NAME

Stretch - Generic stretch routine


SYNOPSIS

Stretch rule=nmo conj=0 inv=0 [vel=1.5] [velfile=vel.H] < in.H > out.H


INPUT PARAMETERS

conj - integer
      [0]  - operator itself
      1  - conjugate operator
inv - integer
      [0] -  operator itself
      1  - pseudo inverse
rule - character string
      -NMO, linear interp. and tabulation
       nmo0  -NMO, nearest neigbor, integer arithmetic.
       nmo1  -NMO, nearest neighbor interpolation.
       nmo2  -NMO, linear interpolation
       unmo  -NMO, pseudoUnitary. (conjugate is pseudoinverse)
       rownmo-NMO by linear interp,
       inverse divides out the row sum.
       offset-trace resampling on 2-axis along hyperbolic curves.
       linear on 2-axis, near neighbor on 1-axis.
       inverse approximated by conjugate.
       radial - radial trace without nmo.
       radnmo - radial trace, u=x/tau, nearest
       neighbor, does NMO too.
       inverse not exact when v=v(tau)
       stolt  - stolt stretch, give n1= on command line.
       lmo1  -LMO, nearest neighbor interpolation.
       lmo2  -LMO, linear interpolation
t_of_tau - file
      somefile.H  overrides vel.H
vel - real
      [1.5]   velocity
velfile - file
      velocity file, supersedes constant velocity.  Can be 2-D.
      If 2-D, n2 of velocity file must equal n3 of data.  Otherwise
      the first velocity function is used for all n3.  Consistency
      of o2,d2 of velocity file with o3,d3 of data is NOT checked.
n1,n2 - integer
      standard seplib parameters (from history)
o1,o2 - real
      standard seplib parameters (from history)
d1,d2 - real
      standard seplib parameters (from history)
n1 - integer
      (from velfile) length of velocity trace


DESCRIPTION

  Stretch transformations with:   2       2     2    2
                                 t  =  tau  +  x  / v(tau)


COMMENTS

  rule=radnmo not yet passing dot product test.
  rule=stolt not yet implemented
  rule=lmo not well tested


CATEGORY

seis/velan