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STARDUST 9P/TEMPEL 1 CIDA 2/3 NEXT V1.0 (PDS)

NSSDCA ID: PSSB-00541

Availability: Archived at NSSDC, accessible from elsewhere

Time span: 2005-06-10 to 2011-02-15

Description

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

Data Set Overview

This description was written by J. Kissel, J. Silen, B. Semenov, C. Acton and J. Ryno.

This data set contains Level 2 and 3 time-of-flight spectrum data, and associated ancillary data, produced by the Stardust Cometary and Interstellar Dust Analyzer Instrument (CIDA), a time-of-flight mass spectrometer. The data were obtained during two episodes of the Stardust-NExT extended mission: flyby of comet Tempel 1; and cruise, which includes all other times except the flyby ([VEVERKAETAL2011], [KISSELETAL2003], [GREENETAL2004]). The spectra are called 'events.' Each package of 'event' and ancillary data was telemetered to the ground as an Experiment Data Frame (EDF). The term 'event' is used to refer to any type of non-ancillary data returned from the CIDA instrument. Some of these events are test frames, generated by telecommands to ensure continued correct operation of the instrument. Some events are the result of a CIDA re-boot, which may have been commanded or may have been a result of some other spacecraft condition. Some events are known to have been generated by noise within the CIDA electronics. All of these are considered non-scientific data and are distinguished from scientific data by TARGET_NAME set to 'NON SCIENCE' in the data labels and the data set index file. 588 of 705 (83%) EDFs in this data set contain non-scientific data. The remainder are events that may or may not contain spectra resulting from actual particle hits; it is only through detailed analysis that the user may make a determination of the cause of the event and the resulting spectra may be interpreted. These EDFs are distinguished by TARGET_NAME in the labels and index file set to either '9P/TEMPEL 1 (1867 G1)' (80 of 705 EDFs) or 'INTERSTELLAR PARTICLES' (37 of 705 EDFs). While included for completeness, the CIDA housekeeping and other ancillary data are NOT needed for generation or interpretation of CIDA spectra. The CIDA event files include selected observation geometry parameters, derived from the then-current SPICE kernels and allied SPICE Toolkit software. These SPICE kernels are available in a separate PDS Stardust data set, SDU-C-SPICE-6-V1.0. The CIDA event data are supplemented with a PDS index file providing a set of parameters computed for every CIDA event; this information may be easily loaded into a database or spreadsheet to facilitate searches for CIDA data meeting certain user-specified observing conditions. Data Collection Periods ======================= Cruise Collection Period -----------------------During the cruise from Wild 2 to Tempel 1 the CIDA instrument was operating (in CRUISE mode) during the following times: Start Stop ------------------- ------------------2005-06-10 2005-07-07 2005-09-01 2005-11-18 2007-01-25 2007-01-25 2007-11-20 2008-10-14 2009-03-30 2009-08-05 2009-08-14 2009-10-21 2009-11-02 2009-11-09 2009-12-07 2010-02-17 2010-02-18 2010-05-03 2010-05-11 2010-05-25 2010-06-29 2010-06-29 2011-02-02 2011-02-02 2011-02-14 2011-02-15 There were a number of OFF times during these periods as a result of the spacecraft going into safe-mode, spacecraft maneuvers, and other reasons. Between 2009-10 and 2010-02 CIDA sensitivity against spacecraft operations was tested by lowering the data acquisition trigger sensitivity. No correlation between spacecraft activity and CIDA events was found. Tempel 1 Encounter Collection Period -----------------------------------During the Tempel-1 encounter the CIDA instrument was operating (in ENCOUNTER mode) during the following time: Start Stop ------------------- ------------------2011-02-14T04:51:22 2011-02-15T05:49:01 Data Calibration ================ The 'calibration' of time-of-flight mass spectrometer data is in fact the essence of the data analysis process. 