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<Product_Observational xmlns="http://pds.nasa.gov/pds4/pds/v1" 
  xmlns:pds="http://pds.nasa.gov/pds4/pds/v1" 
  xmlns:cart="http://pds.nasa.gov/pds4/cart/v1" 
  xmlns:disp="http://pds.nasa.gov/pds4/disp/v1" 
  xmlns:geom="http://pds.nasa.gov/pds4/geom/v1"
  xmlns:msn="http://pds.nasa.gov/pds4/msn/v1"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:schemaLocation="http://pds.nasa.gov/pds4/pds/v1 https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1N00.xsd http://pds.nasa.gov/pds4/cart/v1 https://pds.nasa.gov/pds4/cart/v1/PDS4_CART_1N00_1970.xsd 
  http://pds.nasa.gov/pds4/disp/v1 https://pds.nasa.gov/pds4/disp/v1/PDS4_DISP_1N00_1510.xsd
  http://pds.nasa.gov/pds4/geom/v1 https://pds.nasa.gov/pds4/geom/v1/PDS4_GEOM_1N00_1980.xsd
  http://pds.nasa.gov/pds4/msn/v1 https://pds.nasa.gov/pds4/msn/v1/PDS4_MSN_1N00_1310.xsd">
  
  <Identification_Area>
    <logical_identifier>urn:nasa:pds:mgs_mola_topography_derived:data_meg032:megr90n000fb</logical_identifier>
    <version_id>1.0</version_id>
    <title>MGS MOLA MEGDR product: megr90n000fb</title>
    <information_model_version>1.23.0.0</information_model_version>
    <product_class>Product_Observational</product_class>
    <Citation_Information>
      <publication_year>2026</publication_year>
      <description>This data product is a shape map of Mars at a resolution of 0.03125 (1/32) by 0.03125 degrees, based on altimetry data acquired by the Mars Global Surveyor MOLA instrument</description>
      <List_Author>
        <Person>
          <contributor_type>Producer</contributor_type>
          <given_name>David E.</given_name>
          <family_name>Smith</family_name>
          <Affiliation>
            <organization_name>Goddard Space Flight Center, MOLA Team</organization_name>
          </Affiliation>
        </Person>
        <Person>
          <contributor_type>DataCurator</contributor_type>
          <given_name>Madison N.</given_name>
          <family_name>Hughes</family_name>
          <Affiliation>
            <organization_name>Washington University in St. Louis</organization_name>
          </Affiliation>
        </Person>
      </List_Author>
    </Citation_Information>
    <Modification_History>
      <Modification_Detail>
        <modification_date>2026-08-25</modification_date>
        <version_id>1.0</version_id>
        <description>Initial PDS4 version</description>
      </Modification_Detail>
    </Modification_History>
  </Identification_Area>
  <Observation_Area>
    <Time_Coordinates>
      <start_date_time>1997-09-15T19:10:00.000Z</start_date_time>
      <stop_date_time>2001-06-30T11:10:40.000Z</stop_date_time>
    </Time_Coordinates>
    <Investigation_Area>
      <name>Mars Global Surveyor</name>
      <type>Mission</type>
      <Internal_Reference>
        <lid_reference>urn:nasa:pds:context:investigation:mission.mars_global_surveyor</lid_reference>
        <reference_type>data_to_investigation</reference_type>
      </Internal_Reference>
    </Investigation_Area>
    <Observing_System>
      <name>MOLA</name>
      <Observing_System_Component>
        <name>The Mars Global Surveyor Spacecraft</name>
        <type>Host</type>
        <Internal_Reference>
          <lid_reference>urn:nasa:pds:context:instrument_host:spacecraft.mgs</lid_reference>
          <reference_type>is_instrument_host</reference_type>
        </Internal_Reference>
      </Observing_System_Component>
      <Observing_System_Component>
        <name>Mars Global Surveyor Spacecraft Mars Orbiter Laser Altimeter</name>
        <type>Instrument</type>
        <Internal_Reference>
          <lid_reference>urn:nasa:pds:context:instrument:mgs.mola</lid_reference>
          <reference_type>is_instrument</reference_type>
        </Internal_Reference>
      </Observing_System_Component>
    </Observing_System>
    <Target_Identification>
      <name>Mars</name>
      <type>Planet</type>
      <Internal_Reference>
        <lid_reference>urn:nasa:pds:context:target:planet.mars</lid_reference>
        <reference_type>data_to_target</reference_type>
      </Internal_Reference>
    </Target_Identification>
    <Mission_Area>
      <msn:Mission_Information>
        <msn:Orbital_Mission>
          <msn:start_orbit_number>3</msn:start_orbit_number>
          <msn:stop_orbit_number>20333</msn:stop_orbit_number>
        </msn:Orbital_Mission>
      </msn:Mission_Information>
    </Mission_Area>
    <Discipline_Area>  
      <cart:Cartography>
        <Local_Internal_Reference>
