PDS_VERSION_ID          = PDS3                                               
LABEL_REVISION_NOTE     = "2013-12-13, Initial"                              
RECORD_TYPE             = STREAM                                             
OBJECT                  = TEXT                                               
  PUBLICATION_DATE      = 2013-12-13                                       
  NOTE                  = "Description of the CALIB directory contents 
                           for the MSL Engineering Camera Archive"
END_OBJECT              = TEXT                                               
END                                                                          


                     CALIB Directory Contents              
                                                                  
The CALIB directory contains numerous files that are used to
interpret and process the MSL camera data.  Detailed descriptions are
beyond the scope of this document, but an overview is presented below.

CALINFO.TXT        - The file you are reading.

README.TXT         - Release notes for the directory contents. The file
                     is a record of changes made during development and
                     operations, and is provided for historical context.

There are several subdirectories within the CALIB directory.  Each
is discussed below, along with its contents.  Note: there is no calibration
report available for the MSL Engineering cameras.  However, application of 
the calibration files is described in Section 5 of the MSL_CAMERA_SIS.PDF,
located in the DOCUMENTS directory of this archive volume.


CAMERA_MODELS subdirectory:
This directory contains the CAHV-style calibration camera models for
each camera.  These are the camera models derived from ATLO testing that
are valid when the camera head is pointed according to the
rsm_calibration_position/quaternion in the point file (see below).  They
are then transformed based on the camera pointing to create the final
camera model.

The files with _CAL_ in the names are the calibration models as
delivered by the operations team (and correspond to the models that are
uplinked to the rover).  The CAL number is a version (so all delivered
versions are here).  The files starting with MSL_SN contain the 
currently active model (as of the date of archive release) for each camera.  
The serial numbers in these filenames are referenced to the camera mapping 
file (see below).

In addition to the CAHV(ORE) vectors, these files contain the covariance
matrix from the calibration process and internal camera parameters
derived from the CAHV(ORE) vectors.


FLAT_FIELDS subdirectory:
This directory contains flat field images for each camera.  The serial
numbers are referenced to the camera mapping file.  Each image is
divided by the appropriate flat field as part of the radiometric
calibration process. See Section 5.2.1.2.2 (MIPLRAD Method) of the 
Camera SIS for more information.


ILUT subdirectory:
This directory contains the inverse lookup tables used to create the ILT
products.  The first number on each line is the 0-255 compressed value
as seen in telemetry; the second is the 0-4095 original DN value. See
Section 5.2.1.1 (Inverse LUT RDR) of the Camera SIS for more information.


PARAM_FILES subdirectory:
This directory contains miscellaneous parameter files. Each file type
is described below.

MSL_camera_mapping.xml:  This XML file contains basic information about
each camera: its serial number, size, name, stereo partner, whether it
has focus or filters, etc.

MSL_filter_exclude.txt:  This text file contains a list of "objects" from
the flight software volumetric model that are excluded when computing
the rover mask.  This file is unlikely to be useful without access to
the flight software model, which is not part of the PDS delivery.

MSL_mast.point:  This text file contains parameters for the RSM mast,
which are used for all mast-mounted cameras.  This includes mast
kinematics parameters (some description is provided in comments, and in
the SIS, but the full kinematics algorithm is beyond the scope of this
document).  These parameters are copies of what is uplinked to the
vehicle (so that ground-computed models match exactly flight-computed
models).  It also contains the calibration position and quaternion for
the RSM for all of the calibration camera models (all cameras share the
same calibration pointing), the translation between the RMECH and RNAV
coordinate systems, and default parameters for pointing correction.

MSL_rover_filter.xml:  This XML file contains filter parameters for the
rover mask.  These filters are in addition to the volumetric model
provided by the flight software for computing the rover mask.  Although
this file was quite important for MER, the volumetric model has almost
completely replaced it on MSL.

MSL_flat_fields.parms:  This text file contains responsivity parameters
used by the MIPLRAD radiometric correction process for all cameras
(flight as well as testbed), as described in the SIS.  The three values
represent a quadratic based on temperature (t^0, t^1, t^2).