PDS_VERSION_ID = PDS3
LABEL_REVISION_NOTE = "
2003-01-12, William Kurth (U. IOWA), initial;
2003-06-26, William Kurth (U. IOWA), general revision;
2004-02-10, William Kurth (U. IOWA), fixed liens;
2005-06-25, Larry Granroth (U. IOWA), minor tweaks;
2006-03-05, Larry Granroth (U. IOWA), added to limitations section;
2009-06-17, Chris Piker (U. IOWA), removed illegal keyword;
2012-06-20, Chris Piker (U. IOWA), add SCET miscalculation section;
2018-06-19, D. Kazden (PPI), Updated STOP_TIME and DATA_SET_RELEASE_DATE;
2018-07-30, D. Kazden (PPI), Removed ARCHIVE_STATUS keyword;
2020-02-04, D. Kazden (PPI), Updated CITATION_DESC;"
RECORD_TYPE = STREAM
OBJECT = DATA_SET
DATA_SET_ID = "CO-V/E/J/S/SS-RPWS-4-SUMM-KEY60S-V1.0"
OBJECT = DATA_SET_INFORMATION
DATA_SET_NAME = "
CASSINI V/E/J/S/SS RPWS SUMMARY KEY PARAMETER 60S V1.0"
DATA_SET_COLLECTION_MEMBER_FLG = "N"
DATA_OBJECT_TYPE = TABLE
START_TIME = 1997-10-25T00:00:00.000
STOP_TIME = 2017-09-15T00:00:00.000
DATA_SET_RELEASE_DATE = 2018-07-01
PRODUCER_FULL_NAME = "DR. WILLIAM S. KURTH"
DETAILED_CATALOG_FLAG = "N"
DATA_SET_TERSE_DESC = "
The Cassini Radio and Plasma Wave Science (RPWS) resampled
summary key parameter data set includes summary spectral
information calibrated in units of spectral density for the
entire Cassini mission."
ABSTRACT_DESC = "
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."
CITATION_DESC = "Kurth, W.S., T.F. Averkamp, and
L.J. Granroth, CASSINI V/E/J/S/SS RPWS SUMMARY KEY PARAMETER
60S V1.0, CO-V/E/J/S/SS-RPWS-4-SUMM-KEY60S-V1.0, NASA
Planetary Data System, 2018."
DATA_SET_DESC = "
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_NOTE = "
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.
"
END_OBJECT = DATA_SET_INFORMATION
OBJECT = DATA_SET_TARGET
TARGET_NAME = VENUS
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = EARTH
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = JUPITER
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = SATURN
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = SOLAR_SYSTEM
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = TITAN
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = ENCELADUS
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = MIMAS
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = DIONE
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = TETHYS
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = PHOEBE
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = IAPETUS
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = HYPERION
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = RHEA
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_HOST
INSTRUMENT_HOST_ID = CO
INSTRUMENT_ID = RPWS
END_OBJECT = DATA_SET_HOST
OBJECT = DATA_SET_MISSION
MISSION_NAME = "CASSINI-HUYGENS"
END_OBJECT = DATA_SET_MISSION
OBJECT = DATA_SET_REFERENCE_INFORMATION
REFERENCE_KEY_ID = "GURNETTETAL2004"
END_OBJECT = DATA_SET_REFERENCE_INFORMATION
END_OBJECT = DATA_SET
END
|