NSSDCA ID: PSFP-00353
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
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 straightforward. 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.
These data are available on-line from the Planetary Data System (PDS) at:
https://pds-ppi.igpp.ucla.edu/data/CO-V_E_J_S_SS-RPWS-4-SUMM-KEY60S-V1.0/
Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II
Name | Role | Original Affiliation | |
---|---|---|---|
Prof. Donald A. Gurnett | Data Provider | University of Iowa | |
Dr. William S. Kurth | General Contact | University of Iowa | wsk@space.physics.uiowa.edu |