SBN SBN Archive File Types

There are several different file types, indicated by the file extension, found in the SBN archives and in the data set review pages. They include:

.asc
These are plain ASCII text files which are most often found in the document/ directory of a data set. Many times they accompany a .doc file and contain identical information for those users who can not open a .doc files. They can be opened using a standard text editor or a browser.

.cat
These are PDS required catalog files which supply high-level information about the data set for use in the central PDS catalog and will be found in the catalog/ directory. They include things like an overview of the data set, its processing history, and other information associated with the mission or subsequent data reduction which might be of interest. They are ASCII text files and can be displayed with any standard text editor. PC users can not open them with a browser if the files have been downloaded to their PC.

.csv
These are Comma-separated Variable format ASCII spreadsheets. They may be found in the data/, document/, calibration (calib/), or index/ directory. They can be opened using any standard text editor, browser, or CSV compatible spreadsheet program.

.dat
The .dat suffix indicates a binary data file. They may appear in the data/ directory and have an associated PDS label. Some sort of software is typically required to view these files. The SBN utility for IDL, ReadPDS should read and display these files. Check for a "software" directory within the dataset; it may contain special or additional software to read the binary data files.

.doc
These are Microsoft Word document files which may be found in the document/ or calibration (calib/) directory and describe aspects of the data reduction or details pertaining to the calibration pipeline. Typically, they are accompanied by a plain text version of the file (.asc file) or a .pdf version and a PDS label. They can be opened using Microsoft Word or other word processing software that is capable of reading a Microsoft document.

.fit
Flexible Image Transport System (FITS) files are data files, and the most common image data format in the SBN archive. They may contain images, spectra, and/or tables. All FITS files have both a header and data in the same file and may have multiple file extensions. They also have separate PDS labels. FITS files should be readily interpreted by any standard FITS image display software or pre-existing routines in standard analysis packages (like IRAF, IDL, MatLab, Mathematica, etc.). Some links are provided for downloading display software:

Note that the PDS labels which correspond to the FITS image files will contain a pointer and object description for the FITS header as well as the image.

.gif
Graphics Interface Format files are lossless compressed image files which may appear in the document/ or calibration (calib/) directory. They will be accompanied by a PDS label and can be opened using most image manipulation software (like XV, Photoshop, etc.) or a browser.

.img
These are PDS binary image files with attached or detached PDS labels. They may be found in the /data directory. They can be displayed using an SBN utility for IDL, ReadPDS.

.jpg
These are lossy compressed image files which may appear in the document/ or calibration (calib/) directory. They will be accompanied by a PDS label and can be opened using most image manipulation software (like XV, Photoshop, etc.) or a browser.

.lbl
The PDS label files describe the contents of each dataset in detail, field-by-field, and are a PDS archive requirement. This includes a physical description of the storage format as well as a logical explanation of the significance or content of each field. Detached labels accompany most files on the volume and are ASCII text, so they can be read with any standard text editor or browser.

.pdf
These are Adobe Portable Document Format (PDF) files. They may be found in the document/ or calibration (calib/) directory and should have an associated PDS label. They can be opened using Adobe Acrobat Reader.

.pds
The PDS is planning to start archiving spectral cubes. The .pds extension is just a place holder for these spectral cubes. The PDS data cubes will be data files requiring specialized software to display and manipulate. The USGS has developed and made available software for this purpose. Integrated Software for Imagers and Spectrometers (ISIS) combines basic capabilities of image processing, analysis and display of 2- and 3-dimensional data with specialized planetary cartographic functionality.

.png
These are Portable Network Graphics images, a bitmapped image format using lossless compression. They may appear in the document/ or calibration (calib/) directory. They can be opened using most image manipulation software (like XV, Photoshop, etc.) or a browser.

.tab
These are ASCII table files. Table files may be found in most directories. The tables should be accompanied by PDS labels. The tables should be displayable in a standard text editor or browser.

.tar
These files are tape archive format files, which are used to simplify storage and downloads of large data sets. They preserve the directory structure of the data set volume. Data reviewers and archive users may encounter .tar files when downloading an entire data directory or a large set of documentation. Tar files can be opened by using GNU Tar software or a similar program. If the .tar file contains FITS files, do not use WinZip because it may corrupt the FITS files.

.tgz
These files are tape archive format (tar) files that have been compressed by gzip (GNU zip). This type of file is used to simplify storage and downloads of large data sets while preserving the directory structure. Data reviewers and archive users may encounter .tgz files when downloading an entire data directory or a large set of documentation. Tgz files can be opened by using:

.tif
Tagged Image File Format files are image files that may appear in the document/ or calibration (calib/) directory. They can be opened using most image manipulation software (like XV, Photoshop, etc.) or a browser.

.txt
These text files are flat ASCII files, but usually denote documentation files which either a) have no accompanying PDS label; or b) have a minimal PDS label attached to the top of the file. They provide additional information to explain archive directories and contents. They can be read with any standard text editor or a browser.

.xls
These are Microsoft Excel Spreadsheet files which may be found in the document/ or calibration (calib/) directory. They may contain tabular data specific to the instrument and data reduction or details of the data acquisition. Typically, they are accompanied by a .pdf version of the file and a PDS label. They can be opened using Microsoft Excel.

.zip
Zip files are compressed files, used when downloading large files. Data reviewers and archive users may encounter .zip files when downloading an entire data set, data directory or a large set of documentation. Zip files can be opened by using Zip software, GNU Zip software, WinZip or a similar program.

SPICE files
Spacecraft, Planet, Instrument C-Matrix Events (SPICE) is an information system focused on solar system geometry, time, and related information. The Navigation and Ancillary Information Facility (NAIF) of the PDS has documentation, tools, tutorials, and sub-routines to read SPICE kernels (in C, Fortran, or IDL) for mission SPICE data. When supplied with a data set, SPICE files are in their own directory.

Note: All ASCII files, whether they are data files or PDS labels, have fixed-length records which end with a carriage-return/linefeed delimiter. The data may be downloaded to your home system, or, in the case of ASCII files, browsed on-line.

Last update: 05 Mar 2008, sam.