Abstract：Generally speaking, wave equation forward modeling is closely related to wave equation migration except that no forward modeling corresponds to Stolt's f-k migration. It is found that severe superposed-frequency effect occurs in, f-k forward seismic modeling. Hence, we put forward an improved forward formula and the corresponding calculation method that includes the following clever measures: (1)to remove the periodical influence of finite discrete Fourier transform by using amplitude attenuation factor, (2)to use two Sinc interpolations in interpolation mapping so as to eliminate false event noise for improved calculation efficiency, and(3)to adopt time-depth and depth-time conversions to make f-k forward modeling suitable for the case where there is weak latexal velocity variation besides vertical one. Experimental results show f-k forward seismic modeling is a practical method for wave equation forward modeling because it has some advantages similar to those in f-k wave equation migration, such as high efficiency, no restriction on formation dip angle, good stability and so on.
