MRO MCS Orientation CK File for REPPHASE phase, REPMONTH
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     Created on REPDATE.
    

Orientation Data in the File
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     This file contains actual orientation data for the Mars
     Reconnaissance Orbiter (MRO) Mars Climate Sounder (MCS)
     instrument. It provides orientation for the MCS's azimuth and
     elevation gimbal frames. The orientation of the ``MRO_MCS_AZ_GIMBAL''
     frame (frame ID -74503) is given with respect to the
     ``MRO_MCS_AZ_GIMBAL_REF'' frame (frame ID -74502) while the
     orientation of the ``MRO_MCS_EL_GIMBAL'' frame (frame ID -74505)
     is given with respect to the ``MRO_MCS_EL_GIMBAL_REF'' frame
     (frame ID -74504).


Status
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     This file was created by NAIF by merging daily MCS CK files
     generated by the MCS Team. This file is intended for archiving
     with the Planetary Data System (PDS).


Pedigree
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     The original daily CK files used to create this file were made
     during operations by the MCS Team. These files contained
     orientation of the gimbal frames computed using commanded gimbal
     angles from the instrument's housekeeping telemetry. On the ground
     the angles were extracted from telemetry, converted from actuator
     steps to degrees and recorded in the Level 1A EDR tables used
     internally by the MCS team. Then another process extracted angles
     from the tables, computed applicable start and stop times for each
     pair of angles by expanding the applicable record's time into a
     2.05 second window, adjusted the angles to match the MCS frame
     convention defined in the FK by subtracting 180 degrees from
     azimuth and subtracting elevation from 90 degrees, converted
     angles to rotation matrices assuming rotation by adjusted azimuth
     about Z and rotation by adjusted elevation about Y, converted
     matrices to quaternions and recorded quaternions augmented by zero
     angular rates to two separate type 2 CK segments -- one for the
     azimuth rotation and the other for the elevation rotation -- in
     the same CK file.
 
     Only the angles for the Level 1A EDR records for which the
     instrument was not moving were used in creating daily CK files. In
     the Level 1A tables the angles from a given record (provided in
     ``Last_az_cmd'' and ``Last_el_cmd'' fields) applied to the next
     data record. This was taken into account when applicable start and
     stop times for each pair of angles were determined.
 
     At the time of archive preparation the MCS team provided MCS CK
     daily files to NAIF. These files were merged together using DAFCAT
     and augmented with these comments (see Appendix 1 for the complete
     list of original daily files used to make this file).


Approximate Time Coverage
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     This file covers the following interval of the REPPHASE phase 
     of the mission:

          Coverage Begin UTC       Coverage End UTC
          ------------------------ ------------------------
          REPCOVER

     This file is a type 2 CK file which contains sets of ~2.05 seconds
     intervals for each of the instrument soundings during which the
     instrument was not moving. During each of these intervals the
     orientation is constant; between the intervals the orientation is
     not available.

     To see the complete list of interval for which this CK file
     provides orientation data use the CK summary utility ``CKBRIEF''
     with ``-dump'' option.
  

Usage Note
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     In order to use this file an LSK file and an MRO SCLK file
     containing coefficients mapping MRO on-board clock (ID -74) to ET
     must be loaded into a user's program. Since this CK file provides
     orientation for two of many frames in the MCS frame chain it is
     also recommended that you load the latest MRO FK file.
 

Contacts
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     If you have any questions regarding this data contact MCS Team:

        Tim Schofield
        (818)-354-2517
        John.T.Schofield@jpl.nasa.gov

     or NAIF:

        Boris V. Semenov
        (818)-354-8136
        boris.semenov@jpl.nasa.gov


Appendix 1: List of the original CK files
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