PDS_VERSION_ID = PDS3
RECORD_TYPE = STREAM
OBJECT = TEXT
PUBLICATION_DATE = 1999-12-08
NOTE = "AAREADME.TXT describes this archive product."
END_OBJECT = TEXT
END
Volume MGSM_1001
Mars Global Surveyor
Magnetometer / Electron Reflectometer
MAG/ER Data Archive
Science Phasing Orbits - 1 (SPO1)
Planetary Plasma Interactions Discipline Node
of the
Planetary Data System
==============================================================================
Introduction
==============================================================================
This disk contains the Science Phasing Orbits - 1 (SPO-1) data from the
Mars Global Surveyor (MGS) Magnetometer and Electron Reflectometer (MAG/ER)
instruments, submitted to the Planetary Data System (PDS).
This data product is currently under construction and has not completed
the PDS Peer Review process. Users are encouraged to provide comments back
to the PPI Node of the PDS if errors or omission are found in either the
data or documentation. Please send comments by e-mail or U.S. mail to
Steven Joy sjoy@igpp.ucla.edu
405 Hilgard Ave
UCLA - IGPP
Los Angeles, CA 90095-1567
Questions regarding data content, processing, or quality should be sent to
Dr. J.E.P. Connerney jec@lepjec.gsfc.nasa.gov
NASA Goddard Space Flight Center
Code 695
Greenbelt, MD 20771
------------------------------------------------------------------------------
CAUTION! CAUTION! CAUTION! CAUTION! CAUTION! CAUTION!
THESE MAGNETIC FIELD DATA ARE PRELIMINARY DATA ONLY. THE MGS SPACECRAFT
PRODUCES A SIGNIFICANT MAGNETIC FIELD AT THE SENSOR LOCATIONS.
THE SENSORS ARE LOCATED AT THE OUTER ENDS OF THE SOLAR PANELS. THE
SOLAR PANELS ARE ARTICULATED IN THE SPACECRAFT REFERENCE FRAME DURING
MOST OF THE MISSION. THE SPACECRAFT FIELD IS A FUNCTION OF SENSOR
POSITION RELATIVE TO SPACECRAFT REFERENCE FRAME, HIGH GAIN ANTENNA
(HGA) POSITION AND ATTITUDE, SOLAR PANEL INSOLATION, AND STATE OF THE
POWER SUBSYSTEM.
DURING THIS PHASE OF THE MISSION, THE SOLAR PANELS AND HGA REMAINED
FIXED IN THE FRAME OF REFERENCE OF THE SPACECRAFT. THE SPACECRAFT FIELD
HAS BEEN APPROXIMATED BY A CONSTANT FOR THIS PHASE OF THE MISSION
AND SUBTRACTED FROM THE OBSERVATIONS BY ADJUSTMENT OF THE SENSOR
ZERO TABLES (ESTIMATED ERROR OF A FEW NT).
THE MGS MAGNETOMETER INVESTIGATION HAS NOT AS OF THIS DATE OBTAINED
CALIBRATION MANEUVERS REQUESTED BY MAG AND DEEMED NECESSARY FOR
THE UNAMBIGUOUS CALCULATION OF SPACECRAFT-GENERATED MAGNETIC FIELDS.
CAUTION! CAUTION! CAUTION! CAUTION! CAUTION! CAUTION!
------------------------------------------------------------------------------
==============================================================================
Brief Disk Description
==============================================================================
This volume contains MGS MAG/ER data from the SPO-1 subphase of the orbit
insertion mission phase (1998-03-27 to 1998-04-28). Processed data in
physical units from the Magnetometer are provided at full word downlink
sampling resolution, while those from the Electron Reflectometer are
provided at full downlink sampling resolution.
All data files are stored in the "DATA" branch of the directory tree. Each
instrument is given a subdirectory, and each data set is located in that
subdirectory or in a subdirectory beneath it. All data are stored in ASCII
tables with attached MAG/ER team headers. Time values are expressed in
Spacecraft Event Time (SCET).
The documentation for this volume is located in the CATALOG directory.
Each data set is documented as part of the archive (*DS.CAT); so are
the MAG and ER instruments (*INST.CAT), the MGS mission (MISSION.CAT)
and spacecraft (MGS_HOST.CAT), the MAG/ER team, and useful literature
references.
All data files on this CD-ROM are described by detached PDS labels (.LBL)
and format files (.FMT). 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.
==============================================================================
Volume Set Information
==============================================================================
This CD-ROM is the first volume of the MGSM_1xxx series. This volume set
contains MAG/ER data from the orbit insertion (OI) and mapping phases. The
volume series will have at least 1 CD-ROM per OI subphase, followed by
1 volume for every 2-3 months during the mapping phase.
