Instrument Host Overview
    ========================
      The ground-based observations for the SL9 campaign were supplied by
      groups using many supporting astronomical observatories.  Listed
      below are the separate telescopes with appropriate observational
      parameters for which data were submitted.
 
      European Southern Observatory
      New Technology Telescope
      Nasmyth focus, image derotator, multiple feed
      SUSI (imager) 0.13 arcsec in the focal plane of the NTT
 
      SUSI imaging capabilities complement well those of EMMI on the other
      focus.  While EMMI provides, besides the various spectroscopic
      options, large-field capabilities (up to 10 x 10 arcmin with a
      2048**2 CCD), imaging at SUSI is limited to a 2.2 x 2.2 arcmin
      field  during periods of excellent seeing.  The IRSPEC at the NTT
      was upgraded at the beginning of the 1991 season by replacing its
      linear detector with a 2D SBRC 58x62 pixel InSb array which exhibits
      good cosmetic quality and high quantum efficiency from 1 to 5 micron
      with resolving powers of 1000 to 5000 for a nominal slit length of 2
      arcmin.  The instrument is attached permamently to one of the
      Nasmyth foci of the NTT.