PDS4 Bundle for Magellan Global Vector Data Record (GVDR) Data

This bundle contains Magellan data migrated from the PDS3 volume. The bundle includes composite radar scattering functions derived 
from Magellan synthetic aperture radar, altimetry, and radiometry. Results are stored in ASCII and binary tables linked to pixels 
with 18.225 km resolution. Pixels are organized in sinusoidal equal area, Mercator, north polar stereographic, and south polar 
stereographic projections.

The bundle is organized into the following collections:

- GVDR data collection in the gvdr directory. Data are divided into subdirectories based on projection type. 
- Two document collections, one in the document directory containing the software interface specification and tiling scheme documents, 
  and the other in the catalog directory containing the PDS3 catalog files.
- Miscellaneous collection for the PDS3 index files located in the index directory.

Each product in this bundle is described by a PDS4 label in a separate file with the same name as the file described by the label but 
with the extension .xml. PDS4 labels are XML (eXtended Markup Language) files that conform to the PDS4 Information Model XML schema at 
https://pds.nasa.gov/pds4/schema/released/. The PDS4 labels are best viewed in an XML-aware text editor, and may be used by software 
that can manipulate XML documents.

Note that the PDS4 labels and other PDS4 products are merged with the PDS3 volume such that all the PDS3 files and directories are 
preserved. Thus, users who want access to the PDS3 labels can continue to use them. All data products have been given PDS4 labels. 
Some PDS3 files remain but are not considered part of the PDS4 bundle, e.g. aareadme.txt and voldesc.cat files in the root directory 
of this bundle, among others.

The software directory has remain unchanged since the PDS3 version. It contains both source code and compiled programs to read the 
GVDR data files. These files are not considered part of the PDS4 bundle but may be useful to users.

As noted above, GVDR data are divided into subdirectories based on projection type. Note that the names of the data files are the 
same for each projection, but the contents differ. To preserve usability of the PDS3 labels and software, it was decided to leave the 
file names as is. Users should make note of the data source directory when downloading the files to avoid confusion.

This bundle was created and archived by the Geosciences Node of the Planetary Data System. Questions about this bundle may be directed 
to geosci@email.wustl.edu.