Thank you very much for your time, GuyM...
It surely makes perfect sense now. To check if I understand correctly, let me sum up what I understood.
1-Algorithms (processing steps) ------> processing stages --------> Processing sequence(flow) to give an example,
(For instance, Kirchoff) ------------> Migration-------------------> All processing stages applied
There are different migration types such as Kirchoff, Stolt, Gazdag... these are processing stage of migration and each has different algorithms. To see which one is the best, we try all of them on a sampled data. Whichever gives best image that is the one. What we are doing here is called testing.
2- Also, I never thought that the data volume is that important. Thanks to advancing tech, it is now ,as you said, CPU bound, and the duration required to process a whole data to get an image of subsurface depends on processing speed of the computer, CPU. Now, I see why processing 3D data takes 4-12 months. First, It seemed to me like exaggerated. I thought how come it does take too long. it is a computer-related and should not be that long.
3- Here, you said... We do need to test each processing step separately, however. This is usually done on a representative subset of the data for speed.... by saying representative subset of the data, you meant first try it on a small scale, right ? For example, I have 3- component data, which means 3 representative subsets of data. To do what you said, I need to pick one component, say vertical, then first try all different kind of algorithms (again let say gazdag stolt..for migration) on this component then after finding the best one, apply it on other components, too. And do it for every stages(velocity analysis, migration and others ) that have different types of algorithms to find the best you have got.
Am I correct ?
PS:I realize that I am asking too much. The questions I have asked could seem to be very easy for some but not for me now. I started to processing data like one week ago. These are the questions that come to my mind while I was studying concepts of seismic data processing. I have a data processing flows for the data sets I have and I am reprocessing exactly the same flow as a beginner. I just want to understand what they are, why, how, and when....to learn this job.