*xrfits, mperfits* - FITS Arrays on tape to IRAF (.imh) files

After the `allocate mtn' command (Reading FITS files from tape)

  
  cl> xray
  xr> xdataio
  xd> xrfits mtn 3 visitor_a  # load tape file 3 and name it visitor_a.imh
  xd> xrfits mtn 1-10 visitor         # load files 1 to 10 in visitor_0001
                                                        # to visitor_a.imh
  frame visitor.0001 average frame [300,500]      # One line like this per 
                                                             # file loaded 
                        # .headers will be loaded in the working directory
          # *.pix files (the images) will be loaded in the image directory
  xd> xrfits mtn 11,13-14 visitor            # A different loading command

If you have image arrays written by MIDAS, use mperfits:

 xd> mperfits mtn 1-3 images # Convert the first three files on tape device mtn

When you have finished loading your files,

  xd> rewind mtn
  xd> deallocate mtn                             # IRAF release of tape drive


               To dismount the tapes at SAO:

                  cfa250: rlsdev mtn      #release the tape drive
                  cfa250: logout                  #logout of reel

N.B.#1: File numbers in a single xrfits call must be in increasing order.

N.B.#2: To list the names of files 1 to 10 without loading the files, use rfits in dataio.

  da> rfits mtn 1_10 make_im=no

N.B.#3: Dimensions of FITS Arrays.

There is sometimes trouble with dimensionality of FITS images. IRAF likes images to have 2 dimensions. To use imlintran, etc. if the input image thinks it has dimensions 3,4,..., it is necessary to copy the image and to modify the header. To find out the dimensionality of an image, type

  im> imhead velalow         # gives short header for the image ``velalow''
  velalow [512:512:1][real]:EINSTEIN XRAY DATA   # this response indicates
                                                            # 3 dimensions

or this response might be,

  velalow [512:512][real]:EINSTEIN XRAY DATA

which indicates 2 dimensions, a satisfactory input for iraf tasks.

If more than 2 dimensions, type

  im> imcopy velalow[1:512,1:512] velalow  # will make 2 dimensional image

The parameter WCSDIM in the header must also be changed

  
  im> hedit
       images: velalow
       field: WCSDIM
       value(3): 2
       WCSDIM 3>2: <cr>
       update velalow (yes): <cr>

  im>