NEAR Shoemaker Magnetometer CD-ROM Series
Volume NMERFB_2001
Planetary Data System
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This disk contains a subset of the EROS/FLY/BY phase calibrated data (Reduced Data Record) from the Near Earth Asteroid Rendezvous (NEAR) Magnetometer instrument, submitted to the Planetary Data System (PDS).
Users are encouraged to provide comments back to the PPI Node of the PDS if errors or omissions are found either in data or in documentation. Please send comments by e-mail or U.S. mail to PDS Operator as defined at the end of this document.
For questions regarding data content, processing, or quality, please see the contact information at the end of this document.
This volume contains NEAR MAG data from the EROS/FLY/BY phase of the mission. This phase began on 1998-12-23 and ended on 1998-12-23. The data are in physical units and are expressed in two different coordinate systems, NEAR Sun Orbital (NSO) and Eros Body Fixed (EBF). The data are further described by the file /CATALOG/MAGL2DS.CAT on this disk.
All data files are stored in the /DATA branch of the directory tree. Each data file is located in the /DATA directory or in a subdirectory beneath it. All data are stored in ASCII table format.
The primary documentation for this volume is located in the CATALOG directory. The data set is documented as part of the archive (MAGL2DS.CAT); so are the instrument (MAGINST.CAT), the NEAR mission (MISSION.CAT), the NEAR spacecraft (INSTHOST.CAT), relevant personnel (PERSON.CAT), and useful literature references (REF.CAT).
All data files on this CD-ROM are described by detached PDS labels (*.LBL). Each detached label file contains information about the corresponding data file, including descriptions of the columns if the data file is tabular. Metadata are stored as text files with the data. Information on the particular form of metadata used in the PDS catalog can be found in the CATALOG directory.
NEAR data sets contain data from only one instrument and one mission phase. Mission phases for data sets are defined in the table below. Each data set contains the data from a range of days, along with supporting documentation for those data. A data set may span one or more volumes.
Mission Phase Parameters (Planned Values; Feb. 2000)
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Segment Start (Year, End (Year, Length
Phase Name (Phase Abbrv) Day Of Year) Day Of Year) (Days)
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CRUISE1 CRU1 1996-051 1997-175 491
MATHILDE MATH 1997-176 1997-178 3
CRUISE2 CRU2 1997-179 1998-022 209
EARTH ERTH 1998-023 1998-026 4
CRUISE3 CRU3 1998-027 1998-356 330
EROS/FLY/BY ERFB 1998-357 1998-357 1
CRUISE4 CRU4 1998-358 2000-010 383
EROS/ORBIT EROS 2000-011 2001-043 399
EROS/SURFACE ERSF 2001-044 2001-059 16
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The NEAR Science Data Center (SDC) archives NEAR uncalibrated science data at the Small Bodies Node (SBN) of the Planetary Data System (PDS), as specified in the NEAR Project Archive Generation, Validation and Transfer Plan (February 1998).
The data set on this disk is a part of the NEAR level 2 data set delivery as described by the NEAR PDS Data Archive Plan. The Plan also describes the higher level data products, which will become separate PDS data sets.
The February 1998 Plan document is in the DOCUMENT subdirectory of this data set, in the file PDSARCHIVEPLAN, in text (.TXT) and rich text (.RTF) formats. The included plan is dated February 1998. It is expected to be updated with final definitions of higher level products. The revised plan will be included in later time periods of this data set.
The disk is organized into a hierarchical directory structure. The disk is formatted according to the ISO-9660 Level 2 Interchange Standard. This volume does not contain any Extended Attribute Records (XAR). Thus, VAX/VMS users may have some problems accessing files on this volume.
The data files on this volume are in ASCII table format. All data files are described by detached PDS labels. A detached label file has the same name as the data file that it describes, but with the extension .LBL. For example, the file MAG01050.TAB is accompanied by the detached label file MAG01050.TAB in the same directory. File names within this archive conform with the ISO-9660 Level 2 standard.
