Data Set Overview:The Cassini ISS Cartographic Map archive dataset consists of cartographic map sheets of Saturn's icy satellites Dione, Enceladus, Iapetus, Mimas, Phoebe, Rhea, and Tethys. Additionally, the archive volumes contains a global mosaic image, the processed tile imagesused to create the cartographic map sheets, PDS label files, relatedCassini and ISS instrument documentation, index files of the maps and images for use in data management systems, and other helpful andrequired PDS files.More information on the details of this volume can be found in thedocument directory and the aareadme.txt file at the root level of this volume.Processing:The cartographic maps were created from images taken by Cassini witha very small number of images from Voyager-1 and Voyager-2 used to fill in any gaps. Images taken from all three missions are available online from the Planetary Data System (PDS) Imaging Node[http://pdsimaging.jpl.nasa.gov]. Though the Cassini-ISS camera takes images using many different filters, the only images used were taken with the filters CL1, CL2 or GRN, as these images show similar contrast.Processing begins with the conversion of images from the PDS format to the VICAR (Video Image Communication and Retrieval) format, thenfollowed by the radiometric and geometric calibrations using standard VICAR programs [available from the website http://rushmore.jpl.nasa.gov/vicar.html]. Next is conversion of the images to digital maps, which requires precise orbit and pointing data for each image. For the Cassini mission, spacecraft position and camera pointing data are available in the form of SPICE kernels [http://naif.jpl.nasa.gov]. While the orbit information is sufficiently accurate to be used directly for mapping purposes, the pointing information must be corrected using limb fits. High resolution images not containing the limb were registered to limb images to improve the pointing. For the Cassini maps, newly derived tri-axial ellipsoid models were used to calculate the surface intersection points.Digital maps are prepared in simple cylindrical projection, a special case of equirectangular projection. The mapping cylinder is tangent to the equator of the sphere, the longitude range is 0 to360 W and latitude range -90 to 90. The prime meridian is in thecenter of the map. For Cassini images, a photometric correction using the Henyey-Greenstein function was applied to the image data before mosaicking. The inner Saturnian satellites are best described by tri-axial ellipsoids as recommended in the report of the International Astronomical Union (IAU). However, to facilitate comparison and interpretation of the maps, ellipsoids were only used for the calculation of the ray intersection points, while the map projection was done onto a sphere with the mean IAU radius. The final step of the image processing is the combination of all mapprojected images to a homogeneous mosaic. Special care must be takento handle the different ground resolutions within overlapping regions and the variable illumination conditions in the different images in order to minimize the loss of high-resolution image information and contrast. Data:Map Sheet PDF Files-------------------The full cartographic mapping product for a particular target body consists of one or more cartographic map sheets. A map sheetwill contain one or more images of different projections of the body. Also included on the map sheet is text information describingthe index of original images used to make the map, image processingused, a summary of the map projections, references, and contactinformation. These map sheets are stored as PDF (Portable Document Format) files. More information about PDF can be found in the 'Software' section below.Tile Image VICAR Files----------------------All tile images are in VICAR image format. More information about this format and software that can be used to view it can be found in the 'Software'section below.Each VICAR image file is accompanied by an attached ASCII PDS label.The label consists of ASCII 'keyword:value' pairs describing theimportant characteristics of the image.Image Index Table-----------------The index table files contain keyword information about each dataproduct (images and maps) on the volume. This file consists of fixed-length records in ASCII character format.Each line is a record containing all the keywords for a particulardata product on the volume. Fields in a record are delimited by commas. Non-numeric fields are enclosed in quotes and left-justified, whereas numeric fields are not enclosed by any characters and are right-justified. Multi-valued fields are enclosed in brackets and each item in that field is separated by a comma.The corresponding label files for each index file details the keyword name, data type, start byte, number of bytes, and format so that keywords can be easily referenced and the file can be properly read into a database.Ancillary Data:The Cassini Project produces SPICE files (spacecraft positions,planetary positions and constants, processed pointing geometry,spacecraft clock versus universal time, etc.) for use in observationplanning and in calculating many of the image keywords populating theindex files on this volume. These SPICE files are not included in this ISS data archive but can be obtained from the PDS NAIF node. Other ancillary files include the software interface specifications related to the production of this archive volume and a list of published references that can provide a thorough discussion of the ISS science goals and objectives and ISS camera instrument.Coordinate System:The coordinate system adopted by the Cassini mission for satellite mapping is the IAU 'planetographic' system, consisting of planetographic latitude and positive west longitude, but because a spherical reference surface is used for map projections of the satellites, planetographic and planetocentric latitudes are numerically equal.Software:The image processing software used to create the EDR image files andcartographic mosaics is called VICAR (Video Image Communication And Retrieval). VICAR is an entire system of software, formats, and procedures for image storage and processing and was developed and is maintained by JPL's MIPS. A full explanation of VICAR, its standards,software and reference information can be found at the website:  http://www-mipl.jpl.nasa.gov/vicar/Information on tools for visualizing VICAR images can also be found there. For example, the PDS-provided NASAview tool can be downloaded from the PDS site (http://pds.jpl.nasa.gov) and used to view the raw images.The map sheet files are stored in Adobe PDF (Portable DocumentFormat). PDF is a proprietary format of Adobe Systems Incorporatedthat is frequently used for distributing documents. Adobe offers a free downloadable reader, Acrobat Reader, from their website at http://www.adobe.com. Be sure to download the latest version of Acrobat Reader to view the PDF files on the this volume.Media Format:This volume is being delivered to the Planetary Data System (PDS)using DVD media. Formats are based on standards for such productsestablished by the PDS [PDSSR1992].

