PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM ^TEXT = "AAREADME.TXT" OBJECT = TEXT PUBLICATION_DATE = 2015-02-13 NOTE = "AAREADME.TXT describes this volume." END_OBJECT = TEXT END Volume DWNVFC2_2 Dawn FC2 High Level (2/3) Vesta Encounter Mosaics ============================================================================== Brief Disk Description ============================================================================== This data set includes various Vesta global mosaics derived from images acquired by the Framing Camera 2 (FC2) on the NASA Dawn spacecraft at the high and low altitude mapping orbits (HAMO and LAMO). Data are provided in cylindrical and polar stereographic projections. In addition to the mosaics, the flatfield and stray light correction images used during the processing of the raw images are provided. Dawn mission is equipped with two identical framing cameras (FC1 & FC2) [SIERKSETAL2011] which have one clear filter and seven band pass filters. At Vesta, only the FC2 was used to acquire science images while the FC1 was held in reserve. Clear filter images which were taken during HAMO were used to produce a global mosaic of the illuminated part of Vesta with a resolution of ~60m/pixel [ROATSCHETAL2012]. Dawn orbited Vesta in 6 cycles between the end of September and early November 2011 (HAMO-1) and another 6 cycles between late June and the end of July in 2012 (HAMO-2). A cycle is a single complete mapping of surface at a fixed off-nadir attitude. The framing camera took about 2500 clear filter images with a resolution of about 60 m/pixel during each of these mapping phases. The images were taken with different viewing angles and different illumination conditions in order to provide input to the stereo-photogrametric [PREUSKERETAL2012] and stereo-photoclinometric analyses of the Vesta topography. Images from one cycle (HAMO-1, cycle 3; HAMO-2, cycle 6 ) were selected for the mosaicking process to have similar viewing and illumination conditions. HAMO-1 occurred during the northern winter and HAMO-2 occurred during the northern spring so the southern hemisphere was mosaicked using HAMO-1 images while the north used images acquired during HAMO-2. Full color imaging (clear plus seven band pass filters) was performed twice during HAMO-1 (cycles 1 and 6) with body-center pointing. These images were used to produce the southern hemisphere portions of the various color and color ratio mosaics included with this data set. Since most of the surface of Vesta south of 30 degrees north was already imaged in full color during HAMO-1, color images were only acquired during the final cycle of HAMO-2 (cycle 6) when the northern hemisphere had its maximum illumination. Even still, the illumination was poor at the highest latitudes. Color images from HAMO-2, cycle 6 were used to create the northern hemisphere color image mosaics. Imaging in LAMO was challenging for several reasons: large gravity gradient influences on the spacecraft trajectory, and low downlink bandwidth for image return. The FC2 acquired about 10,000 clear filter images in LAMO allowing the creation of a global mosaic of Vesta with a resolution of 20m/pixel. This LAMO atlas is a higher-resolution supplementary atlas to the HAMO atlas [ROATSCHETAL2012]. The LAMO mission phase occurred during Northern winter which kept the north pole region in darkness; only 84% of the surface was illuminated and good illumination (incidence angle less than 70 deg) was only available for 66.8% of the surface [ROATSCHETAL2013]. Color images were acquired in only three bands (filters 2, 3, and 4) and over a small fraction of the surface. LAMO color mosaics are not included in this data set because of the limited surface coverage. NOTE: Reading the Science Plan (DOCUMENTS/SCIENCE_PLAN/DAWN_SCIPLAN_V4_4.PDF) is critical to the understanding of the Vesta observations and science objectives. Other critical documentation in the DOCUMENT directory include the volume SIS and calibration procedure. There are several key publications that describe the data processing and image mosaicking. These include: ROATSCHETAL2012 Roatsch,T., E. Kersten,K.-D. Matz,F. Preusker, F. Scholten, R. Jaumann,C.A. Raymond, C.T.Russell, High Resolution Vesta High Altitude Mapping Orbit Atlas derived from Dawn Framing Camera images.Planetary and Space Sciences 73, p283-286, 2012. ROATSCHETAL2013 Roatsch, T., E.Kersten, K.-D.Matz, F.Preusker, F.Scholten, S.Elgner, R.Jaumann, C.A. Raymond, and C.T.Russell, High-resolution Vesta Low Altitude Mapping Orbit Atlas derived from Dawn Framing Camera images, Planetary and Space Science 85, p293-298, 2013. PREUSKERETAL2012 Preusker,F., F. Scholten, K.