%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      definemos.hlq
%.AUTHOR     JDP, IPG/ESO
%.KEYWORDS   MIDAS, help files, DEFINE/MOS
%.PURPOSE    On-line help file for the command: DEFINE/MOS
%.VERSION    1.0  18-DEC-1986 : Creation, JDP
%----------------------------------------------------------------
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SECTION./MOS
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DEFINE/MOS					10-DEC-1993 SM
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DEFINE/MOS [object] [mos] [windows] [thresh] [wind] [xbin] [centmet]
	searches for objects and defines sky regions
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Purpose:   
	  Searches for objects and defines sky regions
\up\sy
Syntax:		
	  DEFINE/MOS [object] [mos] [windows] [thresh] [wind] [xbin] [centmet]
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	  object = object frame
              Session keyword: OBJECT
              Default: none
	  mos = table with slitlets' positions 
              Session keyword: MOS
              Default: mos
	  windows = output table with objects' and sky positions
              Session keyword: WINDOWS
              Default: window
	  thresh = detection threshold for objects (absolut > 0, relative < 0)
              Session keyword: THRESH
              Default: -0.04
	  wind = searching window for object detection and gaussian fit
              Session keyword: WIND
              Default: 5
	  xbin = number of lines to be averaged before search
              Session keyword: XBIN
              Default: 20
	  scanpos = position where the scan along the spatial axis shall \\
              be taken. 
              Session keyword: SCAN_POS
              Default: 0 (= center of frame)
	  plotopt = plot option\\
              0 = no plot (Default) \\
	      1 = two-dimensional display only \\
	      2 = graphical display only \\
	      3 = two-dimensional and graphical display \\
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See also:
          DEFINE/WINDOW
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Note:       
	  Objects are centered with a gaussian fit. The limits of the 
	  objects are taken at a distance from the center of the object 	
          where the gaussian fit has an intensity of a given fraction of the 
          central intensity (stored in the keyword INT_LIM, default: 0.001). 

	  The sky region is determined up to 3 pixels away of these 
	  limits. Therefore the threshold should be chosen in a way to 
	  make sure that everything that should NOT be included in the 
	  sky fit region is detected! 

                         !! NOT YET IMPLEMENTED !!
	  By comparing the objects found to the coordinates from the 
	  MOS image the wanted objects will be identified and marked.
	  For images from other instruments the user will be asked to 
	  identify the objects that should be extracted later on.            
                         !! NOT YET IMPLEMENTED !!

	  After the automatic identification of sky and object regions
  	  the user may change the limits manually. It is possible to 
	  add/delete objects/sky region or to change the limits of these
	  regions. However, if you want to add/change sky in a way that
	  it overlaps with an object you have to delete this object 
	  before!
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Examples:
\ex
	  DEFINE/MOS rebobj mos windows -0.03 5 200 6000 1
          Searches the frame rebobj.bdf within the slitlet limits defined by
          mos.tbl and stores object/sky limits in windows.tbl. Detects any
          object that is 3% above local background, using a search window
          of 5 pixels. The one-dimensional trace, that is searched, is
          created by averaging 200 pixels around the coordinate 6000 (100
          on each side). The results are shown in the two-dimensional display
          only.
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