1. A method for deblending seismic data obtained when surveying an underground formation, the method comprising: receiving blended seismic data gathered using simultaneous source acquisition; applying a first deblending technique, FDT, to the blended seismic data to calculate a signal model and a noise model; calculating residual data by subtracting (i) data corresponding to the signal model and the noise model from (ii) the blended seismic data; applying a second deblending technique, SDT, to the residual data resulting after applying the FDT; and creating an image of the explored underground formation using deblended data obtained by applying the FDT and the SDT, wherein the FDT and the SDT are different techniques.