IMGRECON(1)

NAME

     strategy module to  reconstruct  images  from  MDI  data  in
     telemetry list format

SYNOPSIS

     imgrecon in= in_ds out= out_ds [-rvm]

DESCRIPTION

     imgrecon reconstructs tabular data produced by MDI into  the
     appropriate two-dimensional image format, using the MDI Data
     Product Code (DPC) to determine the correct  reconstruction.
     With  the  -r flag it converts two-dimensional images to the
     tabular format appropriate to the DPC.

     Many data products from MDI are in tabular (one-dimensional)
     form  for  the sake of compression: in particular, most com-
     plete and binned full-disc  images  are  cropped  to  remove
     meaningless  data  from  beyond the solar limb.  The tabular
     format  is  preserved  by  definition  through  level-0  and
     level-1  processing  (decommutation  and calibration of data
     products), which does not involve any remapping of the data.
     imgrecon  can  be  used  to produce a two-dimensional image,
     with fill values where  the  data  were  cropped,  from  the
     information  about  on-board  processing  unique to the DPC.
     The DPC is an 8-character string, the hexadecimal  represen-
     tation  of  a 4-byte word, which appears in every valid data
     header.

     imgrecon expects FITS files on input and produces FITS files
     on  output.   With  the  -m flag it produces a merged output
     file.  With the -v flag it produces verbose output.

ARGUMENTS

     in=  The input dataset name.  If the input dataset  name  is
          not  specified  explicitly,  the output dataset name is
          used for input.

     out= The output dataset name.

     dpc= The Data Product Code to be used.  By default, the  DPC
          in the input data set is used.  It can be overridden in
          case it is missing or incorrect.

     fill=integer        The FILL value to  be  used  in  missing
                         pixels (default -32768).

EXAMPLES

     imgrecon in= /tmp0/maggrams/[0-3] out= /scr0/tmp/
     will take files 0000.fits  through  0003.fits  on  directory
     /tmp0/maggrams,  which are assumed to contain MDI cropped or
     other list-ordered data products, and produce  2-dimensional
     reconstructed  FITS  image files 0000.fits through 0003.fits
     on directory /scr0/tmp.

FILES

     /home/soi/CM/tables/cropXXXX.fits
     /home/soi/CM/tables/limbXXXX.fits
     /home/soi/CM/tables/irbinXXXX.fits
     /home/soi/CM/tables/rwbinXXXX.fits
     /home/soi/CM/tables/vwbinXXXX.fits

SEE ALSO

     MDI_image (3)

DIAGNOSTICS

     On a return status of non_zero, soi_errno and/or  the  error
     stack should be inspected for the cause of failure.

BUGS

     Proper image  reconstruction  is  necessarily  table-driven.
     Without  the  presence  of  the appropriate external tables,
     this and comparable modules will not function.

     When reconstruction (or more likely deconstruction) is  per-
     formed with a user-supplied DPC and the operation is done in
     place (in = out, the default), the new DPC is not  correctly
     written into the headers or the record.rdb file.

     imgrecon does not work for data  products  corresponding  to
     certain vector-weighted bin lists (6001, 6002, 6004).  Until
     it is fixed to work for those, use  either  old_imgrecon  or
     make_list_image,  both of which use unnecessarily arcane and
     inefficient methods of reconstruction, but do work, at least
     for properly tabulated data products.

     Error reporting by the main module  is  minimal.   When  the
     image cannot be reconstructed for any reason, the input data
     are merely copied to the output.

     There are other undocumented modules for  accomplishing  the
     same    purpose:     old_imgrecon,    make_list_image,   and
     imgrecon_vds.  There is no guarantee  that  they  will  work
     when imgrecon fails.

     Use of the optional FILL value has not been well-tested;  it
     may  result  in  different FILL values being used for pixels
     missing from the original data set  and  those  supplied  to
     fill out empty areas in the reconstructed image.

AUTHOR

     Rick Bogart

HISTORY

     1998-03-06      SOI Version 2.9