Program sfmpicfftrtm | Lowrank decomposition for 3-D isotropic wave propagation. 
[SYNOPSIS]
sfmpicfftrtm verb=false migr=false roll=false dabc=false snap=false mute=false sill=false nb=0 cb=1.0 nbell=1 jsnap=100 jump=1 seed=time(NULL npk=20 eps=1.e-4 media=0 taper=0 thres=1 sou_t0=0. vel_w=1500. revolve_snaps=64 info=0 sht_set=0 sht_num=sht_num_total
[PARAMETERS]
        | cb | =1.0 |   | 	abc strength
        | dabc | =false |   | 	absorbing boundary
        | eps | =1.e-4 |   | 	tolerance/accuracy
        | info | =0 |   | 	verbosity of output info about revolve
        | jsnap | =100 |   | 	snapshot interval
        | jump | =1 |   | 	subsampling rate for lowrank decomposition
        | media | =0 |   | 	media: 0-> iso, 1-> tti
        | migr | =false |   | 	adjoint(migration) flag
        | mute | =false |   | 	mute first arrival (modeling or imaging)
        | nb | =0 |   | 	abc width
        | nbell | =1 |   | 	source position z
        | npk | =20 |   | 	maximum rank
        | revolve_snaps | =64 |   | 	maximum num of snapshots allowed to be saved
        | roll | =false |   | 	rolling v.s. fixed-spread acquisition geometry
        | seed | =time(NULL |   | 	
        | sht_num | =sht_num_total |   | 	shot number to process
        | sht_set | =0 |   | 	starting shot index
        | sill | =false |   | 	source illumination for rtm
        | snap | =false |   | 	output wavefield snapshots
        | sou_t0 | =0. |   | 	source delay
        | taper | =0 |   | 	tapering interval for tti
        | thres | =1 |   | 	tapering threshold for tti
        | vel_w | =1500. |   | 	water velocity
        | verb | =false |   | 	verbosity
[DIRECTORY]
user/jsun
