Lunar Prospector MAG/ER Level 1B DVD Series
Volume 4 (LP_1204)
Planetary Data System
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This disk contains level 1B data from April 1 - July 29, 1999, acquired by the Magnetometer/Electron Reflectometer (MAG/ER) experiment on the Lunar Prospector (LP) spacecraft, and submitted to the Planetary Plasma Interactions Node (PPI) of the Planetary Data System (PDS) for archive. Every effort has been made to ensure that the data and documentation are of the best possible quality. However, mistakes are inevitable. The PPI Node of the PDS will maintain an online list of ERRATA where errors and updates are documented. (See the Errata section of this document for further information.) Should any user of this product find an error on this volume, please report the error to the PPI Node so that the finding can be made public. All users are encouraged to verify the "correctness" of the data prior to submitting any publications or other work based on these data. Users of these data are encouraged to acknowledge both the PDS and the principal investigators of the instruments whose data is used in analysis in all publications.
The data contained on this volume were acquired by the MAG and ER instruments. There are four (4) data sets contained herein. These are a magnetic field vector time series data set, a 16 spin (~80 second) averaged ER time series data set, a spin (~5 second) averaged ER time series data set from 2 selected energy channels, and a data set of 3D electron energy spectra (1/2 spin accumulation, 16 spin sampling) from the ER portion of the instrument.
All data files are stored in the "DATA" branch of the directory tree. Each data set is given a subdirectory and each month of data is located in a subdirectory beneath that. All data are stored in ASCII day files. The file naming convention is ffYYMMDD.TAB where ff is the data type identifier and YYMMDD is the year, month and day of data in the file. All time values are the Universal Time of data acquisition or Spacecraft Event Time (SCET). When data are averaged or binned, the time tag or energy bin stated is the center of the average or bin. When data are binned according to energy, the centers of the energy bins, along with the times at which those center values became applicable, are listed in a file E_BINS.TAB in the data set directory.
All files on this disk are described by detached PDS labels (.LBL) and format files (.FMT). The particular form of metadata used in the PDS catalog can be found in the CATALOG directory.
Any documents which have been provided for inclusion with this volume can be found in the DOCUMENT directory. Each document is located in a subdirectory. A single document may be provided in many forms. At a minimum, there will be an ASCII or HTML version of each document. (Any exceptions to this rule will be noted in the Errata for the volume.) Other formats, such as PDF, Postscript, Microsoft Word, etc., may be included for user convenience. Figures on this disk are provided in GIF87A format.
This disk is the fourth volume of the LP_120x series. This volume set contains MAG/ER data from the Lunar Prospector orbital operations. The volume series will have one volume for approximately every 5 months of data.
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.
The files on this volume include both ASCII and binary files. Data files are described by detached PDS labels, while text files have attached 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 ATTITUDE.TAB is accompanied by the detached label file ATTITUDE.LBL in the same directory. File names within this archive comply with the "8.3" convention to conform with the ISO-9660 standard.
All document files, 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 and Macintosh users will see the unnecessary carriage return character (^M) at the end of each line. Mac users will see an unnecessary line feed (^J) character at the start of each line. ASCII tabular data files (*.TAB) 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. Also, this disk contains HTML files whose links can be used for navigation of the data. Links to these HTML files can be found in the present document, at the top and elsewhere.
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). If this value is omitted, then the data begin at record one (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.
Examples:
^TABLE = "EL980601.DAT"
^TABLE = ("19980601.DAT", 3)
The first example points would tell the user that file EL980601.DAT is described by a TABLE object and the data begin at record 1 of the file. The other TABLE object begins at record 3 of the file 19980601.DAT. In both cases, the data files exist 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 (record 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 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 from the label is detached from the primary label and placed in a separate file. This minimizes repetition of 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 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 = ''ER_DATA.FMT''
(where the '' represents one double-quotation mark). Syntactically, the contents of the format file can be inserted directly into the base label in such a way 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 disk was published. Any changes or errors that are found on this or any LP_120* disk after the production of this volume can be found on the PPI Node LP errata Web page at http://www.igpp.ucla.edu/public/pds/ERRATA/LP/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.