All documents, detached PDS labels, and HTML files are stream format files, with a carriage return (ASCII 13) and a line feed character (ASCII 10) at the end of the record. This allows the files to be read by MacOS, DOS, Windows, UNIX, and VMS operating systems. UNIX system users will see an unnecessary carriage return character (^M) at the end of each line. Mac users will see an unnecessary line feed character (^J) at the start of each line.
ASCII tabular data files (*.TAB), including data and index files, are formatted so that they may be read directly into many database management systems (DBMS) or spreadsheet programs on various computers. All fields are of fixed length and are separated by white space (blank characters or commas). Character fields are left justified, and numeric fields are right justified. The "start byte" and "bytes" values listed in a PDS label do not include the white space between fields. The records are of fixed length, and the last two bytes of each record contain the ASCII carriage return and line feed characters. This allows a table to be treated as a fixed length record file on computers that support this file type and as a normal text file on other computers.
The document and PDS label files on this volume can be viewed with a Web browser. Note that to view these files, the browser may need to be configured to recognize files with extensions of .LBL and .TAB as text files. Users with Web browsers also can navigate the disk via this file, AAREADME.HTM, in the disk's root directory and the HTML files in the EXTRAS directory.
PDS labels are object-oriented. The object to which the label refers (e.g., TABLE, etc.) is denoted by a statement of the form:
^object = location
in which the caret character (^, also called a pointer in this context) indicates that the object starts at the given location. For an object in the same file as the label, the location is an integer representing the starting record number or byte of the object (the first record/byte in the file is 1). For an object located outside the label file, the location denotes the name of the file containing the object, along with the starting record or byte number. For example:
^TABLE = ("MAG01050.TAB", 3)
indicates that the TABLE object begins at record 3 of the file MAG01050.TAB, in the same directory as the detached label file. Below is a list of the possible formats that use the ^object keyword.
^object = n
^object = n<BYTES>
^object = ("filename.ext",n)
^object = ("[dirlist]filename.ext",n)
^object = ("filename.ext",n<BYTES>)
^object = ("[dirlist]filename.ext",n<BYTES>)
where n is the starting record or byte number of the object, counting from beginning of the file (re cord 1, byte 1); default is record number.
<BYTES> indicates that number given is in units of bytes.
filename is upper-case file name.
ext is upper-case file extension.
dirlist is a period-delimited path-list of parent directories, in upper case, that specifies the obj ect file directory (used only when the object is not in the same directory as the label file).*
* All PDS labels on this volume are located in the same directory as the file they describe, so this construct is not used here.
In cases where many files of the same format or structure are present, the structure description component is detached from the primary label. This minimizes repeating information which does not vary from file to file. In these cases, a format file (.FMT) contains the file structure information and the base label (.LBL) describes the parameters which generally do vary from file to file (number of records, file name, start/stop time, etc.). When a format file is used within the PDS label, the syntax is:
^STRUCTURE = filename
Example:
^STRUCTURE = ''EDRHDR.FMT''
(where the '' represents one double-quotation mark). Syntactically, the contents of the format file can be inserted directly into the base label such that the entire file contents replace the single line ^STRUCTURE = filename.
There is a file called ERRATA.TXT found at the root level of this volume which contains a list of known deficiencies or caveats associated with data on this volume at the time this CD was published. Any changes or errors that are found on this or any NEAR MAG EDR CD-ROM after the production of this volume can be found on a PPI Node errata Web page (http://www.igpp.ucla.edu/public/pds/ERRATA/NEAR/EDR/ERRATA.TXT).
If you find an error on this disk, please report the error to the PDS Operator at the PPI Node of the PDS.
Internet: pds_operator@igpp.ucla.edu
Telephone: (310) 206-6073
U.S. Mail:
PDS Operator
c/o Dr. Raymond Walker
UCLA - IGPP
Los Angeles, CA 90095-1567
Only through the support and feedback of the users of these data can an effective errata list be maintained.
This disk includes a version of the Splash software, which allows the user of the disk to make plots of the data. The Splash program is in the directory EXTRAS/SPLASH. The subdirectories of EXTRAS/SPLASH contain files which, when opened with Splash, allow the user to plot much of the data on the disk.
