Data Set Overview  :   This dataset includes the Galileo Orbiter Solid State Imaging data on the  asteroid 243 Ida. The raw data have already been archived in PDS with the  data set name 'Galileo Imaging (SSI) Asteroid, Earth and Moon Experiment  Data Records' and can be found by searching on the data set identification  'GO-A/E-SSI-2-REDR-V1.0'. Only those images in which Ida actually appears  have been included here. Images in both FITS and ISIS Cube format are  provided.    Processing of the ISIS Cube Format Files  :   The raw images were converted from VICAR format to FITS format using the  image reduction package IRAF. The image prefix tables, telemetry tables,  and bad data value headers were removed from the raw images. All relevant  label keywords describing the image have been retained in the raw image  labels.   The images in this archive were converted from FITS format to ISIS cube  format using GLLSSI2ISIS, and radiometrically calibrated using GLLSSICAL.  GLLSSICAL was the tool provided in the original, raw data delivery for  calibration of Galileo SSI images. GLLSSI2ISIS inputs were the raw image  file name and the output image file name for the ISIS format image.  GLLSSICAL inputs were image file name in the ISIS format created by  GLLSSI2ISIS, units : IOF, scale:1. The GLLSSICAL output was the file name  for the radiometrically calibrated image in ISIS cube format.   Description of the ISIS software can be found in:   Anderson, J.A., 2008. ISIS camera model design, 39th LPSC (Houston), p.  Abstract #2159, Lunar and Planetary Institute.   Anderson, J.A., Sides, S.C., Sotesz, D.L., Sucharski, T.L., Beker, K.J.,  2004. Modernization of the integrated software for imagers and  spectrometers, 35th LPSC (Houston), p. Abstract #2039, Lunar and Planetary  Institute.    Processing of the FITS Format Files  :   The raw images were converted from VICAR format to FITS format using the  image reduction package IRAF. The image prefix tables, telemetry tables,  and bad data value headers were removed from the raw images. All relevant  label keywords describing the image have been retained in the raw image  labels.   The images in this archive were converted from FITS format to ISIS cube  format using GLLSSI2ISIS, and radiometrically calibrated using GLLSSICAL.  GLLSSICAL was the tool provided in the original, raw data delivery for  calibration of Galileo SSI images. GLLSSI2ISIS inputs were the raw image  file name and the output image file name for the ISIS format image.  GLLSSICAL inputs were image file name in the ISIS format created by  GLLSSI2ISIS, units : IOF, scale:1. The GLLSSICAL output was the file name  for the radiometrically calibrated image in ISIS cube format. The  radiometrically calibrated ISIS cube format images were converted to FITS  format using the ISIS routine ISIS2FITS. ISIS2FITS inputs were the  radiometrically calibrated image file name (in ISIS cube format),  bittype:32, minpercent:0.5, maxpercent:99.5, info:Nominal (nominal fits  header). The ISIS2FITS output was the radiometrically calibrated image in  FITS format.   Description of the ISIS software can be found in:   Anderson, J.A., Sides, S.C., Sotesz, D.L., Sucharski, T.L., Beker, K.J.,  2004. Modernization of the integrated software for imagers and  spectrometers, 35th LPSC (Houston), p. Abstract #2039, Lunar and Planetary  Institute.   Radiometric Calibration Description  :   The GLLSSICAL program performs the following processing steps on each pixel: 1. The radiometric correction is applied:  e : z(d - dc)  where:  z is retrieved from the Radiometric File.  d is the DN.  dc is retrieved from the Dark-Current File.   2. The output pixel is scaled to I/F using the following equation:  S1 K  r : e * -------- * --- (D/5.2)2  A1(t-to) Ko   where:  S1 : filter-dependent conversion factor from ft-Lamberts to I/F  units for a reference distance of 5.2 AU from the Sun.   A1 : output picture scale factor.   t : commanded exposure time of the input image(msec).   to : line-dependent shutter offset.   K : system gain constant for the gain-state of the image.   Ko : system gain constant for the calibration file gain-state.   D : target distance from the Sun (in AU).   The output DN is usually in the range of 0.0 to 1.0. If the uneven bit  weighting correction is enabled, the input DN values (d) will be corrected  for uneven-bit-weighting due to the ADC. If the input dark-current file is  in byte format (i.e. an individual dark-current frame), then the correction  will be applied to the dark-current as well. The current correction table  was supplied by Herb Breneman, 2 Mar 89, and is based on 1975 calibration  data. This application outputs LRS for any negative I/F values that are  encountered.    Data  :   The data are included in a series of files with filenames of the form  *rcal_XXX.FIT, where * denotes the spacecraft clock start count, rcal  denotes the image has been radiometrically calibrated, and XXX denotes the  filter name where:   Filter Name XXX  CLEAR clr  RED red  GREEN gre  VIOLET vio  IR-7560 ir7  IR-8890 ir8  IR-9680 ir9   The filename of the original, raw files were the last four digits of the  spacecraft clock start count.   The general table, color-set_id.tab, denotes which images were acquired at  similar viewing conditions but in separate filters, thus constituting a  color image set. The table includes image file name, filter name, and a  designator for which color set the image belongs. Images with the same  designator value (A-F) belong to the same color image set.   Filter response curves taken from Klaasen et al. 1997 are included in the  document directory.   Both FITS and CUBE files are 2.6MB in size, giving 169MB each for the FITS  and CUBE file subdirectories. The corresponding image labels are 4 KB each,  giving 260KB each for the label subdirectories.   K.P. Klaasen, M.J.S. Belton, H.H. Brenenman, A.S. McEwen, M.E. Davies, R.J.  Sullivan, C.R. Clark, G. Neukum, C.M. Heffernan, A.P. Harch, J.M. Kaufman,  W.J. Merline, L.R. Gaddis, W.F. Cunningham, P. Helfenstein, T.R. Colvin.  Inflight performance characteristics, calibration, and utilization of the  Galileo solid-state imaging camera, Opt. Eng.36(11) 3001-3027 (November  1997).

Confidence Level Overview  :  This dataset includes only those Galileo SSI images in which 243 Ida  actually appears. No viable camera kernels for the time frame in which the Ida images were acquired were included in the original PDS archive. These  kernels are used by GLLSSICAL to convert raw values to reflectance. A work around was used in which GLLSSICAL was set to assume nadir pointing for  all images. This produces negligible errors in radiometric values, but  disables any calculations of viewing and illumination conditions.   Several images include saturated lines (rows of pixels) and pixels. These  were present in the original raw images and not removed in the radiometric calibration process. Only those pixels on the asteroid contain meaningful  data, though some saturated pixels may be found on the asteroid. No  extrapolations were made to remove erroneous data so that future users can determine which were viable pixels and which were not.