The Cassini Magnetospheric Imaging Instrument (MIMI) Charge Energy Mass Spectrometer (CHEMS) uncalibrated data set includes all data collected from the MIMI Data Processing Unit during the entire Cassini mission. The data is provided in an uncalibrated form in conjunction with a PDS MIMI calibration volume COMIMI_0000 which provides specific algorithms for the derivation of calibrated data. Data are presented in a set of tables which are of variable length and use a comma to separate various fields.
A browse data set is included with Key Parameter data that is calibrated using the algorithms provided in the Calibration volume. In addition, a series of images are provided with the KP browse data that displays the KP data which can lead the user to the particular times of interest. This data set should be among the first used by a user of any of the MIMI CHEMS archive as it will lead one to information required to search for more detailed or highly specialized features in the original data. The Key Parameters data set is not intented for direct use, only as a guide to finding points of interest.
This data set comprises count rates associated with mass and energy spectrometer measurements for each telescope of the CHEMS detector in accumulation and science modes. In addition this data set includes CHEMS PULSE HEIGHT ANALYSIS measurement data for a statistically select sample of the particle measurements. The standard product ID's are:
CHEMS Science Rate Data (CSCI0) - mass per charge, mass and charge count rate measurements.
CHEMS Pulse Height Analysis Data (CPHA0) - Statistically sampled set of discrete particle measurements.
CHEMS Accumulation Rate Data (CACC0) - telescope count rate measurements
CHEMS data set description
MIMI instrument description
Cassini mission description
Cassini spacecraft description
Data products have names of the following form:
CTTTF_YYYYDDD_VVVV.CSV
where
F is an index, starting with 0-9 and continuing to A-Z, that represents the format version of the file.
CTTTF follows the same convention described for directory names above
YYYYDDDHH is the start year and day of year of the data product,
VVVV is a numerical index, starting with 0000, that represents the data version of the file. Data used for testing purposes will set VVVV = 'TEST'