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  http://pds.nasa.gov/pds4/mission/mess/v1 https://pds.nasa.gov/pds4/mission/mess/v1/PDS4_MESS_1B00_1020.xsd">
  <Identification_Area>
    <logical_identifier>urn:nasa:pds:mess_rs_derived:data:ggmes_100v07_sha</logical_identifier>
    <version_id>1.0</version_id>
    <title>MESSENGER Spherical Harmonic Gravity Model product: ggmes_100v07_sha</title>
    <information_model_version>1.11.0.0</information_model_version>
    <product_class>Product_Observational</product_class>
    <Modification_History>
      <Modification_Detail>
        <modification_date>2018-07-02</modification_date>
        <version_id>1.0</version_id>
        <description>PDS4 migrated product.</description>
      </Modification_Detail>
    </Modification_History>
  </Identification_Area>
  <Observation_Area>
    <Time_Coordinates>
      <start_date_time>2008-01-07Z</start_date_time>
      <stop_date_time>2015-04-30Z</stop_date_time>
    </Time_Coordinates>
    <Investigation_Area>
      <name>MESSENGER</name>
      <type>Mission</type>
      <Internal_Reference>
        <lid_reference>urn:nasa:pds:context:investigation:mission.messenger</lid_reference>
        <reference_type>data_to_investigation</reference_type>
      </Internal_Reference>
    </Investigation_Area>
    <Observing_System>
      <Observing_System_Component>
        <name>MESSENGER</name>
        <type>Spacecraft</type>
        <Internal_Reference>
          <lid_reference>urn:nasa:pds:context:instrument_host:spacecraft.mess</lid_reference>
          <reference_type>is_instrument_host</reference_type>
        </Internal_Reference>
      </Observing_System_Component>
      <Observing_System_Component>
        <name>Radio Science Subsystem</name>
        <type>Instrument</type>
        <Internal_Reference>
          <lid_reference>urn:nasa:pds:context:instrument:rss.mess</lid_reference>
          <reference_type>is_instrument</reference_type>
        </Internal_Reference>
      </Observing_System_Component>
    </Observing_System>
    <Target_Identification>
      <name>Mercury</name>
      <type>Planet</type>
      <Internal_Reference>
        <lid_reference>urn:nasa:pds:context:target:planet.mercury</lid_reference>
        <reference_type>data_to_target</reference_type>
      </Internal_Reference>
    </Target_Identification>
    <Mission_Area>
      <mess:MESSENGER>
        <mess:standard_data_product_id>SHADR</mess:standard_data_product_id>
        <mess:software_name>Nsolve</mess:software_name>
      </mess:MESSENGER>
    </Mission_Area>
  </Observation_Area>
  <Reference_List>
    <External_Reference>
      <reference_text>Mazarico, E., A. Genova, S. Goossens, F.G. Lemoine, D.E. Smith, M.T.
        Zuber, G.A. Neumann, and S.C. Solomon, The gravity field of Mercury
        after MESSENGER, Lunar and Planetary Science Conference, no. 47, pp.
        2022, Lunar and Planetary Institute, Universities Space Research
        Association, Houston, TX., March 2016.</reference_text>
    </External_Reference>
  </Reference_List>
  <File_Area_Observational>
    <File>
      <file_name>ggmes_100v07_sha.tab</file_name>
      <creation_date_time>2016-01-22</creation_date_time>
      <comment>
        This product contains coefficients and related data for a spherical harmonic model
        of the Hermean gravity field. Input data are from radio tracking of the MErcury
        Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft.
        This product is a set of ASCII tables: a header table and a coefficients table.
        Definitions of the tables follow. This MESSENGER Mercury gravity model is in the
        form of a Spherical Harmonics Ascii Data Record (SHADR). It has been produced by
        the MESSENGER Radio Science at NASA GSFC, and extends to degree and order 50.
        A Kaula rule of 3.0E-05/L^2 was applied. All the MESSENGER tracking data, up to 
        the end of mission (April 30, 2015) are included in this solution.
        
        The Mercury orientation was chosen to follow the parameters adopted by the
        MESSENGER project for the final PDS delivery, as described in the SPICE PCK
        kernel 'pck00010_msgr_v21.tpc'. The pole orientation, prime meridian, and 
        spin period were not adjusted during the gravity solution.
        
        Reference radius = 2439.4 km
        
        Pole orientation (right ascension and declination at J2000):
        RA = 281.01030 degree
        DEC =  61.41556 degree
        
        Prime meridian = 329.5988 degrees (at J2000)
        Spin rate = 6.1385108 degrees/day.
        