          <local_identifier_reference>gridded_image</local_identifier_reference>
          <local_reference_type>cartography_parameters_to_image_object</local_reference_type>
        </Local_Internal_Reference>
        <cart:Spatial_Domain>
          <cart:Bounding_Coordinates>
            <cart:west_bounding_coordinate unit="deg">0</cart:west_bounding_coordinate>
            <cart:east_bounding_coordinate unit="deg">360</cart:east_bounding_coordinate>
            <cart:north_bounding_coordinate unit="deg">90</cart:north_bounding_coordinate>
            <cart:south_bounding_coordinate unit="deg">-90</cart:south_bounding_coordinate>
          </cart:Bounding_Coordinates>
        </cart:Spatial_Domain>
        <cart:Spatial_Reference_Information>
          <cart:Horizontal_Coordinate_System_Definition>
            <cart:Planar>
              <cart:Map_Projection>
                <cart:map_projection_name>Equirectangular</cart:map_projection_name>
                <cart:Equirectangular>
                  <cart:standard_parallel_1 unit="deg">0.</cart:standard_parallel_1>
                  <cart:longitude_of_central_meridian unit="deg">180.</cart:longitude_of_central_meridian>
                </cart:Equirectangular>
              </cart:Map_Projection>
              <cart:Planar_Coordinate_Information>
                <cart:planar_coordinate_encoding_method>Coordinate Pair</cart:planar_coordinate_encoding_method>
                <cart:Coordinate_Representation>
                  <cart:pixel_resolution_x unit="km/pixel">32</cart:pixel_resolution_x>
                  <cart:pixel_resolution_y unit="km/pixel">32</cart:pixel_resolution_y>
                  <cart:pixel_scale_x unit="pixel/deg">1.853</cart:pixel_scale_x>
                  <cart:pixel_scale_y unit="pixel/deg">1.853</cart:pixel_scale_y>
                </cart:Coordinate_Representation>
              </cart:Planar_Coordinate_Information>
              <cart:Geo_Transformation>
                <cart:upperleft_corner_x unit="m">-10673280</cart:upperleft_corner_x>
                <cart:upperleft_corner_y unit="m">5336640</cart:upperleft_corner_y>
              </cart:Geo_Transformation>
            </cart:Planar>
            <cart:Geodetic_Model>
              <cart:latitude_type>Planetocentric</cart:latitude_type>
              <cart:a_axis_radius unit="km">3396.0</cart:a_axis_radius>
              <cart:b_axis_radius unit="km">3396.0</cart:b_axis_radius>
              <cart:c_axis_radius unit="km">3396.0</cart:c_axis_radius>
              <cart:longitude_direction>Positive East</cart:longitude_direction>
              <cart:coordinate_system_type>Body-fixed Rotating</cart:coordinate_system_type>
              <cart:coordinate_system_name>PLANETOCENTRIC</cart:coordinate_system_name>
            </cart:Geodetic_Model>
          </cart:Horizontal_Coordinate_System_Definition>
        </cart:Spatial_Reference_Information>
      </cart:Cartography>
      <disp:Display_Settings>
        <Local_Internal_Reference>
          <local_identifier_reference>gridded_image</local_identifier_reference>
          <local_reference_type>display_settings_to_array</local_reference_type>
        </Local_Internal_Reference>
        <disp:Display_Direction>
          <disp:horizontal_display_axis>Sample</disp:horizontal_display_axis>
          <disp:horizontal_display_direction>Left to Right</disp:horizontal_display_direction>
          <disp:vertical_display_axis>Line</disp:vertical_display_axis>
          <disp:vertical_display_direction>Top to Bottom</disp:vertical_display_direction>
        </disp:Display_Direction>
      </disp:Display_Settings>
      <geom:Geometry>
        <geom:Geometry_Orbiter>
          <geom:geometry_reference_time_utc>1999-08-08T03:10:20.000Z</geom:geometry_reference_time_utc>
          <geom:geometry_start_time_utc>1997-09-15T19:10:00.000Z</geom:geometry_start_time_utc>
          <geom:geometry_stop_time_utc>2001-06-30T11:10:40.000Z</geom:geometry_stop_time_utc>
          <geom:Orbiter_Identification>
            <geom:Central_Body_Identification><geom:name>Mars</geom:name></geom:Central_Body_Identification>           
            <geom:Coordinate_System_Identification>
              <geom:coordinate_system_type>Planetocentric</geom:coordinate_system_type>
              <geom:Coordinate_System_Origin_Identification>
                <geom:name>Mars</geom:name>
              </geom:Coordinate_System_Origin_Identification>
              <geom:Reference_Frame_Identification>
                <geom:name>IAU2000_MARS</geom:name>
              </geom:Reference_Frame_Identification>
