 
 
M01 High Gain Antenna Orientation CK File for Mapping, 2004-01 ... 2004-03
===========================================================================
 
     Created by Boris Semenov, NAIF/JPL, Wed May 12 11:26:46 PDT 2004
 
 
Orientation Data in the File
--------------------------------------------------------
 
     This file contains orientation and angular rate data for the Mars'01
     Odyssey (M01) High Gain Antenna (HGA) Inner and Outer gimbal frames.
     The orientation of the 'M01_HGA_INNER_GIMBAL' is given with respect to
     the 'M01_HGA_BOOM' frame; orientation of the 'M01_HGA_OUTER_GIMBAL' is
     given with respect to the 'M01_HGA_INNER_GIMBAL' frame. The NAIF IDs
     for the 'M01_HGA_INNER_GIMBAL' and 'M01_HGA_OUTER_GIMBAL' frames are
     -53211 and -53212.
 
 
Status
--------------------------------------------------------
 
     This file was created by NAIF for archiving with the Planetary Data
     System (PDS) from daily CK files produced by NAIF, JPL.
 
 
Pedigree
--------------------------------------------------------
 
     The original CK files used to create this file were officially
     delivered to the M01 project by the NAIF Team. These files contained
     the inner gimbal frame orientation with respect to the HGA boom frame
     and the outer gimbal frame orientation with respect to the inner
     gimbal frame. The orientation was computed on the ground from the HGA
     gimbal angles extracted from the channelized telemetry sent down by
     the spacecraft. The individual daily CK files were merged together to
     provide coverage for a complete or a portion of a particular phase of
     the mission.
 
     A table containing the complete list of original CK files from which
     data were included in this file is provided at the end of these
     comments.
 
 
Approximate Time Coverage
--------------------------------------------------------
 
     This file covers the following interval of the Mapping phase of the
     mission:
 
          Coverage Begin UTC       Coverage End UTC
          ------------------------ ------------------------
          2004-JAN-01 00:06:29.592 2004-MAR-31 23:59:23.632
 
     This file is a type 3 CK file which provides linear interpolation
     between orientation data points extracted from telemetry. Such
     interpolation is not applied to the whole coverage of the file but
     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.
 
     The nominal gimbal angle time spacing in the telemetry stream varied
     from one to a few seconds between adjacent data points. Considering
     that the antenna gimbal cannot rotate very fast and that the highest
     accuracy of the HGA orientation knowledge is unlikely to be needed in
     any application, the duration of the longest interval over which the
     data may be interpolated was set to 300 seconds. For all requests for
     data falling between two adjacent data points separated by more than
     300 seconds the SPICELIB CK readers will return a logical flag
     stating "POINTING NOT FOUND".
 
     A table containing the complete list of valid interpolation intervals
     in the file segments is provided at the end of these comments.
 
 
Angular Rate Data Note
--------------------------------------------------------
 
     Since M01 s/c engineering telemetry did not contain angular rate data
     for the gimbal, the angular rates stored in this file were computed
     from the orientation information. The angular rate for each
     orientation point was computed as average of two rates -- constant
     angular rate that would rotate from previous point to that point and
     constant angular rate that would rotate from that point to the next
     point.
 
     Because angular rates stored in two adjacent points in most cases are
     not the same, and CK readers linearly interpolate between them, the
     output angular rates in general will never be constant between any two
     adjacent data points stored in the file.
 
 
Usage Note
--------------------------------------------------------
 
     In order to use this file an M01 SCLK file containing coefficients
     mapping M01 on-board time to ET must be loaded into a user's program.
 
     Loading an M01 Frames Kernel (FK) containing information that SPICE
     software need to combine gimbal orientations together will allow a
     user to get the combined orientation through the high level SPICE
     Toolkit interfaces.
 
 
Related Kernels
--------------------------------------------------------
 
     This file was created using the following LSK and SCLK files:
 
        naif0007.tls
        ORB1_SCLKSCET.00083.tsc
 
 
Contacts
--------------------------------------------------------
 
     If you have any question regarding this data contact NAIF at JPL:
 
        Charles H. Acton, Jr
        (818)-354-3869
        chuck.acton@jpl.nasa.gov
 
        Boris V. Semenov
        (818)-354-8136
        boris.semenov@jpl.nasa.gov
 
 
Appendix 1: List of the original CK files
--------------------------------------------------------
 
m01_hga_2004-01-01.bc
m01_hga_2004-01-02.bc

(many lines were skipped here to reduce the example size)

m01_hga_2004-03-30.bc
m01_hga_2004-03-31.bc
 
 
Appendix 2: Interpolation Intervals in the File
--------------------------------------------------------
 
     The information in this section has been generated by running CKBRIEF
     utility program using -dump -utc command line options.
 
 
CKBRIEF Version: 2.0.0, 2001-05-16. SPICE Toolkit Version: N0057.
 
 
Summary for: m01_hga_map9.bc
 
Segment No.: 1
 
Object:  -53211
  Interval Begin UTC       Interval End UTC         AV
  ------------------------ ------------------------ ---
  2004-JAN-01 00:06:29.592 2004-JAN-03 20:11:10.790 Y
  2004-JAN-03 20:38:38.783 2004-JAN-06 03:36:23.198 Y

  (many lines were skipped here to reduce the example size)

  2004-MAR-29 10:24:29.216 2004-MAR-31 09:23:49.287 Y
  2004-MAR-31 09:35:23.997 2004-MAR-31 23:59:23.632 Y
 
 
