Data Set Overview
    =================
      Using OASIS at cassegrain focus of the 188-cm telescope of the
      Okayama Astrophysical Observatory, infrared images centered at 2.35
      micron were taken of the crash of fragment K from the Shoemaker-Levy
      9 comet into Jupiter.  The data consist of 160 images with detached
      labels and documentation.
 
 
    Background
    ==========
      1500 frames of near-infrared images were taken from 15 - 24 July.
      Pixel size is 256x256, data size is 270KB for one frame. Total size
      of all data is about 400MB (but they include less valuable data)
 
      OASIS observed impacts of fragments C, D, K and N.
 
                  wavelength  number of
                  (micron)    frames
      C impact      2.35       360 (C-plume was saturated in 30 frames)
      D impact    2.35/1.70    240 (170/2.35, 70/1.70; no detect for 1.70)
      K impact      2.35       160 (Total size of the K impact is 43MB)
      N impact      2.17       400 (but no detect)
 
      There are additional data in which ten frames taken during 3-5
      minutes were combined to form a better image.  A summary of data is
      given below.
 
       wavelength/micron    number of frames
       1.70 (methane band)    30
       2.17 (hydrogen band)  130
       2.35 (methane band)   140
       1.50 (ammonia band)    15
       others (continuum)     17
 
      The impact of fragment K was predicted at 10h18m UT, July 19, 1994.
      A filter (center wavelength of 2.35 micron (FWHM 0.05 micron)) was
      used to take images continuously. In each frame, Jupiter and two
      Galilean satellites, Io (left) and Ganymede (right) were seen. Io
      was used as a flux calibrator. Flux from Io was estimated at
      7.8x10^-12 W m^-2 micron^-1 These observations caught two
      precursors: the main event and the shoulder of the K impact. Two ND
      filters were used, whose transparencies are 10% and 2%, to prevent
      the OASIS from saturation due to the brighter main event.
 
      For details about the observations, see the following papers:
 
      Watanabe et al., Publ. Astron. Soc. Japan, 47,L21-L24 and Plate 5
      (1995) [WATANABEETAL1995]
 
      Takeuchi et al., Geophys. Res. Letters, 22, 1581-1584 (1995)
      [TAKEUCHIETAL1995]
 
 
    Processing
    ==========
      For the images taken by Okayama at 1994 July, the top of the image
      was south.  So, IRAF was used to rotate the images by 180 degrees
      around the centers of the images resulting in associated keywords
      such as WSCDIM.  Each image from the fragment K set was bias
      subtracted, flat fielded and corrected for bad pixels. The top of
      each frame is north.
 
      In addition, IRAF was used to correct for cosmic rays (see CRCOR
      which is a comment on cosmic ray work).
 
 
    Data structure
    ==============
      The data were supplied in FITS form.
 
 
    Ancillary Data
    ==============
      None
 
 
    Software
    ========
      None
 
 
    Media/Format
    ============
      The data were supplied on 8 mm tape.

Confidence Level Overview
    =========================
      The 160 images were inspected at the SBN and corrections made to the
      data were recorded in the PDS labels.
 
 
    Data Coverage and Quality
    =========================
      Only fragment K data has been included in this archive.
 
 
    Limitations
    ===========
      The accuracy of the starting time is +/-1sec, but the accuracy of
      the integrating time is even better, +/-0.005sec.