SUINVZCO3D - Seismic INVersion of Common Offset data with V(Z) velocity function in 3D suinvzco3d outfile [optional parameters] Required Parameters: vfile file containing velocity array v[nz] nz= number of z samples (1st dimension) in velocity nxm= number of midpoints of input traces ny= number of lines Optional Parameters: dt= or from header (dt) time sampling interval of input data offs= or from header (offset) source-receiver offset dxm= or from header (d2) sampling interval of midpoints fxm=0 first midpoint in input trace nxd=5 skipped number of midpoints (see note) dx=50.0 x sampling interval of velocity fx=0.0 first x sample of velocity dz=50.0 z sampling interval of velocity nxb=nx/2 band centered at midpoints (see note) fxo=0.0 x-coordinate of first output trace dxo=15.0 horizontal spacing of output trace nxo=101 number of output traces ", fyo=0.0 y-coordinate of first output trace dyo=15.0 y-coordinate spacing of output trace nyo=101 number of output traces in y-direction fzo=0.0 z-coordinate of first point in output trace dzo=15.0 vertical spacing of output trace nzo=101 number of points in output trace ", fmax=0.25/dt Maximum frequency set for operator antialiasing ang=180 Maximum dip angle allowed in the image verbose=1 =1 to print some useful information Notes: This algorithm is based on formula (50) in Geophysics Vol. 51, 1552-1558, by Cohen, J., Hagin, F., and Bleistein, N. Traveltime and amplitude are calculated by ray tracing. Interpolation is used to calculate traveltime and amplitude. ", For each midpoint, traveltime and amplitude are calculated in the horizontal range of (xm-nxb*dx, xm+nxb*dx). Velocity is changed by linear interpolation in two upper trianglar corners whose width is nxc*dx and height is nzc*dz. ", Eikonal equation will fail to solve if there is a polar turned ray. In this case, the program shows the related geometric information. Offsets are signed - may be positive or negative. ",