'Calibration' of the data numbers contained in each event, resulting in a determination of if a particulate impact actually occurred, and if so, of the composition of the particle, may be straightforward, but may instead be complex and subjective. This data set includes a document, CALEXAMPL.LBL, providing a complete description of the 'calibration' of a laboratory test event where the composition of the particle is well known. The document also includes a similar 'calibration' example for an in-flight event obtained during the Wild 2 flyby. Data Product Type and Format 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 EDR and RDR 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, the format and contents of which are defined in the CIDASIS.LBL/.ASC document included in the archive. 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. The label format and contents are described in detail in the ONLABELS.TXT file included in the archive. Parameters ========== Spectral and Other Non-Ancillary Data ------------------------------------All events are stored as spectral data in PDS TABLEs, regardless of TARGET_NAME. Each row of a spectrum TABLE represents one mass line of a time-of-flight spectrum. Each mass line (TABLE row) contains - five CIDA channel raw (EDR) counts, as data numbers (DN) - five CIDA channel calibrated (RDR) charges, in picocouloumbs As mentioned above, it is important to note that not all event data stored as spectra in PDS TABLEs are actually spectra, because some non-particle-impact phenomena triggered CIDA to take and store data as 'events.' Ancillary Data -------------Ancillary data are also stored in PDS TABLEs, with each row containing data for a sample time. The times are stored in the first column in the TABLEs. Ancillary data include a variety of parameters (temperatures, voltages, states such as ON and OFF, &c), too numerous to list here. Refer to the TABLE PDS labels for the meaning of each parameter. Sampling Intervals -----------------There are no set intervals for data sampling in CIDA. CIDA generated an event when an internal algorithm determined that a particle may have hit the target. The recovery time to prepare for the next event was about 80ms. Other events and housekeeping data could be initiated by commands from the ground, automatic processes on the spacecraft, or anomalous spacecraft events (e.g. reboot, safing). For more details of the CIDA sampling algorithm, and its dependence on operating mode (CRUISE or ENCOUNTER), see [KISSELETAL2003] and [GREENETAL2004]. Data Processing =============== The Stardust CIDA instrument output consisted of a variety of binary data blocks called binary Experiment Data Files (EDFs), each of which contained a set of spectrum or housekeeping data. On board the spacecraft, EDFs were packetized by the spacecraft's flight software and downlinked within packets in the spacecraft telemetry stream. For small housekeeping EDFs, multiple EDFs were contained in one spacecraft telemetry packet, while for large spectrum EDFs, the EDF was split between a few spacecraft packets. A suite of software -- developed and run by the Stardust Data Management and Archive Team (DMA) and collectively referred to as CIDA Telemetry Processing Software (CTPS) -- retrieved packets with CIDA data from the Telemetry Data Server(s)(TDS) used by the Stardust Project, stripped off ground system and spacecraft packet headers, and placed the EDF data in a binary EDF collection file for delivery to the CIDA science team. That binary file essentially contained a 'chunk' of a single stream of concatenated EDFs. The binary EDF collection files were then delivered to the CIDA science Team, which used a set of software -- developed and run by the Finnish Meteorological Institute (FMI) and called EDFPARSER/EDF2ASCII -- to combine 'chunks' into a single telemetry stream, extract individual binary EDFs from it, convert binary data from individual EDFs into ASCII and save the ASCII Spectrum EDF and ASCII HK EDF files in the format in which the data are provided in this data set. For Spectrum EDF data the conversion constituted simply printing byte values as ASCII integers and did not involve any scaling and/or calibration of the values. For the generic EDF header data and HK EDFs it in some cases involved de-multiplexing fields and converting ancillary fields containing count values into physical units -temperatures, voltages, etc. Ancillary Data ============== Each