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    <title>GRAIL Gravity ASCII Spherical Harmonic Model: GRGM1200A</title>
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      <file_name>gggrx_1200a_sha.tab</file_name>
      <creation_date_time>2016-03-01</creation_date_time>
      <comment>This file contains coefficients and related data for the GSFC Lunar gravity
 field GRGM1200A, a degree and order 1200 Spherical Harmonic Model. It is a
 preliminary GSFC gravity field that includes the entire GRAIL data set (and
 that does not include other data).

 Some details describing this model are:
   The spherical harmonic coefficients are fully normalized (geodesy 4pi
   normalized).
   The uncertainties are calibrated (the formal uncertainties multiplied by
   a factor of 1.635).
   The reference radius = 1738.0 km
   The gravitational parameter is GM = 4902.80011526323 km**3/s**2
   The planetary ephemeris is de430 and defines the lunar body-fixed
       coordinate system in the principal axes frame.
   A Kaula type power law constraint is applied to the spherical harmonics
       coefficients for degrees greater than 600 (3.6e-4/n^2).
   The weighting of the KBRR data is:
       0.03 microns/sec in the primary mission
       0.05 microns/sec in the extended mission
   The weighting of the DSN data is:
       0.12mm/s in both the primary and extended mission

 The nominal tidal Love number is k2 = 0.024133 +/- 0.000010


 The current best reference for the GRGM1200A gravity field is 
 LEMOINEETAL2014, published in the Geophysical Research Letters with the 
 DOI number 10.1002/2014GL060027 . For additional details on the GRAIL 
 mission, data and methods, see LEMOINEETAL2013.

 This file is a pair of ASCII tables: a header table and a table of
 1442397 coefficients.  Definitions of the tables follow.</comment>
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      <offset unit="byte">0</offset>
      <records>1</records>
      <description>The SHADR header includes
descriptive information about the spherical harmonic
coefficients which follow in SHADR_COEFFICIENTS_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>
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        <fields>9</fields>
        <groups>0</groups>
        <record_length unit="byte">244</record_length>
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          <name>Reference_Raduis</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>
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          <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 kilometers cubed per seconds 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 kilometers cubed per seconds squared for the
            planet. For a topography model, set to 1.</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>The degree of 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>The 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>
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          <name>Reference_Latitude</name>
          <field_number>8</field_number>
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          <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>
        <Field_Character>
          <name>Fill</name>
          <field_number>9</field_number>
          <field_location unit="byte">138</field_location>
          <data_type>ASCII_String</data_type>
          <field_length unit="byte">105</field_length>
        </Field_Character>
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      <name>SHADR Coefficients Table</name>
      <offset unit="byte">244</offset>
      <records>721800</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>
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          <field_location unit="byte">1</field_location>
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          <field_length unit="byte">5</field_length>
          <description>The 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>
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          <description>The order index n of the C and S coefficients 
            in this record.</description>
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          <description>The coefficient Cmn for this spherical harmonic 
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          <description>The coefficient Smn for this spherical harmonic 
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          <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>The uncertainty in the
            coefficient Cmn for this Spherical Harmonic Model.</description>
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          <description>The uncertainty in the
            coefficient Smn for this Spherical Harmonic Model.</description>
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          <field_location unit="byte">108</field_location>
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