-D Matz, T.Roatsch, R.Jaumann, S.P. Joy, M.D. Raymon, C.A. Raymond, and C.T. Russell, Stereo-photogrammetrically derived topography of asteroid (4) Vesta.,AGU Fall meeting,abstract 2012. JAUMANNETAL2012 Jaumann, R., D.A. Williams, D.L. Buczkowski, R.A. Yingst, F. Presuker, H. Hiesinger, N. Schmedemann, T. Kneissl, and 35 others, Vesta's shape and morphology. Science, 336, p687-690, 2012. SCHROEDERETAL2013A Schroeder, S. E., T. Maue, P.Gutierrez-Marques, S. Mottola, K.M. Aye, H. Sierks, H.U. Keller, A. Nathues, A. In-fight Calibration of the Dawn Framing Camera. Icarus 226, p1304-1317, 2013. SCHROEDERETAL2013B Schroeder, S.E., S. Mottola, H.U. Keller, C.A. Raymond, C.T. Russell, Resolved photometry of Vesta reveals physical properties of crater regolith, Planetary and Space Sciences, 85, 198-213, 2013. SCHROEDERETAL2014 Schroeder, S.E., S. Mottola, K.-D. Matz, T. Roatsch, In-flight calibration of the Dawn Framing Camera II: Flat fields and stray light correction, Icarus, 234, 99-108. ARCHINAL2013 IAU-WGCCRE-Coordinate-System-for-Vesta, http://astrogeology.usgs.gov/search/details/Docs/ WGCCRE/IAU-WGCCRE-Coordinate-System-for-Vesta/pdf ISIS Users: At the time this archive was creates, there was a problem in ISIS with understanding target names that included spaces like "4 VESTA". Future versions of ISIS will correct this problem. In the interim, ISIS users can apply the following fix: Edit the pdsImageProjection.trn translation file in the isis base data directory to include the "4 VESTA" target name. E.g. > edit $ISISROOT/../data/base/translations/pdsImageProjection.trn Add the line marked with --> in the section below: Translation = (Venus, VENUS) --> Translation = (VESTA, "4 VESTA") Translation = (Vesta, VESTA) All data are stored in the 'DATA' branch of the directory tree. In addition to the data files, ancillary information is stored in an attached PDS label. Additional copies of the data in TIFF (Tagged Image File Format)format can be found in the EXTRAS directory of this volume. Some users may find this format easier to work with in some software packages such as ArcGIS. 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. ============================================================================== File Naming Conventions ============================================================================== Data and browse images on this volume conform to the following naming convention: VE_PHASE_LAT_LONG_PROJ_TYPE.EXT where: VE is literal for Vesta PHASE is either HAMO or LAMO LAT is the center latitude of the image LONG is the center longitude (Claudia double prime) of the image PROJ is the map projection type (CYL=cylindrical, STE=stereographic) TYPE is the image type (CLEAR filter 1, FILTx where x is the filter number [2-8], and CLEM = Clementine color ratio Stray light calibration files conform to: STRAY_LIGHT_Fx.IMG where: x is the filter number (2-8) - no stray light in clear fileter 1. Flat field calibration files conform to: FC2_Fx_FLAT.IMG where: x is the filter number (1-8). There are two files for fiter 3 (FC2_F3_FLAT_DEC.IMG, FC2_F3_FLAT_INC.IMG). [SCHROEDERETAL2014] explained the reason for this as follows: "In addition, we found that the position of the dust speckles in F3 depends on the direction of the filter wheel rotation (clockwise or anti-clockwise). That is, if an F3 image acquisition follows that an F2 image, the specks are shifted with respect to their position in an F3 image following an F4 image. Thus we prepared two flat fields for filter F3, one for each filter wheel rotation direction" (increasing or decreasing). ============================================================================== Volume Set Information ============================================================================== This volume is part of the FC2 high level data volume set. This volume set includes the following volumes: Volume ID Description ------------------------------------------------------------ DWNVFC2_2 Dawn FC2 L2/3 Vesta Encounter mosaics DWNCFC2_2 Dawn FC2 L2/3 Ceres Encounter mosaics ============================================================================== Mission Facts ============================================================================== The 'Dawn Vesta Science Phases' table below provides a list Dawn Vesta Encounter mission phase start dates. ------------------------------------------------------------------------------ Dawn Vesta Science Phases ------------------------------------------------------------------------------ start date (DOY) Phase Name (ID) ------------------------------------------------------------------------------ 2011-05-03 (123) VESTA