Data Set Overview
  =================
    The Cassini Radio and Plasma Wave Science (RPWS) calibrated summary
    key parameter data set includes reduced temporal and spectral
    resolution spectral information calibrated in units of spectral
    density for the entire Cassini mission.  This data set includes
    calibrated values binned and averaged within 1 minute by 0.1 decade
    spectral channels for all times during the mission including the two
    Venus flybys, the Earth flyby, the Jupiter flyby, interplanetary
    cruise, and the entire Saturn tour.  Data for this data set are
    acquired by the RPWS Low Frequency Receiver (LFR), Medium Frequency
    Receiver (MFR), and High Frequency Receiver (HFR).  Data are
    presented in a set of fixed-record-length tables.  This data set is
    intended to provide numerical summary data which can be used in
    conjunction with other Cassini fields and particles key parameter
    data sets to establish trends, select events, or simply as a browse
    data set for the Cassini RPWS archive.  This data set should be
    among the first used by a user of any of the RPWS archive as it will
    lead one to information required to search for more detailed or
    highly specialized products.


  Parameters
  ==========
    This data set comprises electric and magnetic field spectral
    densities for each sensor, binned and averaged (median) into moderate
    resolution frequency and time bins.  We use 10 spectral channels per
    decade logarithmically spaced in frequency, usually from 1 Hz to 16
    MHz, and a 1-minute time step.


  Processing
  ==========
    Data in this data set were processed by the use of a number of
    software programs which assemble segmented mini-packets in the raw
    telemetry packets into complete sets, de-compress the data that were
    compressed by one of a number of compression algorithms by the RPWS
    flight software onboard, apply conversion lookup tables or
    algorithms to convert telemetry data numbers into physical units,
    make any corrections required for antenna capacitive loading or
    other effects, bin the measurements into frequency and time bins,
    and then determine the median of all measurements within a bin.
    These data are calibrated using the best calibration tables and
    algorithms available at the time the data were archived.  See
    chapters 5 - 11 of the RPWSCAL document in the DOCUMENT directory
    for details on how the data included in this data set were
    calibrated.  Should a significant improvement in calibration become
    available, an erratum will be noted in the erratum section.  Later
    versions of data products may contain better calibrations.  It
    should be noted, however, that since measurements from different
    sensors are binned (via finding the median measurement in the bin)
    the resulting spectrum is an amalgamation of different sensors
    oriented in different directions.  Hence, the detailed
    interpretation of this data set is not necessarily straight-
    forward.  If the user is interested in the best calibrated value
    with a minimum of interpretational issues, the Low Rate Full
    resolution data product would be the best source of information.


  Data
  ====
    The RPWS key parameter data set includes tables of wave spectra as a
    function of time using measurements from each of the various
    receivers of the RPWS, including the LFR, MFR, and HFR.  Each table
    will contain fixed-length records including columns for time and
    spectral densities for each channel.


  Ancillary Data
  ==============
    Ancillary data included with this data set collection include a
    series of files that describe the modes of the RPWS as a function of
    time and provide a time-ordered listing of Instrument Expanded Block
    (IEB) trigger commands (the mode by which the RPWS is reconfigured).
    Also a detailed description of each of the modes (or IEBs) is
    provided.

    Other data which are ancillary to this data set but which are
    archived separately from this collection are the Navigation and
    Ancillary Information Facility's SPICE kernels describing the
    position and attitude of Cassini and various solar system bodies as
    a function of time.


  Coordinate System
  =================
    The data in this data set are measurements of wave electric and
    magnetic fields measured by the RPWS electric and magnetic sensors.
    These fields are presented as detected by the sensors and are not
    rotated into any other coordinate system.  If desired the SPICE
    kernels can be used with the SPICE toolkit to convert from the
    spacecraft frame to virtually any frame which may be of use in
    analyzing these data.  However, for many purposes, the wave
    amplitudes are extremely useful and may be entirely adequate with no
    coordinate transformations at all.


  Software
  ========
    Since the data are provided in text files as fully calibrated
    amplitudes, no example software is provided for reading these data.
    However, a platform-independent Java (TM) application is provided in
    EXTRAS/SOFTWARE/KEY_BROWSE.JAR which can read these data and produce
    spectrograms with user-selectable options.  See README.TXT in the
    same directory for further information.


