NAME

     transp  - module to transpose a seismic record

SYNOPSIS

     transp [ -Nntap ] [ -Ootap ] [ -sist ] [ -eiend ] [ -ntntr ]
     [ -rsnrst ] [ -renred ] [ -V ] [ -? ]

DESCRIPTION

     transp treats each selected record as a matrix and  computes
     the  transpose. Note that two successive uses of transp will
     result in the original data being regenerated. This  program
     is  particularly  useful  when temporal 1-d trace processing
     programs are applied to the spatial domain or  when  turning
     aliased  events into unaliased arrivals for further process-
     ing.

     Trace header information is preserved by mapping  the  input
     headers  onto  the  output  headers.  Since the trace number
     axis now becomes the sample axis (and vice-versa) the  first
     ntrc  traces  of  the  transposed  output (where ntrc is the
     input number of traces/record)  will  contain  the  original
     input  trace  headers;  the rest of the output trace headers
     will contain the last valid trace header. Obviously a  weak-
     ness of this is that if the input number of traces/record is
     greater than the input number of samples/trace header infor-
     mation  will  be  lost and you will have to do a header swap
     with the reverse transposed data set and the original  input
     data  set.  However if the number of samples is greater than
     the number of traces a reverse transpose  will  restore  all
     the original headers.

     Special care is taken with dead  traces.   This  is  because
     after  transposing  any  process that is run which detects a
     dead trace and for whatever reason zeros out that trace will
     result  in  a  horizontal dead zone after reverse transposi-
     tion. Nearly every program in USP uses 30000 static  as  the
     dead trace flag so that when the forward transpose detects a
     30000 in the static word StaCor it resets it to -30000. This
     will  not  trigger  the  dead trace detects in any other USP
     program. Upon reverse transposition any static word that has
     a -30000 is reset to 30000.

     transp gets both its data and its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     the start and end times, the  start  and  end  records,  the
     number  of  traces within a record, and verbose printout, if
     desired.

  Command line arguments
     -N ntap
          Enter the input data set name or file immediately after
          typing  -N  (can  be  a  pipe).  This input file should
          include the complete path name if the file resides in a
          different  directory.  Example  -N/vsp/dummy  tells the
          program to look for file 'dummy' in directory '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).

     -s ist
          -e iend Enter the start time and end time  in  ms.  The
          defaults are the start and end of the trace.

     -nt ntr
          Enter the number of traces to  transpose  if  different
          from the input traces/record.

     -rs nrst
          Enter start record number.  Default value is the  first
          record.

     -re nred
          Enter end record number.  Default value is last record.

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

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

BUGS

     Special handling will be  needed  if  the  input  number  of
     traces/record  is  greater than the number of samples/trace.
     In these cases the final reverse transposed result will have
     to  have  headers  swapped  from the input data to the first
     transpose (see hdrswap).

AUTHOR

     Paul Gutowski, ATTC, x3146, pgutowski@trc.amoco.com

COPYRIGHT

     copyright 2001, Amoco Production Company
               All Rights Reserved
          an affiliate of BP America Inc.