There is no software provided with these data.
This section describes the volume structure and naming conventions for this disk. Below is a tree diagram of the disk, followed by a description of the directory function and key files in each directory.
LP_120x (root directory) | | |- AAREADME.TXT Describes volume contents, organization and disk | use. (The file you are reading now is an HTML | version of this file.) | | |- AAREADME.HTM The file you are reading now. 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 disk. (A Web version of this file, which may | be more up-to-date, can be obtained via this link.) | | |- VOLDESC.CAT High-level description of disk contents. | | |- [BROWSE] This directory contains plots which summarize | | the MAG and ER data, in one-month subdirectories. | | | |-[99_04APR] | |-[99_05MAY] | |-[99_06JUN] | |-[99_07JUL] | | |- [CATALOG] Contains documentation on datasets and how they are | processed and produced. Also contains information | regarding the Lunar Prospector spacecraft, the | instruments covered by this volume, personnel | involved, and references from various documents. | | |- [DATA] Contains all data in a branching tree structure of | | subdirectories. | | | |- [MAG] Magnetometer vector data organized into | | | one-month subdirectories. | | |-[99_04APR] | | |-[99_05MAY] | | |-[99_06JUN] | | |-[99_07JUL] | | | |- [ER_LO_TS] ER low-resolution (~80 sec) time series | | | data for all 15 energy channels, organized | | |-[99_04APR] into one-month subdirectories. | | |-[99_05MAY] | | |-[99_06JUN] | | |-[99_07JUL] | | | |- [ER_HI_TS] ER high-resolution (~5 sec) time series | | | data from two selected energy channels, | | |-[99_04APR] organized into one-month subdirectories. | | |-[99_05MAY] | | |-[99_06JUN] | | |-[99_07JUL] | | | |- [ER_3DIST] ER 3D electron energy spectrum data, | | | organized into one-month subdirectories. | | |-[99_04APR] | | |-[99_05MAY] | | |-[99_06JUN] | | |-[99_07JUL] | | | |- [ANCIL] A table of telemetry outages, useful for | | the interpretation of MAG and ER data. | | |- [DOCUMENT] Contains various documents that facilitate the | | understanding of the datasets included on | | this volume. | | | |- [PROJECT] LP project documentation describing raw | | telemetry data formats, spacecraft commanding, | | ephemeris generation, etc. | | | |- [INST] LP project documentation describing the | | MAG/ER instrument telemetry format. | | | |- [DATADESC] A text file describing the formats of the | | the various MAG/ER datasets. | | | |- [COMMANDS] Contains spacecraft command logs for the time period | | covered by this disk. | | |- [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 spacecraft attitude and ephemeris data as | | ASCII tables. Also includes a SPICE planetary | | ephemeris file (.TSP), a planetary constants kernel | | (.TPC),a SPICE leap seconds kernel (.TLS), and a | | Moon ephemeris table (.TAB). | | | |- [EME50] Spacecraft state vectors in the Selenocentric | | Earth Mean Equatorial (1950) coordinate system. | | | |- [TRAJECT] Spacecraft position vectors in multiple | | coordinate systems. | | | |- [SUNPULSE] Spacecraft Sun pulse files which give | | | Sun pulse times and time uncertainties, | | | organized into one-month subdirectories | | and 10-day sub-subdirectories (the latter | | are not shown in this tree). | | | |-[99_04APR] | |-[99_05MAY] | |-[99_06JUN] | |-[99_07JUL] | | |- [INDEX] Contains index tables for all files on the disk, | for the four main types of data on the disk, and | for the volume set to date.
Driver and Hardware Information
This disk has been formatted according to the ISO standard for DVD production (9660) with level 1B compliance. Any system which complies with this standard (all of them should) should be able to access this disk.
The person most directly responsible for the construction and release of this disk 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 disk include Dr. Mark Sharlow and Dr. Raymond Walker, the PDS/PPI Node manager. For questions or problems regarding this disk, 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 disks available from the PDS, please contact the 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.