        The citation for this model is Mazarico et al., 2016.
      </comment>
    </File>
    <Table_Character>
      <name>SHADR Header Table</name>
      <offset unit="byte">0</offset>
      <records>1</records>
      <description>The SHADR header includes descriptive
        information about the spherical harmonic coefficients that follow in
        SHADRCoefficients Table. The header consists of a single record of eight
        (delimited) data columns requiring 137 bytes, a pad of 105 unspecified ASCII
        characters, an ASCII carriage-return, and an ASCII line-feed.</description>
      <record_delimiter>Carriage-Return Line-Feed</record_delimiter>
      <Record_Character>
        <fields>8</fields>
        <groups>0</groups>
        <record_length unit="byte">244</record_length>
        <Field_Character>
          <name>reference radius</name>
          <field_number>1</field_number>
          <field_location unit="byte">1</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <unit>km</unit>
          <description>The assumed reference radius of the spherical planet.</description>
        </Field_Character>
        <Field_Character>
          <name>constant</name>
          <field_number>2</field_number>
          <field_location unit="byte">25</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <description>For a gravity field model the assumed
            gravitational constant GM in km cubed per second squared for the
            planet. For a topography model, set to 1.</description>
        </Field_Character>
        <Field_Character>
          <name>uncertainty in constant</name>
          <field_number>3</field_number>
          <field_location unit="byte">49</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <description>For a gravity field model the
            uncertainty in the gravitational constant GM in km cubed per second
            squared for the planet (or, set to 0 if not known). For a topography
            model, set to 0.</description>
        </Field_Character>
        <Field_Character>
          <name>degree of field</name>
          <field_number>4</field_number>
          <field_location unit="byte">73</field_location>
          <data_type>ASCII_Integer</data_type>
          <field_length unit="byte">5</field_length>
          <description>Degree of the model field.</description>
        </Field_Character>
        <Field_Character>
          <name>order of field</name>
          <field_number>5</field_number>
          <field_location unit="byte">79</field_location>
          <data_type>ASCII_Integer</data_type>
          <field_length unit="byte">5</field_length>
          <description>Order of the model field.</description>
        </Field_Character>
        <Field_Character>
          <name>normalization state</name>
          <field_number>6</field_number>
          <field_location unit="byte">85</field_location>
          <data_type>ASCII_Integer</data_type>
          <field_length unit="byte">5</field_length>
          <description>The normalization indicator.
            For gravity field:
            0   coefficients are unnormalized
            1   coefficients are normalized
            2   other.
          </description>
        </Field_Character>
        <Field_Character>
          <name>reference longitude</name>
          <field_number>7</field_number>
          <field_location unit="byte">91</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <unit>degree</unit>
          <description>The reference longitude for the
            spherical harmonic expansion; normally 0.</description>
        </Field_Character>
        <Field_Character>
          <name>reference latitude</name>
          <field_number>8</field_number>
          <field_location unit="byte">115</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <unit>degree</unit>
          <description>The reference latitude for the
            spherical harmonic expansion; normally 0.</description>
        </Field_Character>
      </Record_Character>
    </Table_Character>
    <Table_Character>
      <name>SHADR Coefficients Table</name>
      <offset unit="byte">244</offset>
      <records>5150</records>
      <description>The SHADR coefficients table contains the
        coefficients for the spherical harmonic model. Each row in the table
        contains the degree index m, the order index n, the coefficients Cmn and
        Smn, and the uncertainties in Cmn and Smn. The (delimited) data require
        107 ASCII characters; these are followed by a pad of 13 unspecified ASCII
        characters, an ASCII carriage-return, and an ASCII line-feed.
      </description>
      <record_delimiter>Carriage-Return Line-Feed</record_delimiter>
      <Record_Character>
        <fields>6</fields>
        <groups>0</groups>
        <record_length unit="byte">122</record_length>
        <Field_Character>
          <name>coefficient degree</name>
          <field_number>1</field_number>
          <field_location unit="byte">1</field_location>
          <data_type>ASCII_Integer</data_type>
          <field_length unit="byte">5</field_length>
          <description>Degree index m of the C and S coefficients in this record.</description>
        </Field_Character>
        <Field_Character>
          <name>coefficient order</name>
          <field_number>2</field_number>
          <field_location unit="byte">7</field_location>
          <data_type>ASCII_Integer</data_type>
          <field_length unit="byte">5</field_length>
          <description>Order index n of the C and S coefficients in this record.</description>
        </Field_Character>
        <Field_Character>
          <name>c</name>
          <field_number>3</field_number>
          <field_location unit="byte">13</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <description>Coefficient Cmn for this spherical harmonic model.</description>
        </Field_Character>
        <Field_Character>
          <name>s</name>
          <field_number>4</field_number>
          <field_location unit="byte">37</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <description>Coefficient Smn for this spherical harmonic model.</description>
        </Field_Character>
        <Field_Character>
          <name>c uncertainty</name>
          <field_number>5</field_number>
          <field_location unit="byte">61</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <description>Uncertainty in the coefficient Cmn for this spherical harmonic model.</description>
        </Field_Character>
        <Field_Character>
          <name>s uncertainty</name>
          <field_number>6</field_number>
          <field_location unit="byte">85</field_location>
          <data_type>ASCII_Real</data_type>
          <field_length unit="byte">23</field_length>
          <description>Uncertainty in the coefficient Smn for this spherical harmonic model.</description>
        </Field_Character>
      </Record_Character>
    </Table_Character>
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      <file_name>ggmes_100v07_sha.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>
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