PDS_VERSION_ID = PDS3
RECORD_TYPE = STREAM
OBJECT = TEXT
INTERCHANGE_FORMAT = ASCII
PUBLICATION_DATE = 2021-03-23
NOTE = "Description of contents of the EXTRAS directory"
END_OBJECT = TEXT
END
This directory contains 3 subdirectories, COVARIANCE, CLONES, and GEOTIFF.
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COVARIANCE Subdirectory:
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This directory contains the following files as a reference to allow the user
to confirm proper reading of the (binary) SHBDR files:
GGGRX_0660PM_SHB_L05_COEFFICIENTS.ASC:
Parameter description (name, value, sigma) for SHBDR file
GGGRX_0660PM_SHB_L50.DAT. GGGRX_0660PM_SHB_L05_COEFFICIENTS.TXT is the
associated label file.
GGGRX_0660PM_SHB_L05_COVARIANCE.ASC:
This file gives the (symmetric) covariance matrix, truncated at L=5, in
ASCII format, from GGGRX_0660PM_SHB_L50.DAT. There are 37
lines/rows/parameters, and the format is "%20.13e " repeated 37 times. Line
feed and carriage return characters complete the line (DOS format).
GGGRX_0660PM_SHB_L05_COVARIANCE.TXT is the associated label file.
JGGRX_0660B_SHB_L05_COEFFICIENTS.ASC:
Parameter description (name, value, sigma) for SHBDR file
JGGRX_0660B_SHB_L50.DAT. JGGRX_0660B_SHB_L05_COEFFICIENTS.TXT is the
associated label file.
JGGRX_0660B_SHB_L05_COVARIANCE.ASC:
This file gives the (symmetric) covariance matrix, truncated at L=5, in
ASCII format, from JGGRX_0660B_SHB_L50.DAT. There are 33
lines/rows/parameters, and the format is "%20.13e " repeated 33 times. Line
feed and carriage return characters complete the line (DOS format).
JGGRX_0660B_SHB_L05_COVARIANCE.TXT is the associated label file.
GGGRX_0900C_SHB_L05_COEFFICIENTS.ASC:
Parameter description (name, value, sigma) for SHBDR file
GGGRX_0900C_SHB_L50.DAT. GGGRX_0900C_SHB_L05_COEFFICIENTS.TXT is the
associated label file.
GGGRX_0900C_SHB_L05_COVARIANCE.ASC:
This file gives the (symmetric) covariance matrix, truncated at L=5, in
ASCII format, from GGGRX_0900C_SHB_L50.DAT. There are 34
lines/rows/parameters, and the format is " %25.16e" repeated 34 times. Line
feed and carriage return characters complete the line (DOS format).
GGGRX_0900C_SHB_L05_COVARIANCE.TXT is the associated label file.
GGGRX_0900C_SHB_L50_COEFFICIENTS.ASC:
Parameter description (name, value, sigma) for SHBDR file
GGGRX_0900C_SHB_L50.DAT. GGGRX_0900C_SHB_L50_COEFFICIENTS.TXT is the
associated label file.
GGGRX_0900C_SHB_L50_COVARIANCE.ASC:
This file gives the (symmetric) covariance matrix, truncated at L=50, in
ASCII format, from GGGRX_0900C_SHB_L50.DAT. There are 2599
lines/rows/parameters, and the format is " %25.16e" repeated 2599 times.
Line feed and carriage return characters complete the line (DOS format).
GGGRX_0900C_SHB_L50_COVARIANCE.TXT is the associated label file.
JGGRX_0900D_SHB_L05_COEFFICIENTS.ASC:
Parameter description (name, value, sigma) for SHBDR file
JGGRX_0900D_SHB_L50.DAT. JGGRX_0900D_SHB_L05_COEFFICIENTS.TXT is the
associated label file.
JGGRX_0900D_SHB_L05_COVARIANCE.ASC:
This file gives the (symmetric) covariance matrix, truncated at L=5, in
ASCII format, from JGGRX_0900D_SHB_L50.DAT. There are 33
lines/rows/parameters, and the format is " %20.13e" repeated 33 times. Line
feed and carriage return characters complete the line (DOS format).
JGGRX_0900D_SHB_L05_COVARIANCE.TXT is the associated label file.
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CLONES Subdirectory:
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This directory contains 500 "clones" of the GRGM900C field, each uniquely
identified by an index number (0001-0500). The clones are organized into
folders of 100 files each.
Each clone is a member of a statistical ensemble based on the GRGM900C
covariance. Instead of the computationally expensive method of diagonalizing
the full covariance matrix, a Monte Carlo method is used. For more detail on
this method, see CLONE_DESCRIPTION.PDF/LBL in this directory.
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GEOTIFF Subdirectory:
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This directory contains non-PDS-standard products provided to users to
facilitate the use and analysis of GRAIL gravity maps. The GeoTIFF files
contain the same data as the corresponding files in the RSDMAP folder of the
main GRAIL archive. Popular mapping software such as ESRI ArcMap and QGIS are
able to import the GeoTIFF files directly.
Most of the files in this EXTRAS/GEOTIFF folder correspond to the GSFC
GRGM1200A gravity field obtained from GRAIL primary and extended mission
data. The map products are expanded with various degree and order
truncations, which can be useful in various studies.
There are six types of maps:
- Gravity Anomaly maps (GGGRX_1200A_ANOM_L*.TIF)
- Gravity Disturbance maps (GGGRX_1200A_DIST_L*.TIF)
- Gravity Bouguer Disturbance maps (GGGRX_1200A_BOUG_L*.TIF)
- Gravity Anomaly Error maps (GGGRX_1200A_ANOMERR_L*.TIF)
- Geoid Height map (GGGRX_1200A_GEOID_L660.TIF)
- Degree Strength map (GGGRX_1200A_DEGSTR.TIF)
The GeoTIFF subdirectory also contains some files that correspond to the GSFC
GRGM1200L gravity field. See GRGM1200L_DESCRIPTION.TXT for a description of
these files.
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Users are encouraged to refer to the label files (.LBL) of the corresponding
IMG products in the RSDMAP directory of the main GRAIL PDS archive.
The main PDS GRAIL archive's RSDMAP products can be found at the following URL:
http://pds-geosciences.wustl.edu/grail/grail-l-lgrs-5-rdr-v1/grail_1001/rsdmap/
All EXTRAS products are provided at the discretion of the GRAIL Science Team
and are not supported.
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Also included in the EXTRAS directory is the following file:
FORTNIGHT_CALCULATION.XLS: This is a supporting document for
ONCE_UPON_A_FORTNIGHT.PDF, JPL D-61501, containing the numerical content
described therein, as a Microsoft Excel file. This is the original version
of the file FORTNIGHT_CALCULATION.PDF, located in the DOCUMENT directory.