PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 44 FILE_RECORDS = 1038 ^SHADR_HEADER_TABLE = ("NLRG016V.SHA",1) ^SHADR_COVARIANCE_TABLE = ("NLRG016V.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 COVARIANCE" PRODUCT_ID = "NLRG016V.SHA" PRODUCT_RELEASE_DATE = 2001-08-31 DESCRIPTION = " This file contains covariances for the coefficients of the spherical harmonic model of the gravity potential of Eros archived in this same data set with the PRODUCT_ID 'NLRG016A.SHA'. The field is complete to degree and order 16, but covariances are given to degree and order 6. Input data were from the NEAR Laser Rangefinder (NLR) on the NEAR-Shoemaker (NEAR) spacecraft, together with two-way Doppler and range data from radio tracking. The coordinate system is given by the project-supplied orientation SPICE files, with longitudes measured positive east. When evaluated, the model gives the gravitational potential of Eros. 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 the spacecraft using force models and estimates the potential field of celestial bodies and other parameters. This product is an ASCII table containing one row for each pair of coefficient entries. The table represents a full covariance matrix, with 45 rows by 45 columns. Each row or column represents one of the coefficients of NLRG016A.SHA, starting with the C(2,0) coefficient and ending with S(6,6). A covariance matrix is symmetric, so only the upper triangle is given. The gravity model was produced under the direction of D.E. Smith of NASA-Goddard Space Flight Center." NOTE = " The propagation of covariance to incertainties is a complex task which had not yet been performed as of the date these data were archived. When and if the formal uncertainties are calculated and submitted to the PDS, they will be incorporated into the archive." 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" PRODUCER_ID = "NLR SCIENCE TEAM" SOFTWARE_NAME = "GEODYN/SOLVE" OBJECT = SHADR_HEADER_TABLE ROWS = 1 COLUMNS = 5 ROW_BYTES = 44 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The SHADR header includes descriptive information about the spherical harmonic model. The header consists of a single record of five data columns requiring 42 bytes, an ASCII carriage-return, and an ASCII line-feed." OBJECT = COLUMN COLUMN_NUMBER = 1 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 COLUMN_NUMBER = 2 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 COLUMN_NUMBER = 3 NAME = "REFERENCE RADIUS" DATA_TYPE = ASCII_REAL START_BYTE = 11 BYTES = 10 FORMAT = "E10.2" UNIT = "METER" DESCRIPTION = "A normalization value for the equatorial radius" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = "CONSTANT" DATA_TYPE = ASCII_REAL START_BYTE = 21 BYTES = 20 FORMAT = "E20.11" 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 COLUMN_NUMBER = 5 NAME = "NORMALIZATION STATE" DATA_TYPE = ASCII_INTEGER START_BYTE = 41 BYTES = 2 FORMAT = "I2" DESCRIPTION = "The normalization indicator. For gravity field: 0 coefficients are unnormalized 1 coefficients are normalized 2 other." END_OBJECT = COLUMN END_OBJECT = SHADR_HEADER_TABLE OBJECT = SHADR_COVARIANCE_TABLE ROWS = 1035 COLUMNS = 7 ROW_BYTES = 44 INTERCHANGE_FORMAT = ASCII DESCRIPTION = "The SHADR covariance table contains the coefficient covariance for the spherical harmonic model. For each degree index m, order index n, and coefficient Cmn or Smn, the formal covariance of (C,S)mn with any other coefficient is given. The space-delimited data require 42 ASCII characters; these are followed an ASCII carriage-return, and an ASCII line-feed." OBJECT = COLUMN COLUMN_NUMBER = 1 NAME = "COEFFICIENT TYPE 1" DATA_TYPE = CHARACTER START_BYTE = 1 BYTES = 1 FORMAT = "A1" DESCRIPTION = "The coefficient type (C or S) of the first coefficient entry in this record" END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 2 NAME = "COEFFICIENT DEGREE 1" DATA_TYPE = ASCII_INTEGER START_BYTE = 2 BYTES = 4 FORMAT = "I4" DESCRIPTION = "The degree index m of the first C or S coefficient in this record." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 3 NAME = "COEFFICIENT ORDER 1" DATA_TYPE = ASCII_INTEGER START_BYTE = 6 BYTES = 3 FORMAT = "I3" DESCRIPTION = "The order index n of the first C or S coefficient in this record." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 4 NAME = "COEFFICIENT TYPE 2" DATA_TYPE = CHARACTER START_BYTE = 11 BYTES = 1 FORMAT = "A1" DESCRIPTION = "The coefficient type (C or S) of the second coefficient entry in this record." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 5 NAME = "COEFFICIENT DEGREE 2" DATA_TYPE = ASCII_INTEGER START_BYTE = 12 BYTES = 4 FORMAT = "I4" DESCRIPTION = "The degree index m of the second C or S coefficient entry in this record." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 6 NAME = "COEFFICIENT ORDER 2" DATA_TYPE = ASCII_INTEGER START_BYTE = 16 BYTES = 3 FORMAT = "I3" DESCRIPTION = "The order index n of the second C or S coefficient entry in this record." END_OBJECT = COLUMN OBJECT = COLUMN COLUMN_NUMBER = 7 NAME = "C" DATA_TYPE = ASCII_REAL START_BYTE = 19 BYTES = 24 FORMAT = "E24.15" DESCRIPTION = "The covariance (C,S)m1n1(C,S)m2n2 of the spherical harmonic model." END_OBJECT = COLUMN END_OBJECT = SHADR_COVARIANCE_TABLE END