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CASSINI E/J/S/SW MIMI INCA SENSOR UNCALIBRATED DATA V1.1 (PDS)

NSSDCA ID: PSFP-00811

Availability: Archived at NSSDC, accessible from elsewhere

Description

This description was generated automatically using input from the Planetary Data System.

Data Set Overview

The Cassini Magnetospheric Imaging Instrument(MIMI) Imaging Neutral Camera (INCA) uncalibrated data set includes all data collected from the MIMI Data Processing Unit during the entire Cassini mission [MANWEILERETAL2005]. The original data has been decommutated and decoded by software at the Applied Physics Laboratory (APL) and has been then further ordered and filtered by software at Fundamental Technologies, LLC. 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. This data set includes uncalibrated values of counts in the form of rates and of rate images for the INCA sensor for all times during the mission including the Earth flyby, the Jupiter flyby, interplanetary cruise, and the entire Saturn tour. Data are presented in a set of tables which are of variable length and use a comma to separate various fields. This data set is intended to be the most comprehensive and complete data set included in the Cassini MIMI INCA archive. 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 INCA archive as it will lead one to information required to search for more detailed or highly specialized features in the original data.

Parameters

This data set comprises counts per readout of charged and neutral particle imaging measurements for the single telescope of the INCA sensor accumulators and images. In addition this data set includes INCA PULSE HEIGHT ANALYSIS measurement data for a statistically select sample of the particle measurements. The standard product ID's are: INCA Accumulation Rate Data - individual microchannel plate detector count rate measurements INCA Image Data - count rates binned into a maximum of a 64x64 geometrical grid as an image, for various particle velocities. INCA Pulse Height Analysis Data - Statistically sampled set of discrete particle measurements. The data is organized in time by the spin of the spacecraft. When the spacecraft is in staring mode then the MIMI DPU automatically creates a virtual spin that divides the time collection periods into 16 sectors, 16 subsectors, and 16 microsectors and maintains a simple organizational structure for characterizing the collection of the time into time segments. When the spacecraft is spinning at a minimally defined spin rate (adopted by the MIMI DPU) then the MIMI data is automatically segregated into 16 sectors, 16 subsectors, and 16 microsectors. When the spacecraft is spinning and the LEMMS instrument is rotating the LEMMS rotation period is synchronized to the spacecraft spin period so that there are 16 sectors in a spin, 16 subsectors in a sector and 16 microsectors in a subsector. The CHEMS and INCA instrument collection times are then also keyed to these values.

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 MIMI flight software onboard and organize the channel data into appropriate time segments. Images are preprocessing into appropriate arrays on board the spacecraft. This preprocessing software also includes algorithms to handle the various spacecraft rotation modes.

