Data Set Overview : This data set contains magnetic-field data acquired during the cruise and tour phases of the Cassini mission to Saturn. On 16 August, 1999 two days before the spacecraft commenced Earth swingby, the magnetometer boom was unfurled into its extended position; a configuration it maintained for the remainder of the mission. Magnetic-field data acquired prior to boom deployment are limited and are significantly affected by spacecraft noise. These data are of no scientific value and, consequently, do not form part of this data set. Cassini carried two magnetometers: a fluxgate magnetometer (FGM) and a vector-helium magnetometer capable of operating in both vector and scalar mode (V/SHM). This data set contains calibrated, and averaged magnetic-field data recorded by the FGM instrument. The data are provided in both 1 second. The 1 second averaged data files span 1 quarter of year prior to arrival at Saturn, and 1 Saturn orbit following arrival at Saturn. The data are provided in RTN coordinates throughout the mission. After arrival at Saturn, the Saturn-centered KRTP, KSO, and KSM coordinates are also provided. Earth-centered, and Jupiter-centered coordinates are provided for the flybys of those two planets. All data files are ASCII. These data were calibrated, and rotated into geophysical coordinates by the Cassini MAG team at Imperial College (IC), and provided to the PDS/PPI node via the Cassini MAG team Co-I at UCLA. In other words these data use the same calibration as the data routinely delivered to the Cassini MAG team. Averaging for the 1 second data was performed at the PDS-PPI Node. Processing : Coordinate Systems : The coordinate systems in which the data are provided in vary by mission phase, and are designed to support both solar wind and planetary magnetospheric studies. Solar Wind Coordinates ---------------------- Radial-Tangential-Normal Coordinates (RTN) ------------------------------------------ RTN coordinates consist of R (radial component, Sun to the spacecraft), T (tangential component, parallel to the Solar Equatorial plane and perpendicular to R), and N (normal component, completes right handed set). Saturn-Centered Coordinates --------------------------- Kronocentric body-fixed, J2000 spherical Coordinates (KRTP) ----------------------------------------------------------- KRTP magnetic field vector components form the standard right-handed spherical triad (R, Theta, Phi) for a planet-centered system. Namely, R is radial (along the line from the center of Saturn to the center of the spacecraft), and positive away from Saturn. Phi, the azimuthal component, is parallel to the Kronographic equator (Omega x R) and positive in the direction of corotation. Theta, the 'southward' component, completes the right-handed set. Kronocentric Solar Magnetospheric Coordinates (KSM) --------------------------------------------------- KSM is a cartesian Saturn-center coordinate system where X points from Saturn to the Sun, the X-Z plane contains Saturn's centered magnetic dipole axis, M, and Y completes right handed set. Kronocentric Solar Orbital Coordinates (KSO) -------------------------------------------- KSO is a cartesian Saturn-centered coordinate system where X points from Saturn to the Sun, Z is parallel to Saturn's orbital plane upward normal, and Y completes the right handed set. Earth-Centered Coordinates -------------------------- Jupiter-Centered Coordinates ---------------------------- Jovicentric Body-Fixed (IAU_JUPITER) Coordinates (J3) ----------------------------------------------------- J3 is a body-fixed Jovicentric cartesian coordinate system consistent with the IAU 1997 definition of the System 3 prime meridian where X is in the Jovian equatorial plane, along S3 1997 Prime Meridian, Z is parallel to the Jovian spin axis, and Y completes right-handed set. Jovicentric Body-Fixed Magnetospheric Coordinates (JMXYZ) --------------------------------------------------------- JMAG XYZ is a body-fixed Jovicentric cartesian coordinate system where X is in the plane containing Z and the S3 1997 Prime Meridian, Z is the Jupiter magnetic dipole, and Y completes right handed set. SPICE : The data product labels associated with the data set include a list of the SPICE kernels that were used in calibrating the associated data, and coverting them to physical coordinates. While the SPICE kernels used are not part of this data set, these kernels are archived at the PDS-NAIF node on the volume cosp_1000. Note that the SPICE kernels listed in each of the product labels may be uniquely identified by their file name.

Product Versions : PRODUCT_VERSION_ID 1 data were calibrated at the PDS/PPI node at UCLA using software (CAL02), and calibration data provided by the Cassini MAG team. The process used the same calibration data that was provided with the Raw Magnetometer data archive (Data Set ID: CO-E/SW/J/S-MAG-2-REDR-RAW-DATA-V1.0). The data were then rotated into geophysical coordinates using MAG team additonal MAG team provided code (TRANSCAL) and spice kernels obtained from NAIF. The data were then averaged, and reformatted to ASCII using code developed at PDS/PPI. PRODUCT_VERSION_ID 2 data were calibrated, and rotated into geophysical coordinates by the Cassini MAG team at Imperial College, and provided to the PDS/PPI node via the MAG team Co-I at UCLA. Averaging to 1 second was performed at PDS/PPI (UCLA). The data were then reformatted at PDS/PPI to match the format used for the version 1 data. PRODUCT_VERSION_ID 3 have followed the same path as the version 2 data, however, the data have been recalibrated. PRODUCT_VERSION_ID 4 data were processed following the same procedure that was followed for the version 2 data. However, previously undetected mis-time tagged data which were present in the full-resolution data were removed prior to averaging the data to 1 second. More details on the timing errors are provided in the confidence level note (below). PRODUCT_VERSION_ID 5 data were processed following the same procedure that was followed for the version 4 data, including the removal of mis-timed data before averaging. In addition, version 5 products have been modified to satisfy liens set in the PDS peer review. Including a change in record formatting, and changes to the PDS labels.