The Splash software runs only on Windows PC platforms, and must be installed on the user's hard drive before it will run.
The Splash software was developed at the Institute of Geophysics and Planetary Physics at the University of California, Los Angeles. The software is protected by copyright; please refer to the notices in the software. Users are responsible for respecting all copyrights.
This section describes the volume structure and naming conventions.
Below is a tree diagrams for the CD-ROM, followed by descriptions of the directory functions and of key files in each directory.
See the *INFO.TXT file in each directory for specific information on the files in that directory.
Directory structure of the first volume for a dataset:
|-AAREADME.TXT The text version of the AAREADME file.
|-ERRATA.TXT Text information describing data errors/anomalies.
|-VOLDESC.CAT Description of the contents of this volume.
|-BROWSE---
|-CATALOG--
|-DATA-----
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|-DOCUMENT-|-MAG_SW-
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|-EXTRAS-|-SPLASH-
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|-GEOMETRY-
|-INDEX----
Directory Name Description
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CATALOG Templates for the mission, instrument host, instrument,
and data set.
BROWSE The BROWSE directory has a structure identical to the data
directories on this CD, where each contains plots of NEAR MAG
data in NEAR Sun Orbital (NSO) and Eros Body Fixed (EBF)
coordinate systems.
DATA The data are processed scientific data provided in physical
units using the two coordinate systems Near Sun Orbital (NSO)
and Eros Body Fixed (EBF). Magnetic field data are provided
in plot and ASCII table formats, with ASCII data also
providing spacecraft position. In addition to the data
files, documentation is available on the calibration and
data processing techniques. This data set is archived as a
set of CDROM images.
DOCUMENT The DOCUMENT directory contains the magnetometer calibration
document, a mission overview and a subdirectory containing some
magnetometer software used to process the data. The calibration
document is available in ASCII, Microsoft Word and rich text
formats. The mission overview is available in ASCII and Adobe
PDF format. The software subdirectory contains two
documents: the first is a colletion of software used by the
NEAR Science Data Center and the second is a collection of
software used to produce the science data files.
EXTRAS Contains Splash software and part of the HTML interface.
GEOMETRY This directory contains only a GEOMINFO.TXT file.
A separate GEOMETRY volume contains all of the SPICE kernels in
text transfer format for the mission phase and the supporting
the supporting documentation.
INDEX INDEX TABLES for this CD and the volume set describing times and
key data file parameter values.
Driver and Hardware Information
This disk has been formatted according to the ISO standard for CD-ROM production (9660) with level 2 compliance. Any system which complies with this standard should be able to access this disk.
Questions regarding data content, processing, or quality may be directed to:
NEAR Science Data Center:
Kazue Takahashi
The Johns Hopkins University
Applied Physics Laboratory
11100 Johns Hopkins Road
Laurel MD 20723
Email: kazue.takahashi@jhuapl.edu
For questions or problems regarding this CD-ROM, please contact the PPI Node PDS operator:
Internet pds_operator@igpp.ucla.edu
Telephone (310) 206-6073
U.S. Mail:
PDS Operator
c/o Dr. Raymond Walker
3845 Slichter Hall
UCLA - IGPP
Los Angeles, CA 90095-1567
PPI Node personnel who may be aware of issues related to this CD-ROM include Dr. Mark Sharlow, Mr. Steven Joy, and Dr. Raymond Walker.
For questions regarding PDS Standards or other CD-ROM's available from the PDS, please contact PDS Operator at the PDS Central Node (at JPL):
Internet pds_operator@jpl.nasa.gov
Telephone (818) 354-4321
U.S. Mail:
Planetary Data System, PDS Operator
Jet Propulsion Laboratory
Mail Stop 202-101
4800 Oak Grove Dr.
Pasadena, CA 91109-8099
The PDS and the Planetary Plasma Interactions (PPI) Node in particular, assume no legal liability for errors on this disk. All users are encouraged to verify the "correctness" of the data prior to submitting any publications or other work based on these data. Errors on this disk should be reported back to the PPI Node of the PDS through the ERRATA reporting procedures described above.