Data

The MIMI INCA uncalibrated data set includes three ASCII CSV tables (each associated with a Standard Product ID) of INCA Rate data as a function of time collected from the MIMI INCA sensor and collated into data sets. Each table contains variable length records for which the fields are comma delimited. INCA Accumulation Rate Data --------------------------Fields include: a purpose identifier where science data records are identified with purpose = sci starting and ending ephemeris times Spin, sector, subsector (and for INCA Fine Rate (FRT) data microsector) SCLOCK and spin period that are used to derive the starting ephemeris time Notes regarding the SCLOCK value: 1. Only the SCLOCK major segment value is provided - MIMI currently does not have access to the fine SCLOCK value hence SCLOCK resolution is limited to +- 1/2 SCLOCK count 2. The SCLOCK is only available from telemetry at the beginning of each spin. All other published SCLOCKS are derived from the spin starting SCLOCK, the spin numbers (for the current and next available spins), and the spin period. 3. SCLOCK values are assumed to drive the value of the ephemeris times and not vice-versa. All effort is made to validate the published ephemeris times but since updates to the Cassini SCLOCK kernel in SPICE can occur the values of ephemeris time are only as accurate as the currently published Cassini SCLOCK SPICE kernel. Spacecraft staring mode where staring = 0 when spinning and 1 otherwise INCA Accumulation rate data organized as: Start fast, pulse, and Start-coincidence counts Stop fast, pulse, and Stop-coincidence counts Full, Coincidence, and time counts Events received and processed counts (MIMI INCA has 3 microchannel plates, the Start, the Stop, and the Coincidence plates. Start fast is the Start timing signal count; Start pulse is the Start pulse-height count; Start-coincidence is the count of the coincidences within the alotted time window of signals from the Start fast and the Coincidence microchannel plates; Full is the count of events with a Start fast, Stop fast, and Coincidence signal; time is the count of events with both a Start fast and a Stop fast; Events received is the number of valid events sent to the DPU, and processed counts are the number the DPU sends inot image bins. These latter two may be different because of additional valid event criteria imposed by the DPU, and/or inability of the DPU to process all of the events it receives.) INCA Images ----------Fields include: a purpose identifier where science data records are identified with purpose = sci starting and ending ephemeris times Spin, sector, subsector SCLOCK and spin period that are used to derive the starting ephemeris time Notes regarding the SCLOCK value: 1. Only the SCLOCK major segment value is provided - MIMI currently does not have access to the fine SCLOCK value hence SCLOCK resolution is limited to +- 1/2 SCLOCK count 2. The SCLOCK is only available from telemetry at the beginning of each spin. All other published SCLOCKS are derived from the spin starting SCLOCK, the spin numbers (for the current and next available spins), and the spin period. 3. SCLOCK values are assumed to drive the value of the ephemeris times and not vice-versa. All effort is made to validate the published ephemeris times but since updates to the Cassini SCLOCK kernel in SPICE can occur the values of ephemeris time are only as accurate as the currently published Cassini SCLOCK SPICE kernel. Spacecraft staring mode where staring = 0 when spinning and 1 otherwise INCA Images are organized as: Type ID: a 4 byte word characterized as: Byte 0 - Type: 0 = High Spatial, 1 = High Time, 2 = High m-TOF Byte 1 - Charge: 0 = Neutral, 1 = Ion Byte 2 - Species: 0 = H, 1 = He, 2 = CNO, 3 = Heavy, 4 = Other, 5 = All Byte 3 - TOF: 0 = Low, 1-6 = Medium, 7 = High Row ID: the row of the image which can vary from 8 to 64 based upon the image type Num Rows: the number of rows for this image Num Cols: the number of columns for this image which can vary from 8 to 64 based upon the image type Compression bits, Compression method, log compressed identifier Theta and Phi offsets from spacecraft coordinates Breakout of the type id into Type, Charge, Species, and TOF Column (0-63) counts representing the number of counts each pixel of this row x column received INCA Pulse Height Analysis Data ------------------------------Fields include: a purpose identifier where science data records are identified with purpose = sci starting and ending ephemeris times Spin, sector, subsector SCLOCK and spin period that are used to derive the starting ephemeris time Notes regarding the SCLOCK value: 1. Only the SCLOCK major segment value is provided - MIMI currently does not have access to the fine SCLOCK value hence SCLOCK resolution is limited to +- 1/2 SCLOCK count 2. The SCLOCK is only available from telemetry at the beginning of each spin. All other published SCLOCKS are derived from the spin starting SCLOCK, the spin numbers (for the current and next available spins), and the spin period. 3. SCLOCK values are assumed to drive the value of the ephemeris times and not vice-versa. All effort is made to validate the published ephemeris times but since updates to the Cassini SCLOCK kernel in SPICE can occur the values of ephemeris time are only as accurate as the currently published Cassini SCLOCK SPICE kernel. Spacecraft staring mode where staring = 0 when spinning and 1 otherwise Index in sector number - auto generated number to guarantee uniqueness within a sector INCA Pulse Height Analysis data organized as: Coincidence indicator, start and stop indicator Pulse height data from the front and rear plates Time of flight of this particle and the azimuth and elevation for this event mass range of this particle.

