Note that this archive is in peer-review and may not be in its final form. The current state may be viewed online at http://www-pw.physics.uiowa.edu/pds/VGPW_0201/.
This volume set is comprised of two separate data sets containing density measurements within the outer Jovian magnetosphere (outside ~20Rj) determined from Voyager 1 and Voyager 2 spacecraft. By measuring characteristic frequencies of the plasma from high-resolution wideband plasma wave spectrum data and using the equations of cold plasma theory, the density was determined.
Every effort has been made to assure 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. 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.
This volume, VGPW_0201, contains ASCII data of density measurements derived from high-resolution wideband plasma wave spectrum data taken during both Voyager 1 and 2 missions during their Jupiter flybys. This volume separates the data into Voyager 1 and Voyager 2 directories with individual day-long files in each. The Voyager 1 directory includes all available density data for Voyager 1 spacecraft event time(SCET) 1979-03-01 through 1979-03-21. The Voyager 2 directory includes all available density data for Voyager 2 spacecraft event time (SCET) 1979-07-04 to 1979-07-11. The density data has been determined from plasma wave freqeuncy measurements taken from Voyager high-resolution spectrum data. Included with the electron plasma density data are helpful parameters utilized in determining the density such as the frequencies of the plasma (including frequencies measured directly from the PWS spectrum and frequencies calculated using magnetic field data and the equations of cold plasma theory), coordinates in both ecliptic and geographic coordinate systems, to ensure full replicability.
A web browser can be used to view data on this disk in the form of Portable Network Graphics (PNG) files which are image files of density vs. time plots. Follow the link named Graphical Density Data Browser Index in AAREADME.HTM (this file) in the root directory. The browse data under the BROWSE directory consist of the "*.PNG" files. The plots are presented along with links to corresponding data files and their PDS label files.
All data files are stored under the DATA top-level directory and are organized by data set and spacecraft event time. The DATA directory branches off into:
These are ASCII day-long files named like Vnyyyyddd.CSV, where n refers to which spacecraft data is used and yyyyddd is the corresponding year and day to which the data belong. Each file is described by an associated PDS label file named like Vnyyyyddd.LBL, and the record structure is described by the file named SPREADSHEET.FMT.
General information for this volume is provided in PDS catalog files located in the CATALOG directory. The data sets are documented in:
Other PDS catalog files include:
The DOCUMENT directory contains:
The EXTRAS/SOFTWARE directory contains a Java (TM) application which may be used to produce high resolution plots of the data on this volume. See EXTRAS/EXTRINFO.TXT for more information.
All density measurements were derived from measuring characteristic frequencies from Voyager's high-resolution wideband plasma wave spectrum data. The data is in frequency vs. time spectrograms which extend from approximately 28 Hz up to 12 kHz. The high-resolution waveform data has been extensively compiled and submitted to the PDS under the following data set IDs:
which are available elsewhere within the Planetary Data System on volume sets VGPW_10xx (Voyager 1) and VGPW_20xx (Voyager 2).
Magnetic field data used in this volume were obtained from the Voyager 1 and 2 magnetometer data which has been submitted to the PDS under the following data set IDs:
which are available elsewhere within the Planetary Data System on volume sets VG_1501 (Voyager 1) and VG_1502 (Voyager 2).
This volume, VGPW_0201, contains all available density ASCII data as derived from Voyager high-resolution wideband plasma wave spectrum data from the spacecraft event time (SCET) interval 1979-03-01 through 1979-07-11. This volume will be updated only if the improvement of temporal or spectral measurement resolution becomes significant.
The disk is organized into a hierarchical directory structure. The disk is formatted according to a combination of ISO 9660, UDF, Rock Ridge (UNIX), and Joliet (Microsoft) standards in order to accommodate users on a wide variety of platforms. This volume does not contain any Extended Attribute Records (XAR). Thus, VMS users may have some problems accessing files on this volume.
The data files on this volume are ASCII text files. Browse data are provided in Portable Network Graphics (PNG) 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 V11979060.CSV is accompanied by the detached label file V11979060.LBL in the same directory. File names within this archive comply with the "27.3" convention for compliance with ISO 9660 Level 2 interchange requirements.
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, MS 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) 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 or commas. Character fields are left justified, and numeric fields are right justified. 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 spreadsheet 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 .CAT, .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.
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.CSV", 3)
indicates that the SERIES object begins at record 3 of the file 20903684.CSV, 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 = ("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.
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:
Example:^STRUCTURE = filename
^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.
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 DVD-R was published. Any changes or errors that are found after the production of this volume can be found on the PPI Node errata Web page ( http://www.igpp.ucla.edu/cgi-bin/ditdos?errata=VGPW_0201).
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.
Complete display and analysis Java (TM) application as well as the algorithm used to measure spectral peaks and cutoffs are provided in the EXTRAS/SOFTWARE directory. This software is provided as "as is" and is distributed as a service to the community.
More information is provided in the file EXTRAS/EXTRINFO.TXT.
This section describes the volume structure and naming conventions. Below is a tree diagram of the volume, followed by a description of the directory function and key files in each directory.
[VGPW_0201] Root directory
|
|- AAREADME.TXT Describes volume contents, organization, and
| use.
|
|- AAREADME.LBL Label file for AAREADME.HTM
|
|- AAREADME.HTM 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 with this volume.
|
|- VOLDESC.CAT High-level description of volume contents.
|
|- [BROWSE] Contains browse summary plots in PNG format.
| |
| |- [V1] Plots for VG1 PWS SA data.
| |
| |- [V2] Plots for VG2 PWS SA data.
|
|- [CATALOG] Information on data sets and how they are
| processed and produced, on the Voyager
| spacecraft and mission, on the PWS instruments,
| on cognizant personnel, and on references to
| related documents.
|
|- [DATA] Contains ASCII files of density data and other
| | measured parameters which constitute the primary archive.
| |- [V1] VG1 ASCII data files.
| |
| |- [V2] VG2 ASCII data files.
|
|- [DOCUMENT] Documents including the instrument description
| paper.
|
|- [EXTRAS] Bonus content not necessarily conforming to PDS
| | archive standards.
| |
| |- [SOFTWARE] Example code, plus a complete analysis
| application.
|
|- [INDEX] Contains an index of PDS label files for all
data archived on the volume.
This disk has been formatted according to a combination of ISO 9660 level 2, Rock Ridge (UNIX), Joliet (Microsoft), and UDF standards. It has been recorded on DVD-R media and should be readable on all major computing platforms hosting DVD readers.
The people most directly responsible for the construction and release of this archive volume are Chris Piker and Bradley Barnhart. William S. Kurth is responsible for the construction of the data set and has provided support for most aspects of this volume's release. PPI personnel who may be aware of issues related to this volume include Dr. Raymond Walker, the PDS/PPI Node manager.
For questions or problems regarding this volume, please contact the PDS/PPI 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 archive volumes 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.
All trademarks are acknowledged as the property of their respective owners. The producers and publishers of this archive do not endorse any commercial entities which may be mentioned for clarity.
These data were collected under the auspices of the Voyager Project. Donald A. Gurnett was the Plasma Wave Spectrometer Principal Investigator. William S. Kurth was responsible for the creation of the density data set and has played a primary role in virtually all processes associated with this volume. The archiving effort at The University of Iowa was supported by C. Piker amd B.L. Barnhart. Java software was developed by J.B. Faden and E. West.
This archiving effort was supported by the Planetary Plasma Interactions Node of the Planetary Data System.
HTML documents on this volume conform to the HTML 3.2 specification.