 
 
Stardust Spacecraft Orientation CK File, year 2005 + January 2006
===========================================================================
 
     Created on February 2, 2006 by Boris Semenov, NAIF/JPL.
 
 
Orientation Data in the File
--------------------------------------------------------
 
     This file contains orientation and angular velocity data for the
     Stardust (SDU) spacecraft frame, 'SDU_SPACECRAFT', relative to the
     'J2000' inertial frame. The NAIF ID code for the 'SDU_SPACECRAFT'
     frame is -29000.
 
 
Status
--------------------------------------------------------
 
     This file has been prepared for archiving with the Planetary Data
     System.
 
 
Pedigree
--------------------------------------------------------
 
     This file contains actual spacecraft orientation data that came
     from three different sources:
 
          -- regular operational spacecraft orientation C-Kernel
             file(s),
 
          -- special NAVCAM spacecraft orientation CK file, and
 
          -- Small Forces File (SFF).
 
     During mission operation all three types of files were produced by
     NAIF/JPL. All three inputs contained spacecraft orientation
     quaternions and angular rates computed by the AACS flight s/w
     on-board the spacecraft.
 
     The regular operational CK file(s) were generated by an automated
     process that extracted spacecraft orientation quaternions and
     angular rates from the channelized telemetry stream.
 
     The special NAVCAM spacecraft orientation CK file was generated by
     an automated process that extracted spacecraft orientation
     quaternions from the NAVCAM cruise image headers.
 
     The SFF file(s), containing spacecraft thruster activity
     information, were generated by an automated process that
     decomutated the small forces packets. Each of these packets
     included spacecraft orientation quaternion.
 
     At the time of the archiving data from regular and special CKs
     have been "dumped" into a text file using CK3DUMP program and the
     orientation data from the SFF have been extracted into another
     text file using a simple Perl script. After that the two data
     streams have been merged together, sorted, cleaned to remove
     duplicate records, and written to this CK file using MSOPCK
     program (see MSOPCK setup at the end of these comments.)
 
     Only "on-change" records from SFF were used because the
     orientation for the "other mode" SFF records was not
     representative of the instantaneous spacecraft orientation neither at
     the record start not at the record stop time. While the total
     quantity of SFF data was small compared the quantity of data from
     the ops CKs -- from 5% for the high downlink rate periods (when the
     spacecraft was close to Earth) to about 30% for the low rate downlink
     periods (when the spacecraft was far away), -- the SFF data were
     usually more dense for the periods when the spacecraft was not
     communicating with Earth. This and the fact that SFF data points
     were usually at the "edges" of AACS deadband made them very
     valuable for providing a better estimate of orientation for such
     periods.
 
     While all three sources contained the actual telemetered
     orientation data (quaternions), the actual angular rates were
     available only in the CK files. The angular rates for the SFF
     attitude stream have been "manufactured" using MSOPCK program
     assuming uniform constant rotation between the adjacent SFF
     quaternions. These manufactured rates were verified to be close to
     the actual rates when the two data streams were merged together.
 
 
Approximate Time Coverage
--------------------------------------------------------
 
     This file covers the following time span, UTC:
 
          START_TIME = 2004-12-31T23:53:50.189
          STOP_TIME  = 2006-01-29T23:59:25.724
 
     This file is a type 3 CK file (segment) which provides linear
     interpolation between orientation data points. Such interpolation
     is not applied between segments. Within a segment the
     interpolation is applied only inside intervals where enough
     orientation telemetry data was available and orientation data
     points were close to each other in time for such interpolation to
     make sense.
 
     To obtain the complete list of valid interpolation intervals for
     each of the file segments, use SPICE Toolkit's CKBRIEF utility
     program with "-dump" command line option.
 
     To modify interpolation interval information stored in the file
     segment, use CKSPANIT utility program. CKSPANIT is not a part of
     the generic SPICE Toolkit but it is one of the NAIF supported tools
     distributed by special request.
 
 
Usage Note
--------------------------------------------------------
 
     In order to use this file an SDU SCLK file, containing
     coefficients mapping SDU on-board time to ET, and standard LSK
     file, providing UTC to ET mapping, must be loaded into a user's
     program.
 
 
Contacts
--------------------------------------------------------
 
     If you have any question regarding this data contact NAIF at JPL:
 
        Boris V. Semenov
        (818)-354-8136
        boris.semenov@jpl.nasa.gov
 
 
MSOPCK Setup Information
--------------------------------------------------------
 
 
 
********************************************************************************
MSOPCK SETUP FILE: sdu_sc_rec_2XXX_v2.msopck
********************************************************************************
 
\begindata
 
PRODUCER_ID             = 'NAIF/JPL'
 
LSK_FILE_NAME           = 'naif0008.tls'
SCLK_FILE_NAME          = 'SD_SCLKSCET.00141.tsc'
INTERNAL_FILE_NAME      = 'SDU SC ATT.; CHTLM AND SFF MERGED; NAIF/JPL'
 
CK_TYPE                 = 3
CK_SEGMENT_ID           = 'SDU SC BUS ATT.; CHTLM+SFF MERGED'
INSTRUMENT_ID           = -29000
REFERENCE_FRAME_NAME    = 'J2000'
ANGULAR_RATE_PRESENT    = 'YES'
ANGULAR_RATE_FRAME      = 'REFERENCE'
 
INPUT_DATA_TYPE         = 'SPICE QUATERNIONS'
INPUT_TIME_TYPE         = 'TICKS'
 
MAXIMUM_VALID_INTERVAL  = 60
QUATERNION_NORM_ERROR   = 1.0E-3
 
\begintext
 
********************************************************************************
RUN-TIME OBTAINED META INFORMATION:
********************************************************************************
 
PRODUCT_CREATION_TIME = 2006-02-02T11:49:11
START_TIME            = 2004-12-31T23:53:50.189
STOP_TIME             = 2006-01-29T23:59:25.724
 
 