==============================================================================
Volume Format Information
==============================================================================
The disk is organized into a hierarchical directory structure. The disk
is formatted according to both ISO 9660 and POSIX (UNIX) standards in order
to accommodate users on a wide variety of platforms. This volume does not
contain any Extended Attribute Records (XAR). Thus, VAX/VMS users may have
some problems accessing files on this volume.
==============================================================================
File Formats
==============================================================================
The data files on this volume are ASCII text files. 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 98097.STS is accompanied by the detached
label file 98097.LBL in the same directory. File names within this
archive comply with the "8.3" convention to conform with the ISO-9660
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, *.STS) 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, PDS label, and ASCII table 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 the HTML 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., SERIES, 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:
^SERIES = ("20903684.DAT", 3)
indicates that the SERIES object begins at record 3 of the file
20903684.DAT, 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 the beginning of the file (record 1,
byte 1); default is record number.
<BYTES> indicates that number given is in units of bytes.
filename upper-case file name.
ext upper-case file extension.
dirlist* period-delimited path-list of parent directories,
in upper case, that specifies the object 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"
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.
==============================================================================
Errata
==============================================================================
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 MGSM_1xxx CD-ROM after the
production of this volume can be found on the PPI Node errata Web page
(http://www.igpp.ucla.edu/ssc/pdsppi/Welcome.html). Also, they can be
obtained via anonymous ftp at pdsppi.igpp.ucla.edu. The account name is
"anonymous" and the password should be your e-mail address (it's polite
to leave an audit trail). Locate yourself in the PDS errata directory
(cd pds/ERRATA/MGSM_1xxx), and transfer the file ERRATA.TXT
(get 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 support and feedback of the users of these data can an
effective errata list be maintained.
==============================================================================
Software
==============================================================================
There is no software provided with these data at this time.
==============================================================================
Volume Contents and Structure
==============================================================================
This section describes the volume structure and naming conventions. Below is
a tree diagram of the CD-ROM, followed by a description of the directory
function and key files in each directory.
MGSM_1xxx (root directory)
|
|- AAREADME.TXT Describes volume contents, organization and CD-ROM use
| (this file).
|
|- AAREADME.HTM An HTML version of AAREADME.TXT. Can be viewed
| in a Web browser and used to navigate the data.
|
|- ERRATA.TXT Describes known deficiencies or caveats in the data or
| on this CD-ROM.
|
|- VOLDESC.CAT High-level description of CD-ROM contents.
|
|- [BROWSE] PostScript files containing plots of trajectory and
| | magnetic field data.
| |
| |-[RMS] 3-panel plots showing magnitude of B field along
| | with RMS values of components BX and BY.
| |
| |-[XYPLANE] Plots of XY-plane projections of spacecraft
| | trajectory and magnetic field vectors.
| |
| |-[XZPLANE] Plots of YZ-plane projections of spacecraft
| | trajectory and magnetic field vectors.
| |
| |-[YZPLANE] Plots of XZ-plane projections of spacecraft
| | trajectory and magnetic field vectors.
|
|- [CATALOG] Information on data sets and how they are processed
| and produced. Also contains information regarding
| Mars Global Surveyor, the instruments covered by this
| volume, personnel involved, and references from
| various documents including those contained in the
| CATALOG directory.
|
|- [DATA] Contains all data in a branching tree structure of
| | subdirectories.
| |
| |- [ANCIL] Ancillary data pertaining to the spacecraft and
| | its trajectory, in the form of kernel files.
| |
| |- [ER] Data sets from the Electron Reflectometer (ER).
| |
| |- [MAG] Data sets from the Magnetometer (MAG).
| |
| |- [PCENTRIC] MAG data expressed in a planetocentric (PC)
| | coordinate system.
| |
| |- [SUNSTATE] MAG data expressed in a Sun-State (SS)
| | coordinate system.
|
|- [DOCUMENT] Contains documents describing the data on the volume.
|
|- [EXTRAS] Contains files which facilitate use of the disk, but
| which are not required for such use. These files
| include HTML pages with links to data on the disk.
|
|- [GEOMETRY] Contains a table of spacecraft trajectory data,
| comprised of data describing individual orbits, and
| kernel files.
|
|- [INDEX] Contains a table of contents for all files located on
| the CD-ROM and the volume set to date.
|
|- [MANAGE] For PDS use only; no user files.
==============================================================================
Driver and Hardware Information
==============================================================================
This disk has been formatted according to the ISO standard for CD-ROM
production (9660) with level 1 compliance. Any system which complies with
this standard (all of them should) should be able to access this disk.
==============================================================================
Contacts
==============================================================================
The person most directly responsible for the construction and release of this
CD-ROM is Mr. Steven Joy. He was the PPI Node Data Administrator at the time
this disk was created and understands as much about the disk structure and
data organization as anyone. Other PPI personnel who may be aware of issues
related to this CD-ROM include Dr. Mark Sharlow and Dr. Raymond Walker,
the PDS/PPI Node manager.
For questions or problems regarding this CD-ROM, please contact the PDS/PPI
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
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.