Anti-Alias:  Complex Faults

Again same data, same parameters, different software

Competitor	Tsunami
View Larger	View Larger
View Larger	View Larger

Better job of imaging the faults and higher frequencies

Usually one thinks of how steep the dips are when choosing an aperture, and an anti-alias filter setting. However, imaging faults is also a function of aperture and anti-alias filter setting.

Faults dip at an angle as well, and we aren’t just imaging the flat events, and the offset created by the faults. We are also imaging energy that is reflected off of the face of the fault. This is often subtle, but it is what makes the fault stand out more, and makes it more visible. To image this energy off the face of the fault means that we have to treat the fault as if it were a dipping event. So the steeper the fault is, the greater the aperture should be. Also, opening up the anti-alias filter ( making the factor smaller, or the distances smaller) will put more energy on the fault face. 

When you think about the fault face being an event it become more intuitive, however people often just look at the flat sediments and think that’s all they are imaging when imaging faults. If the faults aren’t imaging that well, opening up the aperture, and relaxing the anti alias filter will image the faults better.

Note that in the Tsunami image, the sediments are imaged right up to the salt boundary while the Competition has gaps near the salt face.

The Tsunami image also has better imaging of higher frequencies.