Confidence Level Overview:The quality and completeness of the cartographic maps are determined by a careful visual inspection by the ISS team and then a validation by the US Geological Survey (USGS).The quality and completeness of the archive volumes generation processis determined by the accuracy of the archive generation softwarewritten and employed by the CICLOPS team. This archive generation software parses information from the data products to generate the index files and then copies the appropriate image files, map files and static information files prior to creating the archive volume disk. An interface to the software allows a human user to choose which volume to generate. The static information files are updated as needed. These files are stored in a CVS file repository and are reviewed as updated. An additional CICLOPS-generated script is then run on the final volumes to check for obvious mistakes or omissions. Additional validation software is run by PDS to ensure the disk conforms to PDS standards. Review:In order to ensure PDS-compliant products, the map volumes are validated by a collaborative effort between the ISS/CICLOPS team, the Imaging and Central Nodes of the PDS, and non-Cassini imaging scientists. The ISS/CICLOPS team is responsible for producing PDS-compliant map volumes, while the PDS personnel are responsible for ensuring that the map volume(s) meet PDS standards. Validation is performed on each volume by PDS using their validation tools. ISS/CICLOPS-developed operational volume verification tools and procedures are also utilized prior to delivery to PDS Imaging Node.Together these verification checks ensure PDS-compliant map volumes.A thorough review of a sample map volume and directory files isbeing performed prior to the start of volume production. The peerreview of sample volume is conducted by PDS. The review servesto validate the volume for proper structure, format, completeness,and science usability. Any deficiencies in the reviewed mapvolume found are corrected and resolved. When all correctable errorshave been resolved, production of the map volumes proceeds andfurther validation is performed on a spot check basis by the both thePDS and the ISS/CICLOPS team. Non-correctable errors are described in the evolving errata file, errata.txt, included on each mapvolume in the Root Directory.Data Coverage and Quality:Imaging of the medium-sized icy satellites is ongoing and will continue until the end of the Cassini mission, making it possible to improve the image mosaics during the tour. Global mosaics consistof mostly high-resolution Cassini images. Voyager images are used to fill any small gaps. The global mosaics are usually produced using images of a similar resolution. However, some areas of the satellites are imaged at very high resolution. These higher resolution images were processed to separate mosaics. The data set of Phoebe is the only one that is complete, as no more high-resolution images are expected during the mission. Also, we will not obtain new high-resolution Enceladus images until 2008. Therefore standard maps were generated for these two satellites.The Cassini spacecraft will continue its imaging campaign through the Saturnian system. Satellite close flybys are scheduled for Tethys, Dione, Rhea, Iapetus, and Enceladus within the nominal mission ending in 2008. These data will be used to further improve the existing semi-controlled mosaics and maps and also to update or calculate initial global geodetic control networks of the Saturnian satellites for controlled orthophoto mosaics.A semi-controlled mosaic is composed of corrected or uncorrected prints laid such that major ground features match their geographicalcoordinates. In contrast, an uncontrolled mosaic is composed of uncorrected photographs, the details of which have been matched from print to print, without ground control or other orientation. Accurate measurement and direction cannot be accomplished or guaranteed.Limitations:The most up-to-date ellipsoid and mean radius for a body are usedin the calculations (for instance, to calculate the surfaceintersection points and to fit the limb if it is available).However, for bodies that are not good ellipsoids, like Phoebe,this is a limitation that affects the accuracy of the mosaic.The latitude and longitude errors on the Phoebe map is a fewdegrees. For all the other bodies, the errors are much smaller.