            </geom:Coordinate_System_Identification>
          </geom:Orbiter_Identification>
        </geom:Geometry_Orbiter>
      </geom:Geometry>
    </Discipline_Area>
  </Observation_Area>
  <Reference_List>
    <Internal_Reference>
      <lid_reference>urn:nasa:pds:mgs_mola_topography_derived:document:egdrsis</lid_reference>
      <reference_type>data_to_document</reference_type>
    </Internal_Reference>
    <Internal_Reference>
      <lid_reference>urn:nasa:pds:mgs_mola_topography_derived:document:mola_envi</lid_reference>
      <reference_type>data_to_document</reference_type>
    </Internal_Reference>
  </Reference_List>
  <File_Area_Observational>
    <File>
      <file_name>megr90n000fb.img</file_name>
      <creation_date_time>2003-04-11T01:00:00</creation_date_time>
      <comment>This data product is a shape
 map of Mars at a resolution of 0.03125 (1/32) by 0.03125 degrees, based
 on altimetry data acquired by the Mars Global Surveyor MOLA instrument
 and accumulated over the course of the primary and extended
 mission. The MOLA Precision Experiment Data Records (PEDRs) are the
 source for this data set. The map is in the form of a binary table
 with one row for each 0.03125-degree latitude. Map coordinates use the
 IAU2000 reference system. The binned data include all MOLA nadir
 observations from the Mapping Phase through the Primary and Extended
 missions, from the end of aerobraking in February 1999 through June
 2001. Additionally, off-nadir observations of the north pole are
 included from 87 N latitude and northward, taken during the spring of
 1998, and of both poles taken during Mapping from 87 N and S to the
 poles. Data are adjusted using a first-order crossover solution for
 radial, along-track, and across-track position. Parts of orbits are
 excluded where solutions for these orbits are deemed to be
 poor. (Note: subtract 10000 from a MOLA mapping phase orbit number to
 determine the equivalent MGS Project orbit number.) Also excluded are
 shots more than 1.2 degree off-nadir (except as noted above), channel
 4 returns, and any returns not classified as ground returns,
 e.g. clouds or noise, according to the SHOT_CLASSIFICATION_CODE. A
 total of nearly 600,000,000 observations are represented.</comment>
    </File>
    <Array_2D_Image>
      <local_identifier>gridded_image</local_identifier>
      <offset unit="byte">0</offset>
      <axes>2</axes>
      <axis_index_order>Last Index Fastest</axis_index_order>
      <description>Each sample represents scaled
  mean planetary radius within a 0.03125 by 0.03125 degree area. Where no
  observations lie within the area, an interpolated value is supplied.
  Owing to the polar MGS orbit, density is lowest near the equator,
  where about 55% of bins contain at least one MOLA shot.  There are
  gaps, however, of up to 12 km between profiles.</description>
      <Element_Array>
        <data_type>SignedMSB2</data_type>
        <unit>meter</unit>
        <value_offset>3396000</value_offset>
      </Element_Array>
      <Axis_Array>
        <axis_name>Line</axis_name>
        <elements>5760</elements>
        <sequence_number>1</sequence_number>
      </Axis_Array>
      <Axis_Array>
        <axis_name>Sample</axis_name>
        <elements>11520</elements>
        <sequence_number>2</sequence_number>
      </Axis_Array>
    </Array_2D_Image>
  </File_Area_Observational>
  <File_Area_Observational_Supplemental>
    <File>
      <file_name>megr90n000fb.lbl</file_name>
    </File>
    <Stream_Text>
      <offset unit="byte">0</offset>
      <parsing_standard_id>PDS3</parsing_standard_id>
      <description>Original PDS3 label.</description>
      <record_delimiter>Carriage-Return Line-Feed</record_delimiter>
    </Stream_Text>
  </File_Area_Observational_Supplemental>
  <File_Area_Observational_Supplemental>
    <File>
      <file_name>megr90n000fb.hdr</file_name>
    </File>
    <Stream_Text>
      <offset unit="byte">0</offset>
      <parsing_standard_id>7-Bit ASCII Text</parsing_standard_id>
      <description> The ENVI header is a separate ASCII file that includes basic image data file characteristics. 
        ENVI will read both files and use the map projection information in the header file to correctly display
        the image. The header files are provided because ENVI is not able to import the map projection information 
        directly from the MEGDR image labels. 
      </description>
      <record_delimiter>Carriage-Return Line-Feed</record_delimiter>
    </Stream_Text>
  </File_Area_Observational_Supplemental>
</Product_Observational>
