urn:nasa:pds:grail_gravity_derived:data_shbdr:jggrx_0900d_shb_l660
1.0
GRAIL Gravity Binary Spherical Harmonic Model: jggrx_0900d_shb_l660
1.18.0.0
Product_Observational
2022-08-16
1.0
Initial PDS4 version
2012-03-01T16:28:00.000Z
2012-12-14T20:56:00.000Z
Gravity Recovery and Interior Laboratory
Mission
urn:nasa:pds:context:investigation:mission.gravity_recovery_and_interior_laboratory
data_to_investigation
Gravity Recovery and Interior Laboratory A
Host
urn:nasa:pds:context:instrument_host:spacecraft.grail-a
is_instrument_host
Gravity Recovery and Interior Laboratory B
Host
urn:nasa:pds:context:instrument_host:spacecraft.grail-b
is_instrument_host
Lunar Gravity Ranging System A for GRAIL-A
Instrument
urn:nasa:pds:context:instrument:grail-a.lgrs-a
is_instrument
Lunar Gravity Ranging System B for GRAIL-B
Instrument
urn:nasa:pds:context:instrument:grail-b.lgrs-b
is_instrument
Moon
Satellite
urn:nasa:pds:context:target:satellite.earth.moon
data_to_target
jggrx_0900d_shb_l660.dat
2013-11-06T00:00:00.000
This file contains coefficients and related data for the JPL Lunar gravity
field GL0900D, a 900th degree and order spherical harmonic model. It is a
JPL gravity field that includes the entire Primary Mission
(March 1, 16:30 to May 29, 16:36, 2012) and the entire Extended Mission of
GRAIL tracking data (August 30, 16:20 to Dec. 14, 20:56, 2012). This
solution uses the version 3 level-1 data for both the primary mission and
extended mission.
Some details describing this model are:
The spherical harmonic coefficients are fully normalized.
The reference radius = 1738.0 km
The planetary ephemeris is de430 and defines the lunar body-fixed
coordinate system.
A power law constraint (1/n^1/2) is applied starting at n=701.
The weighting of the KBRR data is 0.03 to 0.06 microns/sec for the
primary mission and 0.05 microns/sec for the extended mission except
the data from Nov. 19 to Dec. 14 is weighted near 0.2 microns/sec.
The second degree Love number solution is fixed to k2=0.0239.
The second degree gravity coefficients of this model do not include
the permanent tide.
This product contains the truncated n=660 covariance of the GL0900D
gravity model or JGGRX_0900D_SHA.
The reference for the GL0900D gravity field is KONOPLIVETAL2014,
published in Geophysical Research Letters with the DOI number
10.1002/2013GL059066.
This product is a set of binary tables:
a header table, a names table, a coefficients table, and a covariance
table. Definitions of the tables follow. This GRAIL moon gravity model
is in the form of a Spherical Harmonics Binary Data Record (SHBDR).
SHBDR_Header_Table
0
1
The SHBDR Header includes descriptive information about the spherical
harmonic coefficients that follow in SHBDR_Coefficients_Table. The header consists
of a single record of nine data columns requiring 56 bytes. The Header is followed by
a pad of binary integer zeroes.
9
0
56
Reference_Radius
1
1
IEEE754LSBDouble
8
km
The assumed reference radius of the spherical planet.
Constant
2
9
IEEE754LSBDouble
8
For a gravity field model
the gravitational constant GM in km cubed per second
squared for the planet. For a topography model, set to 1.
Uncertainty_in_Constant
3
17
IEEE754LSBDouble
8
For a gravity field model the uncertainty in the
gravitational constant GM in km cubed per second squared for
the planet. For a topography model, set to 0.
Degree_of_Field
4
25
SignedLSB4
4
Degree of the model field.
Order_of_Field
5
29
SignedLSB4
4
Order of the model field.
Normalization_State
6
33
SignedLSB4
4
The normalization indicator. For gravity field:
0 coefficients are unnormalized
1 coefficients are normalized
2 other.
Number_of_Names
7
37
SignedLSB4
4
Number of valid names in
the SHBDR_Names_Table. Also, the number of valid
coefficients in the SHBDR_Coefficients_Table.
Reference_Longitude
8
41
IEEE754LSBDouble
8
degree
Reference longitude for the spherical harmonic
expansion; normally 0.
Reference_Latitude
9
49
IEEE754LSBDouble
8
degree
Reference latitude for the spherical harmonic
expansion; normally 0.
SHBDR_Names_Table
512
436918
The SHBDR_Names_Table contains names for the solution parameters (including
gravity field coefficients) which will follow in SHBDR_Coefficients_Table.
The order of the names in SHBDR_Names_Table corresponds identically to the
order of the parameters in SHBDR_Coefficients_Table. Each coefficient name
is of the form Cij or Sij where i is the degree of the coefficient and j is
the order of the coefficient. Both indices are three-digit zero-filled
right-justified ASCII character strings (for example, C010005 for the 10th
degree 5th order C coefficient, or S002001 for the 2nd degree 1st order
S coefficient). The eighth byte in the table is an ASCII blank used to ensure
that the row length is equal to 8 bytes. Names of other solution parameters are
limited to 8 ASCII characters; if less than 8, they will be left-justified and
padded with ASCII blanks. The Names Table itself will be padded with ASCII blanks,
if necessary.
1
0
8
Parameter_Name
1
1
ASCII_String
8
The name of the coefficient or other solution parameter,
left-justified and padded with ASCII blanks (if needed) to 8
characters.
SHBDR_Coefficients_Table
3495936
436918
The SHBDR_Coefficients_Table contains the coefficients and other
solution parameters for the spherical harmonic model. The order of the
coefficients in this table corresponds exactly to the order of the coefficient
and parameter names in SHBDR_Names_Table. The SHBDR_Coefficients_Table will be
padded with double precision zeroes.
1
0
8
Coefficient_Value
1
1
IEEE754LSBDouble
8
A coefficient Cij or Sij or other solution parameter as specified
in the SHBDR_Names_Table.
SHBDR_Covariance_Table
6991360
95448887821
The SHBDR_Covariance_Table
contains the covariances for the spherical harmonic model
coefficients and other solution parameters. The order of
the covariances in this table is defined as columnwise
vector storage of the upper triangular matrix formed by
the product of the SHBDR Names Table with its transpose.
For example, if the Names Table has four entries A, B,
C, and D, then the covariances are given by the column
vectors in the upper triangular matrix of:
| A | [ A B C D ] = | AA AB AC AD |
| B | | BA BB BC BD |
| C | | CA CB CC CD |
| D | | DA DB DC DD |
That is, the covariance table will list (in this order)
AA, AB, BB, AC, BC, CC, AD, BD, CD, and DD.
The SHBDR_Covariance_Table will be padded with double
precision zeroes
1
0
8
Covariance_Value
1
1
IEEE754LSBDouble
8
The covariance value for the coefficients and other
solution parameters specified by the product of SHBDR_Names_Table
with its transpose, after omitting redundant terms.
jggrx_0900d_shb_l660.lbl
0
PDS3
Original PDS3 label
Carriage-Return Line-Feed