PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 76 FILE_RECORDS = 152 ^SHADR_HEADER_TABLE = ("NLRG016A.SHA",1) ^SHADR_COEFFICIENTS_TABLE = ("NLRG016A.SHA",2) SPACECRAFT_NAME = "NEAR EARTH ASTEROID RENDEZVOUS" TARGET_NAME = EROS INSTRUMENT_NAME = "NEAR LASER RANGEFINDER" DATA_SET_ID = "NEAR-A-NLR-6-EROS-MAPS-MODELS-V1.0" OBSERVATION_TYPE = "GRAVITY MODEL" PRODUCT_ID = "NLRG016A.SHA" PRODUCT_RELEASE_DATE = 2001-08-31 DESCRIPTION = " This file contains coefficients and related data for a spherical harmonic model of the gravity potential of Eros. The field is complete to degree and order 16. Input data are from the NEAR Laser Rangefinder (NLR) on the NEAR-Shoemaker (NEAR) spacecraft, together with two-way Doppler and range data from radio tracking. Coordinate system is given by the project-supplied orientation SPICE files, with longitudes measured positive east. When evaluated, the model gives absolute radius from Eros center of mass in meters. The potential model is the solution NLR393V3, from the orbit determination and parameter estimation program GEODYN/SOLVE. This software integrates the equations of motion of spacecraft using force models, and estimates the potential field of celestial bodies and other parameters. This product is a set of two ASCII tables: a header table and a coefficients table. Definitions of the tables follow. This gravity model was produced under the direction of D.E. Smith of NASA-Goddard Space Flight Center." START_TIME = 2000-03-05T00:00:04 STOP_TIME = 2001-02-12T19:42:43 PRODUCT_CREATION_TIME = 2000-06-06T18:22:00 PRODUCER_FULL_NAME = "MARK TORRENCE" PRODUCER_INSTITUTION_NAME = "GODDARD SPACE FLIGHT CENTER" PRODUCT_VERSION_TYPE = "PRELIMINARY" PRODUCER_ID = "NLR SCIENCE TEAM" SOFTWARE_NAME = "GEODYN/SOLVE" OBJECT = SHADR_HEADER_TABLE ROWS = 1 COLUMNS = 8 ROW_BYTES = 76 INTERCHANGE_FORMAT = ASCII 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 74 bytes, an ASCII carriage-return, and an ASCII line-feed." OBJECT = COLUMN NAME = "DEGREE OF FIELD" DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 5 FORMAT = "I5" DESCRIPTION = "Degree of the model field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "ORDER OF FIELD" DATA_TYPE = ASCII_INTEGER START_BYTE = 6 BYTES = 5 FORMAT = "I5" DESCRIPTION = "Order of the model field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFERENCE RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 11 BYTES = 19 FORMAT = "E19.11" UNIT = "METER" DESCRIPTION = "A normalization value for the equatorial radius." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "CONSTANT" DATA_TYPE = ASCII_REAL START_BYTE = 30 BYTES = 19 FORMAT = "E19.11" UNIT = "METERS CUBED PER SECONDS SQUARED" DESCRIPTION = "For a gravity field model the assumed gravitational constant GM in meters cubed per seconds squared for the planet. For a topography model, set to 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "UNCERTAINTY IN CONSTANT" DATA_TYPE = ASCII_REAL START_BYTE = 49 BYTES = 13 FORMAT = "E13.5" UNIT = "METERS CUBED PER SECONDS SQUARED" DESCRIPTION = "For a gravity field model the uncertainty in the gravitational constant GM in meters cubed per seconds squared for the planet (or, set to 0 if not known). For a topography model, set to 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "NORMALIZATION STATE" DATA_TYPE = ASCII_INTEGER START_BYTE = 62 BYTES = 3 FORMAT = "I3" DESCRIPTION = "The normalization indicator. For gravity field: 0 coefficients are unnormalized 1 coefficients are normalized 2 other." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFERENCE LONGITUDE" POSITIVE_LONGITUDE_DIRECTION = "EAST" DATA_TYPE = ASCII_REAL START_BYTE = 65 BYTES = 5 FORMAT = "F5.1" UNIT = "DEGREE" DESCRIPTION = "The reference longitude for the spherical harmonic expansion; normally 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "REFERENCE LATITUDE" DATA_TYPE = ASCII_REAL START_BYTE = 70 BYTES = 5 FORMAT = "F5.1" UNIT = "DEGREE" DESCRIPTION = "The reference latitude for the spherical harmonic expansion; normally 0." END_OBJECT = COLUMN END_OBJECT = SHADR_HEADER_TABLE OBJECT = SHADR_COEFFICIENTS_TABLE ROWS = 151 COLUMNS = 6 ROW_BYTES = 76 INTERCHANGE_FORMAT = ASCII 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 74 ASCII characters; these are followed an ASCII carriage-return, and an ASCII line-feed." OBJECT = COLUMN NAME = "COEFFICIENT DEGREE" DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 5 FORMAT = "I5" DESCRIPTION = "The degree index m of the C and S coefficients in this record." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "COEFFICIENT ORDER" DATA_TYPE = ASCII_INTEGER START_BYTE = 6 BYTES = 5 FORMAT = "I5" DESCRIPTION = "The order index n of the C and S coefficients in this record." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "C" DATA_TYPE = ASCII_REAL START_BYTE = 11 BYTES = 19 FORMAT = "E19.11" DESCRIPTION = "The coefficient Cmn for this spherical harmonic model." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "S" DATA_TYPE = ASCII_REAL START_BYTE = 30 BYTES = 19 FORMAT = "E19.11" DESCRIPTION = "The coefficient Smn for this spherical harmonic model." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "C UNCERTAINTY" DATA_TYPE = ASCII_REAL START_BYTE = 49 BYTES = 13 FORMAT = "E13.5" DESCRIPTION = "The uncertainty in the coefficient Cmn for this spherical harmonic model. When not provided, set to 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = "S UNCERTAINTY" DATA_TYPE = ASCII_REAL START_BYTE = 62 BYTES = 13 FORMAT = "E13.5" DESCRIPTION = "The uncertainty in the coefficient Smn for this spherical harmonic model. When not provided, set to 0." END_OBJECT = COLUMN END_OBJECT = SHADR_COEFFICIENTS_TABLE END