Filling out the Image Display Geometry Class

The <Image_Display_Geometry> class maps the orientation of cardinal directions (North and East, typically) to an image-like data object based on that image being displayed on a device according to the display settings in the label (defined in the Display Discipline Dictionary <Display_Direction> class).

<Display_Direction>

OPTIONAL

If you are providing orientation information for a data object, you must have a corresponding Display_Direction class either here or as part of a <Display_Settings> from the Display Discipline Dictionary. Don't provide the same information twice, though - it opens up the opportunity for conflict and error. This class is filled out the same way whether it appears in here or in the <Display_Settings> class from the Display Discipline Dictionary in terms of attribute content. See Filling Out the Display_Dictionary Classes: Display_Direction for details.

If you are going to use the version that in included inside this <Image_Geometry_Class>, though, you are going to need to specify the Display Dictionary namespace (standard abbreviation is "disp") for the attributes inside the Display_Direction class, but not for the Display_Direction tag itself, which in this class is considered part of the Geometry Dictionary namespace. You can do this either by defining and using the standard disp: prefix with all the tags inside this class, or you can provide an explicit reference to the Display Dictionary namespace by using the xmlns XML attribute in your tags. If that all sounds like gibberish to you, you might want to check the Namespace Reference topic on the "Schema Referencing" page on this wiki.

If you use the disp: prefix on your tags, for example, then they will look like this:

    <Display_Direction>
      <disp:comment>...</disp:comment>
      <disp:horizontal_display_axis>...</disp:horizontal_display_axis>
      <disp:horizontal_display_direction>...</disp:horizontal_display_direction>
      <disp:vertical_display_axis>...</disp:vertical_display_axis>
      <disp:vertical_display_direction>...</disp:vertical_display_direction>
    </Display_Direction>

<Object_Orientation_North_East>

OPTIONAL

One of either this class or <Object_Orientation_RA_Dec> must be included. You may also repeat this class (or that one) multiple times.

<north_azimuth>

REQUIRED

<east_azimuth>

REQUIRED

<Reference_Frame_Identification>

REQUIRED

<body_spice_name>

OPTIONAL

<body_spice_id>

OPTIONAL

<frame_space_name>

OPTIONAL

<frame_spice_id>

OPTIONAL

<name>

OPTIONAL

<Internal_Reference>

OPTIONAL

<Local_Internal_Reference>

OPTIONAL

<pds:comment>

OPTIONAL

<pds:local_identifier_reference>

REQUIRED

<pds:local_reference_type>

REQUIRED

<Object_Orientation_RA_Dec>

OPTIONAL

One of either this class or <Object_Orientation_North_East> must be included. You may also repeat this class (or that one) multiple times.

<geometry_reference_time>

REQUIRED

<Reference_Pixel>

OPTIONAL

<vertical_coordinate_pixel>

REQUIRED

<horizontal_coordinate_pixel>

REQUIRED

<reference_pixel_location>

OPTIONAL

<right_ascension_hour_angle> or <right_ascension_angle>

REQUIRED

<declination_angle>

REQUIRED

<celestial_north_clock_angle>

OPTIONAL

At least one of celestial_north_clock_angle and ecliptic_north_clock_angle must be provided. You may include both.

<ecliptic_north_clock_angle>

OPTIONAL

At least one of celestial_north_clock_angle and ecliptic_north_clock_angle must be provided. You may include both.

<Reference_Frame_Identification>

REQUIRED

This class is the same here as in the <Object_Orientation_North_East> class, described above.

<Quaternion_SPICE_Style>

OPTIONAL

<qcos>

REQUIRED

<qsin1>

REQUIRED

<qsin2>

REQUIRED

<qsin3>

REQUIRED

<Quaternion_non_SPICE_Style>

OPTIONAL

<qsin1>

REQUIRED

<qsin2>

REQUIRED

<qsin3>

REQUIRED

<qcos>

REQUIRED

<Object_Orientation_Clock_Angles>

OPTIONAL

<celestial_north_clock_angle>

OPTIONAL

<ecliptic_north_clock_angle>

OPTIONAL

<central_body_north_pole_clock_angle>

OPTIONAL

<target_north_pole_clock_angle>

OPTIONAL

<target_positive_pole_clock_angle>

OPTIONAL

<body_positive_pole_clock_angle>

OPTIONAL

<sun_direction_clock_angle>

OPTIONAL

<Reference_Frame_Identification>

REQUIRED

This class is the same here as in the <Object_Orientation_North_East> class, described above.