  Media/Format
  ============
    These data are supplied to the Planetary Data System on DVD-R media
    using formats and standards of the PDS for such media.

Confidence Level Overview
  =========================
    This data set contains all low rate key parameter data for the
    Cassini RPWS instrument for the intervals described In the product
    label files.  Every effort has been made to ensure that all data
    returned to JPL from the spacecraft are included and that the
    calibration is accurate. A column in each record indicates whether
    the confidence in the data in that record is high (0) or not (9).
    The middle band of the MFR (Band 2, 180 - 1500 Hz) has shown a
    tendency to have an increased noise level by as much as 10 dB at
    times, although there is no current explanation for this or
    known factor which would enable this condition to be predicted.
    In some instrument modes data are collected in the high band of
    the WFR which can be used to replace the data in MFR Band 2,
    although this replacement has not been done for this data set.
    The replacement data are included in the low resolution, fully
    calibrated data set, however.


  Review
  ======
    The RPWS calibrated summary key parameter data will be reviewed
    internally by the Cassini RPWS team prior to release to the PDS.
    The data set will also be peer reviewed by the PDS.


  Data Coverage and Quality
  =========================
    All data in the intervals described in the product label files are
    included, to the best of our knowledge and attempts to determine
    completeness.  In general, the instrument was operated only briefly
    during early tour for the following intervals:

    1.  Antenna deployment   1997-10-25T00:00 - 1997-10-26T05:30
    2.  Venus 1 flyby        1998-04-26T12:54 - 1998-05-08T19:21*
    3.  Instrument Checkout  1998-12-30T09:10 - 1999-01-19T05:40
    4.  Venus 2 flyby        1999-06-24T09:08 - 1999-06-24T21:20
    5.  Earth flyby          1999-08-13T17:39 - 1999-09-14T22:20

    *Actual interval for science data is much shorter than this.

    Beginning in February of 2000 the instrument was operated
    more-or-less continuously; two gaps of the order of six weeks were
    incurred for the purposes of loading new attitude control and
    command and data system flight software, gaps of a few days each
    were incurred approximately twice per year because of Huygens Probe
    testing, and gaps of several days in duration occurred during solar
    conjunction periods prior to 2002. Remaining gaps are due to
    spacecraft anomaly resolution or simply to downlink gaps, some of
    which were imposed by limitations on DSN station availability.


  Limitations
  ===========
    One measurement quality issue is occasional elevated noise levels
    (by a few to 10 dB) in the second band of the MFR. During tour, it
    is anticipated that data from the Waveform Receiver (WFR) sometimes
    referred to as the medium frequency digital receiver (MFDR) can be
    substituted for these in the full resolution data product (RPWS LOW
    RATE FULL).

    Beginning approximately with Saturn orbit insertion in early July
    2005, the RPWS has shown increasing sensitivity in its electric
    field measurements below 2 kHz to interference from the spacecraft
    reaction wheels.  The wheels are a source of electromagnetic
    interference in the magnetic channels at frequencies directly
    related to the rotation rate of the wheels due to a residual
    magnetic moment in the wheels.  This level was predicted before
    launch and has been basically constant through flight.  However, at
    the earliest opportunity to observe the interference of the wheels
    on the electric field measurements, there was essentially no
    detectable level of interference.  However, after orbit insertion,
    it became clear with increasing time that the wheels were becoming
    an increasing source of interference in the electric field
    measurements at about 2 kHz and below.  As of late 2005, the
    amplitude of this interference is of the order of 30 or 40 dB above
    the instrument  noise level.  The relation of the frequency of the
    electric interference to the rotation rate of the wheels is less
    direct than for the magnetic interference.  There is a general
    correspondence, but not in detail.  It appears that there are some
    frequencies more susceptible to the interference than others and
    when the wheel speed approaches these 'resonances', the interference
    becomes more visible.  A working model for this interference
    proposes that radiation effects on some part(s) of the spacecraft,
    perhaps the thermal blankets, reduce the conductivity.  Small
    vibrations of this part(s), then, with some residual differential
    charging then result in the electric field interference.  This model
    is not confirmed and the true explanation of the interference is
    unknown, but the effects significantly complicate the interpretation
    of the electric field spectrum below 2 kHz.

