#restart=1
nw_tot=3
npad_x=0 
npad_y=0 
maxang=60. 
npad_mx=0 12  
npad_hx=0 10 
npad_my=0 12  
npad_hy=0 10 
nzb=1 
wem_type=CAM
nz=2 300
oz=0
dz=10
verb=y
pverb=2
#  Number of CMP in X (axis 1 of D,R and S)
amx_n=670
#  Sampling of CMP in X
amx_d=20
#  First CMP  X location 
amx_o=0
#  Number of CMP in X (axis 2 of D,R and S)
amy_n=200
#  Sampling of CMP in Y
amy_d=20
#  First CMP  Y location 
amy_o=1600
#  Number of offsets in X (axis 3 of D and possibly R  )
ahx_n=143
#  Sampling of offsets in X
ahx_d=25
#  First offset  X location 
ahx_o=-1775
#  Number of offsets in Y (axis 4 of D and possibly R)
ahy_n=1
#  Sampling of offset in Y
ahy_d=40
#  First offset  Y location 
ahy_o=0
#  Number of depth steps
az__n=2 300
#  Sampling of depths
az__d=10
#  First depth of model
az__o=0
#  Whether or not make the image real
image_real=1
#  Number of frequencies
aw__n=3
#  Sampling of frequencies
aw__d=0.166667
#  First frequency of data
#aw__o=0
# [1] number of velocities for each depth step 
nfk=4
#Number of Z steps to do in memory
nzs=1
#Number of W to hold in memory
nws=1
#[.false.] whether or not S is velocity
velocity=1
#
#=back
#
#=head1 PH GATHERS
#
#=over 4
# 
#=item pCIG (logical)
#
# [.false.] whether (.true.) or not (.false.) to create PH gathers
#
#=item cigs (logical)
#
# [.true.] whether (.true.) or not (.false.) to use Marie's method to create 
# cigs
#
#=item apx__n (integer) 
#
#  Number of PH in X (axis 3 of R)
#
#=item apx_d (integer) 
#
#  Sampling of PH in X
#
#=item apx_o (integer)
#
#  First PH X location 
#
#=item apy__n (integer)
#
#  Number of PH in Y (axis 4 of R)
#
#=item apy_d (integer) 
#
#  Sampling of PH in Y
#
#=item apy_o (integer)
#
#  First PH  Y location 
#
#=item pgiceps (float)
#
#  [.1] Epsilon parameter for Phgather construction
#
#=item vsalt (float)
#
#  [0.] Salt velocity 
#
#=back
#
#=head1 MEMORY MANAGEMET
#
#=over 4
#
#=back
#
#=head1 DESCRIPTION
#
# Perform split step phase shift migration/modeling
#
#
#
#
#=head1 COMMENTS
#
#=over 4
#
#=item  anx_n,ahx_d,ahx_o and axis 1 of D and R  must be the same
#
#=item  any_n,ahy_d,ahy_o and axis 2 of D and R  must be the same
#
#=item Slowness must contain entire  span of X and Y
#
#=item  az__n,az__d,az__o , axis 3 of S and axis 5 of R  must be the same
#
#=item When doing ph gathers apx_n = ahx_n = n3 of D
#
#=item When doing ph gathers apy_n = ahy_n = n4 of D
#
#=item When doing offset gathers  ahx_n,ahx_d,ahx_o = axis 3 of D and R
#
#=item When doing offset gathers  ahy_n,ahy_d,ahy_o = axis 4 of D and R
#
#=item nzs must be a multiple of az__n
#
#=item nws*nmpi_threads*nomp_threads must be a multiple of aw__n 
#
#=cut