PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2002-03-12 INTERCHANGE_FORMAT = ASCII NOTE = "Description of the DATA directory contents." END_OBJECT = TEXT END DATA Directory Contents ======== Overview ======== The Magnetometer (MAG) vector magnetic field data reside in the subdirectories of the directory DATA/MAG. These data were acquired by the Magnetometer instrument aboard the Near Earth Asteroid Rendezvous (NEAR) spacecraft. The MAG data on this disk cover the period 1998-12-23 to 1998-12-23. The data files belonging to the mission phase of the disk are collected into subdirectories according to the dates of the data that they contain. For example, the directory 1998_350 would contain data collected in 1998 on days 350 - 359. The data files themselves have the file extension TAB. Each data file is an ASCII table containing time tags, magnetic field component and magnitude values, and spacecraft position values. Data are provided in two coordinate systems: Eros Body Fixed (EBF) and NEAR Sun Orbital (NSO) coordinates. Files with names beginning with EBF contain data in EBF coordinates, while files with names beginning with NSO contain data expressed in NSO coordinates. These coordinate systems are described in the text of the PDS label files (*.LBL) associated with the data files (*.TAB). The data are calibrated and processed, and are provided in physical units (nT). In addition, instrumental and spacecraft effects have been removed from the data during processing. The data are described in detail in the files CATALOG/MAGL2DS.CAT and AAREADME.TXT on this disk. Each file consists of an ASCII table containing data for one day. The table in each file has fixed-length records of length 124 bytes. Each row of data contains 13 columns, and is terminated by the ASCII record delimiter characters carriage return and line feed. The columns in the data files are described in the PDS label files associated with the data. This disk also contains browse plots which summarize the MAG data. These are housed in the BROWSE directory and are described in the file BROWSE/BROWINFO.TXT. ======================= File Naming Conventions ======================= The file naming convention for the data files is illustrated by the following example. EBF98357.TAB is interpreted as: EBF = coordinate system of the data 98 = year 1998 357 = day of year 357 (where Jan. 1 = day of year 001) TAB = table format EBF98357.LBL is the name of the PDS label file which describes the data file EBF98357.TAB. Such label files provide descriptive information in a format which is both human-readable and machine-readable. ========= Documents ========= This disk contains documentation files which describe the datasets on the disk, the instruments from which the data came, and the NEAR spacecraft and mission. These files are found in the CATALOG and DOCUMENT directories, and are described in the files CATALOG/CATINFO.TXT and DOCUMENT/DOCINFO.TXT. ================== Web Browser Access ================== The data, browse plots, and documents on this disk can be accessed by means of a World Wide Web browser. The entry point for navigating the disk by this method is the root-level file AAREADME.HTM. That file contains links to other HTML files under the root-level directories EXTRA and BROWSE. The use of a Web browser is not necessary for use of the data on the disk.