Cometary and Interstellar Dust Analyzer Data Format Specification prepared by Jouni Ryno Johan Silen Finnish Meteorological Institute and Charles Acton Boris Semenov Jet Propulsion Laboratory Revision History ====================================================================== Version Date Changes ------- ----------- ------------------------------------------ 1.0 19 DEC 2001 Original version 2.0 04 MAY 2003 Complete rewrite. Acronyms ====================================================================== CIDA Cometary and Interstellar Dust Analyzer instrument EDF Experiment Data Frame PDS Planetary Data System SDU Stardust mission Purpose and Scope of Document ====================================================================== The purpose of this document is to provide a detailed description of the format, naming convention, and location within the archive of the science and housekeeping data files produced from telemetry of the Cometary and Interstellar Dust Analyzer (CIDA) instrument flying on the NASA Stardust (SDU) Spacecraft. These data will be archived within NASA's Planetary Data System (PDS). Overview ====================================================================== CIDA data files provided in this archive are divided into two main categories: -- Spectrum Experiment Data Files (Spectrum EDFs), and -- Housekeeping Experiment Data files (HK EDFs). Spectrum EDFs contain the raw CIDA time-of-flight spectrum data. Each Spectrum EDF file is sufficient for analysis in itself. HK EDFs contain temperature, voltage and other engineering data that might prove useful in reviewing the operating characteristics of the instrument, but are NOT needed to interpret the spectrum data. There is only one type of Spectrum EDF, but there are five different types of HK EDFs: -- housekeeping parameters -- configuration parameters -- calibration parameters -- global variable values -- interrupt variable values All CIDA data files are plain ASCII text files containing an attached PDS label. The data are in the form of one (for HK EDFs) or a few (for Spectrum EDFs) PDS-style, fixed-width-column, comma-delimited tables. Each table contained in the file is identified in the attached label by a separate TABLE object pointing to an external table format file specifying individual table columns. File Naming Scheme and Location on the Archive Volume ====================================================================== This section provides the file name specification and location within the archive volume directory structure for CIDA products. Spectrum EDF File Name and Location ----------------------------------- CIDA Spectrum EDF files are named as follows: TYYYYMMDDHRMNSCx.TAB where T -- is a leading character identifying that the number following it is time; YYYYMMDDHRMNSC -- is the approximate time (UTC) when the spectrum was collected; x -- is a character indicating the collection order of the measurement within the seconds portion of the time field, starting from "A". .TAB -- is standard PDS extension for ASCII table files; These files are located under the DATA/EDFASCII directory of the archive under which they are further binned by collection period -- ISP1, ENCOUNTER, etc. -- and under collection period by instrument operation mode -- POSITIVE or NEGATIVE. The following table format definition files are present in each sub-directory containing Spectrum EDF files: CIDA_HEADER.FMT CIDA_GEOMETRY.FMT CIDA_EVENT.FMT (More details about the format files are provided later in this document.) HK EDF File Name and Location ----------------------------- CIDA HK EDF files are named as follows: TYPE_TYYYYYMMDD_TYYYYMMDD.TAB where TYPE -- is HK data type identifier, one of: HK for housekeeping parameters KEEP for configuration parameters CALIB for calibration parameters GLOBALS for global variable values INFO for interrupt variable values T -- is a leading character identifying that the number following it is time; YYYYMMDD -- are the file coverage start and stop times; .TAB -- standard PDS extension for ASCII table files; These files are located under the DATA/HKVALUES directory of the archive under which they are further binned by collection period -- ISP1, ENCOUNTER, etc. The following table format definition files are present in each sub-directory containing HK EDF files: CIDA_HEADER.FMT CIDA_HK.FMT CIDA_KEEPALIVE.FMT CIDA_CALIB.FMT CIDA_GLOBALS.FMT CIDA_INFO.FMT (More details about the format files are provided later in this document.) Data Format ====================================================================== This section provides the file contents and format specification for CIDA products. Spectrum EDF Format ------------------- Each individual CIDA Spectrum EDF is a plain ASCII text file containing (in the order they appear in the file): -- multi-line attached PDS label -- one-line CIDA packet header information table -- one-line CIDA geometry information table -- multi-line CIDA spectrum data ("event" table) Each line in the file is terminated with a CR-LF pair. The tables are PDS-style tables -- fixed record length, fixed width columns, comma-delimited. The attached PDS label located at the beginning of the file consists of a few sections containing the product identification keywords and of a section containing PDS TABLE object specifications, -- one for each of the three data tables. The keywords included in the identification section of the label are defined in the ONLABELS.TXT document provided in the archive's DOCUMENT directory. The CIDA packet data header information table contains a set of housekeeping values that were included in the header of each telemetry data packet generated by the instrument. All of these values were generated by the instrument, not added by the spacecraft telemetry or ground data system. The content of the header table is sufficient to define the state of the instrument. This table includes the time when the spectrum was measured, mode id(s), particle hit rates, etc. The complete set of definitions and descriptions for individual columns is provided in the CIDA_HEADER.FMT file. The CIDA geometry information table contains a set of geometry parameters computed for the time at which the spectrum was measured, using the latest SPICE data available at the time when the file was generated. This table includes spacecraft position and velocity relative to the Sun, spacecraft orientation parameters, etc. The complete set of definitions/descriptions for individual columns is provided in the CIDA_GEOMETRY.FMT file. The CIDA spectrum data table contains the CIDA spectrum data. This table is made up of ten columns, each containing five raw measurements (counts) and five equivalent calibrated measurements (picocoulombs) from high straight, high delayed, low straight, low delayed, and target data correspondingly. The formal individual column definitions/descriptions are provided in the CIDA_EVENT.FMT file; Further information is available in the DATA/DATAINFO.TXT file. HK EDF Format ------------- Each individual CIDA HK EDF is a plain ASCII text file containing (in the order they appear in the file): -- multi-line attached PDS label -- multi-line CIDA HK data table of a particular type Each line in the file is terminated with a CR-LF pair. The table is a PDS-style table -- fixed record length, fixed width columns, comma-delimited. The attached PDS label located at the beginning of the file consists of a few sections containing the product identification keywords and a section containing PDS TABLE object specifications. The keywords included in the identification section of the label are defined in the ONLABELS.TXT document provided in the DOCUMENT directory. Each line in the CIDA HK data table consists of two parts, identified by container sub-objects in the TABLE object: - CIDA header information, appearing at the beginning of the record, and -- CIDA HK data of a particular type -- housekeeping, configuration or calibration parameters, or global or interrupt variables -- appearing at the end of the record. CIDA packet data header container provides the same set of items and has the same format, specified in the CIDA_HEADER.FMT file, as the header table in Spectrum EDFs. The housekeeping parameters container provides instrument analog status, including several critical temperatures and low and high voltage subsystem voltages and currents. The complete set of definitions/descriptions for individual columns of this container is given in the CIDA_HK.FMT file. The configuration parameters container provides instrument software status, fast data acquisition (FDAQ) analog setup, encounter data collection strategy parameters and telemetry usage. The complete set of definitions/descriptions for individual columns of this container is given in the CIDA_KEEPALIVE.FMT file. The calibration parameters container provides the result of the FDAQ calibration. The four analog-to-digital channel baselines are calibrated, and event trigger digital-to-analog setup is calibrated so that it will not trigger to noise pulses. The complete set of definitions/descriptions for individual columns of this container is given in the CIDA_CALIB.FMT file. The global variable values container provides a snapshot of the global software variables, which are used to control the instrument but are not part of the instrument configuration nor are they derived from them. The complete set of definitions/descriptions for individual columns of this container is given in the CIDA_GLOBALS.FMT file. The interrupt variable values container provides a snapshot of the variables, which the software interrupt subsystem uses as status, counters or temporal placeholders for common registers. The complete set of definitions/descriptions for individual columns of this container is given in the CIDA_INFO.FMT file. Note that these data are not included in the Stardust-NExT mission, and neither is the file CIDA_INFO.FMT.