<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<?xml-model href="https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1B00.sch"
  schematypens="http://purl.oclc.org/dsdl/schematron"?>
<?xml-model href="https://pds.nasa.gov/pds4/mission/mess/v1/PDS4_MESS_1B00_1020.sch"
  schematypens="http://purl.oclc.org/dsdl/schematron"?>

<Product_Observational xmlns="http://pds.nasa.gov/pds4/pds/v1" 
  xmlns:mess="http://pds.nasa.gov/pds4/mission/mess/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_1B00.xsd   
  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_100v08_sha</logical_identifier>
    <version_id>1.0</version_id>
    <title>MESSENGER Spherical Harmonic Gravity Model product: ggmes_100v08_sha</title>
    <information_model_version>1.11.0.0</information_model_version>
    <product_class>Product_Observational</product_class>
    <Modification_History>
      <Modification_Detail>
        <modification_date>2019-03-15</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>VCE</mess:software_name>
      </mess:MESSENGER>
    </Mission_Area>
  </Observation_Area>
  <Reference_List>
    <External_Reference>
      <doi>10.1029/2018GL081135</doi>
      <reference_text>Genova, A., S. Goossens, E. Mazarico, F.G. Lemoine, 
      G.A. Neumann, W. Kuang, T.J. Sabaka, S.A. Hauck, II, D.E. Smith, S.C. Solomon, and
      M.T. Zuber, Geodetic evidence that Mercury has a solid inner core,
      Geophysical Research Letters,, doi:10.1029/2018GL081135, 2019.</reference_text>
    </External_Reference>
  </Reference_List>
  <File_Area_Observational>
    <File>
      <file_name>ggmes_100v08_sha.tab</file_name>
      <creation_date_time>2016-01-22</creation_date_time>
      <comment>
      This file contains coefficient 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, a names table, a coefficients table, and a
      covariance 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 Team at NASA GSFC, and extends to degree
      and order 100. A Kaula rule of 4.0E-05/L^2 was applied.
      All the MESSENGER tracking data, up to the end of mission
      (April 30, 2015) are included in this solution.

      Reference radius = 2440.0 km.
      
      The pole orientation and spin period were
      adjusted during the gravity solution.

      Pole orientation (right ascension and declination at J2000):
      RA = 281.0082 degrees
      DEC =  61.4164 degrees
      Spin rate = 6.138505441 degrees/day .

      The prime meridian and secular terms in RA/DEC were not adjusted.
      Prime meridian = 329.7500 degrees (at J2000)
      RA rate = -0.0328 degree/century
      DEC rate = -0.0049 degree/century

      The citation for this model is GENOVAETAL2019.
      </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>
  </File_Area_Observational>
  <File_Area_Observational_Supplemental>
    <File>
      <file_name>ggmes_100v08_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>
    </Stream_Text>
  </File_Area_Observational_Supplemental>
</Product_Observational>
