

Process for marine seismic exploration at at least two different depths by means of streamers, each including a set of hydrophones, the acquisition of data at the different depths being performed in a single exploration region, wherein, in said exploration region, the position of the streamers and the hydrophones when acquiring seismic data at a first depth is independent of the position of the streamers and hydrophones when acquiring seismic data at a second depth,

• the process further including the processing of seismic data acquired by hydrophones at the two depths in order to obtain output traces in which parasitic surface reflections have been suppressed, with the output traces being obtained by linear combinations of the seismic data in the frequency domain, with the coefficients of said linear combination being calculated, for each frequency, on the basis of seismic data acquisition positions and depths at which the output traces are to be obtained, and on the basis of the propagation equation of the waves in the water layer located above the hydrophones.