  SCET Miscalculation
  ===================
    Version 1 of CORPWS data

       2008-12-28 through 2011-06-30

    were processed using invalid SPICE spacecraft clock kernels.
    Specifically the SCLKs which spice was asked to convert to SCETs
    were outside the valid correlation region.  The error was subtle at
    first but continued to grow as SCLKs further from the correlated
    region were converted to SCETs.  The net result was that incorrect
    SCET values were placed into the product files and product label
    files for these dates.  The issue has been corrected and no longer
    affects any CORPWS datasets available from the PDS.  The following
    table lists the maximum SCET errors by date.


Start Date    Stop Date      Version      Release Date     Max SCET error
-----------   ----------     --------     -------------    ---------------
2008-12-28    2009-01-12       1          2009-09-25       1.2 seconds
2009-01-13    2009-01-29       1          2009-12-17       1.3 seconds
2009-01-30    2009-02-12       1          2009-12-17       1.3 seconds
2009-02-13    2009-03-01       1          2009-12-17       1.4 seconds
2009-03-02    2009-03-29       1          2009-12-17       1.5 seconds
2009-03-30    2009-04-19       1          2009-12-17       1.5 seconds
2009-04-20    2009-05-16       1          2009-12-18       1.6 seconds
2009-05-17    2009-06-12       1          2009-12-18       1.7 seconds
2009-06-13    2009-06-26       1          2009-12-18       1.7 seconds
2009-06-27    2009-07-09       1          2009-12-18       1.7 seconds
2009-07-10    2009-07-25       1          2010-06-28       1.8 seconds
2009-07-26    2009-08-17       1          2010-06-28       1.9 seconds
2009-08-18    2009-09-09       1          2010-06-29       1.9 seconds
2009-09-10    2009-10-01       1          2010-06-30       1.9 seconds
2009-10-02    2009-10-21       1          2010-09-21       1.8 seconds
2009-10-22    2009-11-14       1          2010-09-21       1.9 seconds
2009-11-15    2009-12-10       1          2010-09-21       2.0 seconds
2009-12-11    2009-12-23       1          2010-09-21       2.0 seconds
2009-12-24    2010-01-13       1          2010-09-21       2.1 seconds
2010-01-14    2010-01-23       1          2010-09-21       2.2 seconds
2010-01-24    2010-02-02       1          2010-12-22       2.2 seconds
2010-02-03    2010-02-17       1          2010-12-22       2.2 seconds
2010-02-18    2010-02-27       1          2010-12-22       2.2 seconds
2010-02-28    2010-03-11       1          2010-12-22       2.3 seconds
2010-03-12    2010-03-22       1          2010-12-22       2.3 seconds
2010-03-23    2010-03-31       1          2010-12-22       2.4 seconds
2010-04-01    2010-04-16       1          2010-12-22       2.5 seconds
2010-04-17    2010-04-29       1          2010-12-22       2.6 seconds
2010-04-30    2010-05-10       1          2010-12-22       2.6 seconds
2010-05-11    2010-05-25       1          2010-12-22       2.7 seconds
2010-05-26    2010-06-08       1          2010-12-22       2.8 seconds
2010-06-09    2010-06-25       1          2010-12-23       2.9 seconds
2010-06-26    2010-08-07       1          2011-03-23       3.3 seconds
2010-08-08    2010-09-08       1          2011-03-23       3.6 seconds
2010-09-09    2010-10-15       1          2011-03-23       3.9 seconds
2010-10-16    2010-11-29       1          2011-09-29       4.1 seconds
2010-11-30    2011-01-03       1          2011-09-30       2.4 seconds
2011-01-04    2011-02-13       1          2011-12-21       2.7 seconds
2011-02-14    2011-03-24       1          2011-12-21       5.3 seconds
2011-03-25    2011-04-24       1          2011-12-21       7.3 seconds
2011-04-25    2011-05-09       1          2011-12-21       8.3 seconds
2011-05-10    2011-05-26       1          2011-12-22       9.4 seconds
2011-05-27    2011-06-12       1          2011-12-22      10.5 seconds
2011-06-13    2011-06-30       1          2011-12-22      11.7 seconds

    Only data from 2008-12-28 through 2011-06-30 with

        VERSION_VERSION_ID = 1

    are affected.  If VERSION_VERSION_ID is greater than 1, or the date
    is before 2008-12-28, or the the date is after 2011-06-30, then the
    data in question is unaffected by this issue.