Our first synthetic test of the AMO operator is a simple diffraction in a constant velocity medium. We modeled a common-azimuth data set over a diffraction point with an offset of 500 meters and a regular midpoint grid 20 by 20 meters. The AMO operator was designed to rotate the offset azimuth of the data by 30 degrees. The results are compared with the modeled data in Figure 17. Azimuth moveout has succeeded in reconstructing the true geometry of the desired output, though it did not behave perfectly with respect to the amplitudes and boundary effects. The corresponding AMO impulse response is shown in crossline and inline sections in Figure 18. For simplicity, this impulse response doesn't include the derivative filter required for the complete definition of AMO. Figure 19 illustrates the antialising applied to AMO. The ``top'' view in the time direction shows how the antialiased AMO operator is constructed from the flat-dip and steep-dip parts.

Figure 17

Figure 18

Figure 19

11/12/1997