PDS_VERSION_ID                  = PDS3
RECORD_TYPE                     = FIXED_LENGTH
RECORD_BYTES                    = 76
FILE_RECORDS                    = 131
^SERIES                         = "PPSCALIB.TAB"

DATA_SET_ID                     = "VG2-SR/UR/NR-PPS-2/4-OCC-V1.0"
RING_OBSERVATION_ID             = "S/OCC/VG2/PPS/1981-08-25/DELTA_SCO"
PRODUCT_ID                      = "PPSCALIB.TAB"
PRODUCT_TYPE                    = CALIBRATION_MODEL
PRODUCT_CREATION_TIME           = 2000-06-01T16:00:00
SOURCE_PRODUCT_ID               = "PS1C01.TAB"

SPACECRAFT_NAME                 = "VOYAGER 2"
SPACECRAFT_ID                   = VG2
INSTRUMENT_NAME                 = "PHOTOPOLARIMETER SUBSYSTEM"
INSTRUMENT_ID                   = PPS
TARGET_NAME                     = "S RINGS"
START_TIME                      = 1981-08-25T23:46:47.426
STOP_TIME                       = 1981-08-26T01:56:47.418
SPACECRAFT_CLOCK_START_COUNT    = "44001:05:401" /*Voyager FDS count*/
SPACECRAFT_CLOCK_STOP_COUNT     = "44003:48:001"

FEATURE_NAME                    = "RING SYSTEM"
RING_OCCULTATION_DIRECTION      = EGRESS
STAR_NAME                       = "DELTA SCO"
NOISE_TYPE                      = POISSON
INCIDENCE_ANGLE                 = 61.314598
                                          /* traditionally, mu=0.48 */

OBJECT                          = SERIES
  NAME                          = OCCULTATION_CALIBRATION
  INTERCHANGE_FORMAT            = ASCII
  ROWS                          = 131
  COLUMNS                       = 8
  ROW_BYTES                     = 76
  SAMPLING_PARAMETER_NAME       = RECORD_INDEX
  SAMPLING_PARAMETER_UNIT       = 'N/A'
  MINIMUM_SAMPLING_PARAMETER    = -10
  MAXIMUM_SAMPLING_PARAMETER    = 1290
  SAMPLING_PARAMETER_INTERVAL   = 10
  DESCRIPTION                   = "This is a sample calibration file
for use with the PDS Rings Node Profile Library. It is based on file
CALIB/PS1C01.TAB from the Voyager PPS ring occultation data set,
volume VG_2801.

This is a table of calibration parameters associated with the Voyager
2 PPS egress occultation of delta Scorpii by Saturn's rings.
Parameters are given as a function of PPS record index, referring to
records in the file EDITDATA/PS1D01.DAT. Record 0 indicates the
beginning time of the first record, which falls at FDS 44001:06:601.

This particular file assumes that the number of stellar photons per
PPS sample is a constant, and uses an empirical model for the
background photons based on fits to various transparent and opaque
regions of the data. The model was derived originally by the PPS
team. See
    Esposito, L. W., et al. 1983. Voyager photopolarimeter stellar
    occultation of Saturn's rings. J. Geophys. Res. 88, 8643-8649.
It is assumed here that uncertainties in the background and stellar
signals are constant and uncorrelated. This file was generated by
running program DOCUMENT/CALIB/PS1C01.FOR."

  OBJECT                        = COLUMN
    NAME                        = RECORD_INDEX
    DATA_TYPE                   = ASCII_INTEGER
    START_BYTE                  = 1
    BYTES                       = 4
    UNIT                        = 'N/A'
    FORMAT                      = "I4"
    DESCRIPTION                 = "Record index value. Each PPS data
record consists of 600 samples, where the first record in the data
file has index 0."
  END_OBJECT                    = COLUMN

  OBJECT                        = COLUMN
    NAME                        = TOTAL_SIGNAL
    DATA_TYPE                   = ASCII_REAL
    START_BYTE                  = 6
    BYTES                       = 9
    UNIT                        = 'N/A'
    FORMAT                      = "F9.5"
    DESCRIPTION                 = "Total expected photons (background
plus stellar) per PPS sampling interval. This is the unocculted
signal level, i.e. that expected when no ring is present."
  END_OBJECT                    = COLUMN

  OBJECT                        = COLUMN
    NAME                        = STELLAR_SIGNAL
    DATA_TYPE                   = ASCII_REAL
    START_BYTE                  = 16
    BYTES                       = 9
    UNIT                        = 'N/A'
    FORMAT                      = "F9.5"
    DESCRIPTION                 = "Expected stellar photons
per PPS sampling interval."
  END_OBJECT                    = COLUMN

  OBJECT                        = COLUMN
    NAME                        = BACKGROUND_SIGNAL
    DATA_TYPE                   = ASCII_REAL
    START_BYTE                  = 26
    BYTES                       = 9
    UNIT                        = 'N/A'
    FORMAT                      = "F9.5"
    DESCRIPTION                 = "Expected background photons per PPS
sampling interval. This is the fully occulted signal level, i.e. that
expected when a ring is completely opaque."
  END_OBJECT                    = COLUMN

  OBJECT                        = COLUMN
    NAME                        = TOTAL_SIGNAL_UNCERTAINTY
    DATA_TYPE                   = ASCII_REAL
    START_BYTE                  = 36
    BYTES                       = 9
    UNIT                        = 'N/A'
    FORMAT                      = "F9.5"
    DESCRIPTION                 = "Approximate standard deviation in
the total expected photons."
  END_OBJECT                    = COLUMN

  OBJECT                        = COLUMN
    NAME                        = STELLAR_SIGNAL_UNCERTAINTY
    DATA_TYPE                   = ASCII_REAL
    START_BYTE                  = 46
    BYTES                       = 9
    UNIT                        = 'N/A'
    FORMAT                      = "F9.5"
    DESCRIPTION                 = "Approximate standard deviation in
the expected stellar photons."
  END_OBJECT                    = COLUMN

  OBJECT                        = COLUMN
    NAME                        = BACKGROUND_SIGNAL_UNCERTAINTY
    DATA_TYPE                   = ASCII_REAL
    START_BYTE                  = 56
    BYTES                       = 9
    UNIT                        = 'N/A'
    FORMAT                      = "F9.5"
    DESCRIPTION                 = "Approximate standard deviation in
the expected background photons."
  END_OBJECT                    = COLUMN

  OBJECT                        = COLUMN
    NAME                        = STELLAR_BACKGROUND_CORRELATION
    DATA_TYPE                   = ASCII_REAL
    START_BYTE                  = 66
    BYTES                       = 9
    UNIT                        = 'N/A'
    FORMAT                      = "F9.5"
    DESCRIPTION                 = "Approximate statistical correlation
between the stellar and background photon estimates. Note that this
value approaches -1 when the only strong constraint is on the the
total free-space signal, i.e., on the sum of stellar and background
signals."
  END_OBJECT                    = COLUMN

END_OBJECT                      = SERIES
END