notes

linux下fortran语言开发

This is an example of surface shooting but with
the shot buried deep in the model.  We have asked for primaries
from all interfaces.  However, when the shot is below an interface
there can be no primary reflection (the program figures this out).

You can ask for reflections from interfaces above the shot - these are
considered extra events. 

Notice how the range of takeoff angle gets wider as the shot approaches
the bottom of the syncline.  In file param the shooting search takes
place over all angles ( -180 to 180).