Naming conventions and Directory Structure

Raw image files are named Cnnnnnnn.IMQ, where ‘nnnnnnn’ is the FDS count (without a decimal point) and “IMQ” indicates that the file is a compressed image. Generally, for the Jupiter encounter, images beginning with 1 are from Voyager 1 and those beginning with 2 are from Voyager 2. Similarly, for the Saturn encounter, images beginning with 3 are from Voyager 1 and those beginning with 4 are from Voyager 2. The Voyager 2 FDS clock was reset prior to the Uranus and the Neptune encounters. Consequently the FDS counts, and therefore filenames, for these encounters are numerically smaller than those for the Saturn encounter.

The images are stored in subdirectories named for the nominal target of the observation. Many images contain more than one target and some images missed their intended target, so the directory structure provides nothing more than general guidance about the contents of the images.

For details on the volume structure and file naming conventions, please review a Voyager ISS AAREADME.TXT file (especially section 4). This file (with minor header variations) appears in the root directory of every volume.

This link, Calibration notes provides references for Voyager image calibration.

The following links are to hypertext versions of representative VOLINFO.TXT, DATASET.CAT and REF.CAT files. These files are included on every volume.

• Volume organization and file formats.
• Data set description.
• Data set references.

This link provides access to the narrow angle and wide angle camera descriptions.

Getting the Data You want

• Use OPUS, our versatile search engine to find and retrieve specific Voyager ISS data products using a wide range of criteria.

  • Search results are provided with thumbnail images for each observation, and include options to download compressed raw images, thumbnail images, tables of associated metadata, and if available versions of the images in various stages of processing from uncompressed raw images through fully calibrated and geometrically corrected. User selected data files can be bundled as zip files for easy downloading.

• The table below gives direct online access to the individual volumes.

  • Clicking on the VOLUME_ID will take you to the root directory of the volume.

  • To download an entire volume, right click on that volume’s “Compressed Volume” link in the second column.

The compressed volumes are provided in .tar.gz format. For information on opening files of this type, click here.

• Clicking on the corresponding “Browse” link will take you to the browse directory for the specified volume. Most volumes contain their own browse images. The exceptions are:
  • Browse images for VG_0001 & VG_0002 are on VG_0003.
  • Browse images for VG_0004 are on VG_0005.
  • Browse images for VG_0006 & VG_0007 are on VG_0008.

  • Browse images for VG_0009, VG_0010 & VG_0011 are on VG_0012.

  • Clicking on IMGINDEX.TAB will take you to the index file for that volume. The index file is a twenty two column, ASCII table listing each image on the volume along with some information extracted from that image’s label file. Descriptions of the columns can be found in the INDEX.LBL file in the INDEX subdirectory on each volume.