NAME

     recshift  - insert record  constant  time  shifts  to  trace
     header with interpolation between control points. Input con-
     trol via flat file, xsd pick file, xsd header value at  pick
     file. Use rest to do the shift operation.

SYNOPSIS

     recshift [ -Nntap ] [ -Ootap ] [ -Ppfile ] [  -siisamp  ]  [
     -jiseg  ]  [  -rwirw  ]  [  -swisw  ]  [ -dit0 ] [ -rire ] [
     -sshifts ] [ -xsdheader ] [ -xsd ] [ -flat ] [  [  -D3  ]  [
     -liminlimin  ] [ -limaxlimax ] [ -dimindimin ] [ -dimaxdimax
     ] ] [ -V ] [ -? or -h ]

DESCRIPTION

     recshift puts record  constant  time  shifts  into  a  trace
     header mnemonic of your choice for later application by pro-
     gram rest. The input data can be 2D or 3D data.  The  shifts
     may be supplied in the form of a 2-col flat file, or an  xsd
     pick file, or an  xsd  header, or an exported Landmark  hor-
     izon  file  with  each  line containing LI, DI, and time, or
     (for 2D data only) input as (record, time) pairs on the com-
     mand line.

     The picks or record-time pairs will be generated from a  CDP
     stacked section (in the case of CDP input records) or from a
     near trace stack (in the case of shot records. The  3D  case
     is  essentially  CDP  driven and picks will be made on a few
     inlines or  crosslines  taken  from  a  CDP  stacked  volume
     although the input data may be in any sort order.

     For 3D data using xsd picks (either picks  or  header  picks
     are  acceptable)  or a flat file, the picks will normally be
     made on a few inlines or crosslines from a  stacked  volume.
     The  pick file then must contain the LI & DI number from the
     stacked headers. In addition the stacked volume should  have
     the min & max LI & DI (MnLnIn, MxLnIn, MnDpIn, MxDpIn) prop-
     erly filled out in the line header (these can  be  overrrid-
     den).

     It is very important when saving the   xsd  picks  that  the
     proper  sample  unit  and  offset be specified.  This can be
     corrected later on with sample interval overrides  and  time
     scale  factors but it gets harder to undo mistakes early on.
     When using a sample  interval  of  microseconds  you  should
     choose  a  longer  header  word  to  store the times:  it is
     recommended for instance that SGRDat be a candidate.

      recshift  gets both its data and its parameters  from  com-
     mand line arguments. These arguments specify the input, out-
     put, the  xsd  pick file or header value  at  pick  location
     file,  the sample interval multiplier, the segment number in
     the pick file to  use,  the  index  reference  trace  header
     mnemonic,  the  shift  time trace header mnemonic, the datum
     time, and optionally (record, time shift) pairs.

  Command line arguments
     -N ntap
          Enter the input data set name or file immediately after
          typing -N unless the input is from a pipe in which case
          the -N entry must be omitted. This  input  file  should
          include the complete path name if the file resides in a
          different directory.  Example -N/b/vsp/dummy tells  the
          program to look for file 'dummy' in directory '/b/vsp'.

     -O otap
          Enter the output data  set  name  or  file  immediately
          after typing -O.  This output file is not required when
          piping the output to another process.  The output  data
          set also requires the full path name (see above).

     -P pfile
          Enter the optional xsd  pick  file,  xsd  trace  header
          file,  or  2-col  format flat file, with values at pick
          locations defined by record control  points  and  their
          times  to  be applied as shifts.  In the case of eitehr
          xsd formats these picks should be made from  a  stacked
          section  and  can  be  applied  to stacked or unstacked
          data. For 3D applications the picks  will  normally  be
          made  on  a  few  inlines  or crosslines from a stacked
          volume. The pick file then must contain  the  LI  &  DI
          numb  er from the stacked headers since this is used to
          drive the  interpolation.  In  addi  tion  the  stacked
          volume  should  have  the  min  &  max LI & DI (MnLnIn,
          MxLnIn, MnDpIn,
           MxDpIn) properly filled out in the line header  (these
          can be overrridden).

     -xsd Enter the command line argument  -xsd  if the  attached
          pickfile is in standard xsd pickfile format.

     -xsdheader
          Enter the command line  argument   -xsdheader   if  the
          attached  pickfile  is in xsd header value file format.
          If not present and a pickfile is attached it is assumed
          to be in standard xsd pickfile format.

     -flat
          Enter the command line argument  -flat  if the attached
          pickfile  is  in  2-column  flat file format where each
          line contains a record number followed by a shift time.

     -j iseg
          For the pick file option enter the  segment  number  to
          use (for 2D data only).  Default = 1

     -si isamp
          Enter the pick time  scale  factor.  If  you  use  this
          option  to  get  better  fidelity in your picks [say by
          multiplying milliseconds by 1000.] be  sure  to  convey
          this   information  to   rest   prior  to  application.
          Default = 1.

     -d it0
          Enter a time datum if datuming is desired. Be  sure  to
          use  the   same  units as the pick file or command line
          time entries.  Default = 0.

     -sw stawrd
          Enter the trace header menmonic in  which  to  put  the
          shifts.  Default = StaCor.  Note: this is a very useful
          entry if you want to shift records around and  yet  not
          trash  the original statics; it is also useful to store
          very long times that you might get  from  picking  data
          sampled in microseconds.

     -rw recwrd
          Enter the trace header menmonic which to reference  the
          record  index in the (record, time) pairs to. Default =
          RecNum

     -r ire
          Enter the sequential record number control  point.   No
          default.   This  and  the corresponding time input used
          only if an  xsd  pick file is not attached.

     -t shifts
          Enter the time shift (ms) to be applied at this  record
          number.   No  default.  These pairs (-r[] and -t[]) can
          be repeated as many times  as  necessary  to  span  the
          input data.

     Note: shifts will be linearly interpolated  between  control
     points and  NO  extrapolation will be done.

     -D3  Enter the command  line  argument  '-D3'  for  3D  data
          application.  You  can  input horizon information using
          the three types of pick files keyed on LI and  DI.  For
          XY  driven  horizon files of more options for smoothing
          nd fitting of horizon files use tim2hed3d.

     -limin limin
          Enter the minimum LI override. If zero then MnLnIn from
          the input line header will
           be used.

     -limax limax
          Enter the maximum LI override. If zero then MxLnIn from
          the input line header will
           be used.

     -dimin dimin
          Enter the minimum DI override. If zero then MnDpIn from
          the input line header will
           be used.

     -dimax dimax
          Enter the maximum DI override. If zero then MxDpIn from
          the input line header will
           be used.

     -V   Enter the command line argument '-V' to get  additional
          printout.

     -? or -h
          Enter the command line argument  '-?'  or  -h   to  get
          online  help.  The  program  terminates  after the help
          screen is printed.

BUGS

     For 3D data picks must be made on a stacked volume that  has
     either proper LI & DIs or proper SrRcMX & SrRcMY midpoint XY
     values in the trace headers.

SEE ALSO

     rest

AUTHOR

     Paul Gutowski