Program sfexcitationic | Demo for excitation imaging condition
[SYNOPSIS]
sfexcitationic < Fv.rsf > Fout.rsf nb=20 nt= dt= fm=20.0 kt=300 jsx= jsz=0 jgx=1 jgz=0 sxbeg= szbeg= gxbeg= gzbeg= csdgather=y ns=1 ng=nx
[COMMENTS]
Note that excitation imaging condition has some multipathing artifacts.
The significance of this imaging condition is the cheap computation and
low memory requirement. (1) Cheap computation: only 2 times of simulation,
one for source wavefield the other for receiver wavefield, are needed for 
single shot imaging before stacking. (2) Low memory request: this imaging 
condition only asks for the excitation time and the amplitude. Therefore,
it differs from cross-correlation imaging condition which needs storing 
or reconstructing the source wavefield to cross-correlate with receiver
wavefield at each time step.

[PARAMETERS]
bool    | csdgather | =y |  [y/n] | 	
float   | dt | = |   | 	time sampling interval 
float   | fm | =20.0 |   | 	dominant freq of Ricker wavelet 
int     | gxbeg | = |   | 	x-begining index of receivers, starting from 0 
int     | gzbeg | = |   | 	z-begining index of receivers, starting from 0 
int     | jgx | =1 |   | 	receiver x-axis jump interval 
int     | jgz | =0 |   | 	receiver z-axis jump interval 
int     | jsx | = |   | 	source x-axis  jump interval  
int     | jsz | =0 |   | 	source z-axis jump interval  
int     | kt | =300 |   | 	output wavefield at time kt 
int     | nb | =20 |   | 	thickness of sponge ABC 
int     | ng | =nx |   | 	number of receivers 
int     | ns | =1 |   | 	number of shots 
int     | nt | = |   | 	number of time steps 
int     | sxbeg | = |   | 	x-begining index of sources, starting from 0 
int     | szbeg | = |   | 	z-begining index of sources, starting from 0 
[DIRECTORY]
user/pyang