Ancillary Data

Included with the INCA data set volumes are ancillary data files representing the MIMI Key Parameter (KP) data. The MIMI KP data is a calibrated subset of the important channels for each of the MIMI detectors. The subset of channels have been identified to most reasonably show characteristic energetic particle events during the mission. The KP data is calculated at an arbitrarily defined 60 second cadence which is different than the approximate collection times for the instruments as identified below for standard operations: (It must be realized that the collection times vary based upon the telemetry rate but nothing more than a factor of 2, 4, or 8.) Instrument Product Type Approx Collection Time (s) -----------------------------------------------------------INCA Accumulation 7.5 INCA IMAGES 180 (2 sectors) INCA PHA 22 CHEMS Accumulation 4 CHEMS Science 5 (each subsector) CHEMS PHA 80 (each sector) LEMMS Accumulation 5 (each subsector) LEMMS Fine Rate 0.6 (each microsector) LEMMS PHA 5 (each subsector) Data points for each record of the KP data are first Quartile Filtered then averaged (except in the case where the median is zero) for each sector. The sectored data is then interpolated into the 60 second data cadence of the KP data file. The KP data is then converted into a flux in units of 1/(cm^2*sr*sec*keV) or for the case of CHEMS 1/(cm^2*sr*sec*keV/e) Browse plots for each of the KP data files are produced. There are 7 different browse plots available. Inst Wild Card File Name Plotted KP data -------------------------------------------------------------------LEMMS LEMMS_KP_ELEC_(yyyydoy)_(ver#).JPG KP LEMMS Electron flux LEMMS LEMMS_KP_ION_(yyyydoy)_(ver#).JPG KP LEMMS Ion flux CHEMS CHEMS_KP_HEP_(yyyydoy)_(ver#).JPG KP CHEMS Helium Plus flux per charge CHEMS CHEMS_KP_HEPP_(yyyydoy)_(ver#).JPG KP CHEMS Helium Plus Plus flux per charge CHEMS CHEMS_KP_HP_(yyyydoy)_(ver#).JPG KP CHEMS Hydrogen Plus flux per charge CHEMS CHEMS_KP_OP_(yyyydoy)_(ver#).JPG KP CHEMS Oxygen Plus per charge INCA INCA_KP_(yyyydoy)_(ver#).JPG Hydrogen TOF flux Usage Note ---------The KP browse data and associated browse plots are to be used as an initial characterization of the particle environment and are NOT to be used for publications. The data is not at publication quality and is provided as is.

Coordinate System

The data in this data set are measurements of count rates based upon the orientation of the INCA instrument (INCA Center look direction). Particle flux effects are then determined by transforming from a spacecraft centered coordinate system, properly rotated to account for the appropriate INCA telescope direction, into whatever external coordinate (reference system) is most appropriate.

Software

There is no sample software provided as of the writing of this catalog file although the calibration volume does provide algorithms for conversion of count rates into flux. In general the INCA Images are the main product and can be converted into a measurement of flux per species with these algorithms and the INCA PHA and Accumulation Rates data are used for determining the health and wellness of the INCA detectors.

Media/Format

These data are supplied to the Planetary Data System via electronic means and are then broken into segments based upon the media currently prescribed by PDS.

These data are available on-line from the Planetary Data System (PDS) at:

https://pds-ppi.igpp.ucla.edu/data/CO-E_J_S_SW-MIMI-2-INCA-UNCALIB-V1.1/

Alternate Names

  • CO-E/J/S/SW-MIMI-2-INCA-UNCALIB-V1.1

Discipline

  • Planetary Science: Fields and Particles

Additional Information

Spacecraft

Experiments

Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. Stamatios M. KrimigisData ProviderApplied Physics Laboratorytom.krimigis@jhuapl.edu
Dr. Jerry W. ManweilerGeneral ContactFundamental Technologies, LLCmanweiler@ftecs.com
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