Impulse response QC: v = 2000 m/s.
The input velocity model is an ISO model with constant value of 2000m/s. The left panel shows the input trace, which is generated by the forward modeling in the model with four horizontal reflectors (z=1000m, 2000m, 3000m, 4000m). The middle panel is the RTM migration image. The right panel shows the stack result in the middle panel along horizontal direction. By comparing the left and right panels, RTM proves its high precision by accurately restores the reflector’s depth positions and amplitude information.
Impulse response QC: v = 2000 + 0.15z m/s.
The input model is an ISO model with the velocity growing linearly in the z direction. The left panel shows the input trace, which is generated by the forward modeling in the model with four horizontal reflectors (z=1000m, 2000m, 3000m, 4000m). The RTM migration image is shown in the middle panel. The right panel is the stack result by summation the data in the middle panel along horizontal direction. The right panels shows that RTM not only accurately recovers the reflector’s location, also precisely restore the reflector’s amplitude.
Impulse response QC (v = 2000): timing and spectrum
The left picture shows two curves, one is the input trace in time domain, the other is the middle trace of the migration image in depth domain. The right picture displays their spectrums in frequency domain. The velocity model used in RTM is a constant model with v=2000 m/s. These two curves are perfectly overlaps on both pictures, which implies that RTM has precisely preserve the input trace timing and spectrum information.