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. ----------------------------------------------------------------------------- COVARIANCE Subdirectory: ----------------------------------------------------------------------------- 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. ----------------------------------------------------------------------------- CLONES Subdirectory: ----------------------------------------------------------------------------- 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. ----------------------------------------------------------------------------- GEOTIFF Subdirectory: ----------------------------------------------------------------------------- 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. ----------------------------------------------------------------------------- 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. ----------------------------------------------------------------------------- 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.