Spectrum EDF file includes a table containing a number of derived geometry parameters. These parameters were computed using the following SPICE kernels archived in the Stardust SPICE data set, SDU-C-SPICE-6-V1.0: Kernel Type File Name ------------ -----------------------LSK naif0009.tls PCK pck00009.tpc SCLK sdu_sclkscet_00186.tsc FK sdu_v20.tf SPKs sdu_tempel1_ssd_s154.bsp' sdu_isp000.bsp' sdu_l_1999.bsp' sdu_l_2000.bsp' sdu_l_2001.bsp' sdu_l_2002.bsp' sdu_l_2003_w2.bsp' sdu_l_2004.bsp' sdu_l_2005_return.bsp' sdu_l_2006.bsp' sdu_l_2007.bsp' sdu_l_2008.bsp' sdu_l_2009.bsp' sdu_l_2010.bsp' sdu_l_2011_t1.bsp' CKs sdu_sc_rec_1999_v2.bc sdu_sc_rec_2000_v2.bc sdu_sc_rec_2001_v2.bc sdu_sc_rec_2002_v2.bc sdu_sc_rec_2003_w2_v2.bc sdu_sc_rec_w2_opnav.bc sdu_sc_rec_2004_v2.bc' sdu_sc_rec_2005_v2.bc' sdu_sc_rec_next.bc' ------------ -----------------------Coordinate System ================= The geometry items provided in the geometry table of the Spectrum EDF files are relative to either the ecliptic reference frame of J2000 or the Stardust spacecraft reference frame. Refer to the specification of the geometry table columns to see which parameters are defined in which frame. The ecliptic reference frame of J2000 is defined as follows: - +Z axis is along Ecliptic North at J2000 epoch (2000 JAN 01 12:00 ET); - +X axis is along vernal Equinox at J2000 epoch; - +Y completes the right hand frame; The Stardust reference frame is defined as follows: - +X axis is along the longer side of the spacecraft bus and points from the aerogel capsule side towards the dust shield side; - +Z is perpendicular to the deployed solar arrays surface and points along the HGA pointing direction; - +Y completes the right hand frame; - the origin of this frame is at the center of the launch vehicle interface ring attached to the shield side of the spacecraft bus. This diagram illustrates the spacecraft reference frame and CIDA mounting with respect to it: || Dust Collector || Array Solar Array Main || Shield +Z .-. Shield || .-. ^| | o | |==========|====o===============o=============== `-' || |-------------------. . Solar || | |/| Array || | .-----. CIDA | | <-------o| | | ' | | Return +X +Y . __/ | | Capsule | | `. `. || | |--- `. `.---- -----' o--------| | `. `. _______/ `-' `.'`. Target ------> ------> ------> .' -------Nominal . ' Incoming Particle `. ' 40 deg direction during `. Encounter `. Normal to CIDA Target Plane As seen on the diagram CIDA is mounted on the +Y side of the spacecraft bus. The CIDA target plane is parallel to the spacecraft Y axis. The normal to the target plane is in the XZ plane and 40 degrees from +X towards +Z. The back of the opening between the target and the entrance to the drift tube is shielded, not permitting particles coming from the back (-X side) or top (+Z side) to hit the target. The un-shielded part of the opening and non-planar geometry of the target surface allow impacts by the particles coming from within the angular range of a few degrees towards +Z and about 30 degrees toward -Z, measured from the +X axis. Software ======== The data in this data set are in standard PDS format -- ASCII text files with comma-delimited, fixed-width columns -- and, therefore, can be viewed by PDS-provided programs or loaded into commercial programs that support comma-delimited formats. For this reason no special processing software is included in this data set. Contact Information =================== For any questions regarding the data in this archive, contact: Dr. Jochen Kissel, Stardust CIDA Science Lead Dr. Johan Silen, Stardust CIDA Science Team Member Jouni Ryno, Stardust CIDA S/W Technical Lead

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

http://pdssbn.astro.umd.edu/holdings/sdu-c_d-cida-2_3-next-tempel1-v1.0/

Alternate Names

  • SDU-C/D-CIDA-2/3-NEXT-TEMPEL1-V1.0

Discipline

  • Planetary Science: Small Bodies

Additional Information

Spacecraft

Experiments

Questions and comments about this data collection can be directed to: Dr. David R. Williams

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. Jochen KisselData ProviderMax-Planck-Institut fur Kernphysik
Mr. Jouni A. RynoGeneral ContactFinnish Meteorological Institutejouni.ryno@fmi.fi
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