SCIENCE APPROACH (VSA) 2011-08-11 (223) VESTA SCIENCE SURVEY (VSS) 2011-08-31 (243) VESTA TRANSFER TO HAMO (VTH) 2011-09-29 (272) VESTA SCIENCE HAMO (VSH) 2011-11-02 (306) VESTA TRANSFER TO LAMO (VTL) 2011-12-12 (346) VESTA SCIENCE LAMO (VSL) 2012-05-01 (122) VESTA TRANSFER TO HAMO 2 (VT2) 2012-06-15 (167) VESTA SCIENCE HAMO 2 (VH2) 2012-07-25 (207) VESTA TRANSFER TO CERES (VTC) ------------------------------------------------------------------------------ ============================================================================== File Formats ============================================================================== The data files on this volume are formatted as VICAR2 banded images (binary) with attached PDS3 labels. Most of the images have only a single band (simple image) with the Clementine color ratio images requiring 3 bands, one each for red, green, and blue. The PDS label contains information describing spacecraft, target, and data record format. Even though the PDS labels are attached to the files, they can be viewed in a text editor. A data set description, instrument description, and other PDS documents are in .CAT files in the /CATALOG directory. Additional documentation is generally located in the DOCUMENT directory. Note for Windows users: In more recent versions of the Microsoft Windows operating system the .CAT by default is reserved as 'Security Catalog.' The .CAT files contained in this volume are ASCII text files, and can be read by any form of text editor. To make Windows open files with this name extension as text files, do the following. To make Windows open files with this name extension as text files right click the .CAT file, select with and choose a text editor to open the file. ============================================================================== Errata ============================================================================== Every effort has been made to insure that the data and documentation are of the best possible quality. However, mistakes are inevitable. 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 volume was produced. ============================================================================== Volume Contents and Structure ============================================================================== 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. DWNVFC2_2 (root directory) | |- AAREADME.TXT Describes volume contents, and organization (this file) | |- ERRATA.TXT Describes known deficiencies or caveats in the data or | on this volume. | |- VOLDESC.CAT High level description of volume contents. | |- [BROWSE] Contains a PDF plot of the data located in the DATA branch | of this volume. More information on the contents of this | directory is provided in the file /BROWSE/BROWINFO.TXT. | |- [CATALOG] PDS catalog files containing information describing the | data, instrument, instrument personnel, relevant references, | the spacecraft, and mission. More information on the contents | of this directory is provided in the file | /CATALOG/CATINFO.TXT. | |- [DATA] Contains the data files. The data are divided up into | separate sub-directories by data set. | |- [DOCUMENT] Contains documents describing the instrument, and data | acquisition, processing, and usage. More information on the | contents of this directory is provided in the file | /DOCUMENT/DOCINFO.TXT. | |- [EXTRAS] Contains files which facilitate the use of the data on the | disk, but which are not actually required for the use or | understanding of those data. A more detailed description of | the contents of this directory is provided in the file | /EXTRAS/EXTRINFO.TXT. | |- [INDEX] Contains a table of contents for all files located on this | volume, and the volume set to date. A more detailed | description of the contents of this directory is provided in | the file /INDEX/INDXINFO.TXT. ============================================================================ Contacts ============================================================================ This volume was produced for the Planetary Data System (PDS) at the Small Bodies node. The data, and associated metadata were supplied by Dr. Thomas Roatsch, DLR Berlin-Adlershof. The volume was assembled at the Dawn Science Center (DSC), by Joseph N. Mafi. For questions or problems regarding the volume, please contact Carol Neese at the PDS Small Bodies Node: Email neese@psi.edu Telephone 520-622-6300 Mail Carol Neese Planetary Science Institute 1700 E. Ft. Lowell, Ste. 106 Tuscon, AZ 85719-2395 USA For question regarding the data, please contact Dr. Thomas Roatsch of DLR: Email thomas.roatsch@dlr.de Telephone +49 30 67055-0 Mail DLR Berlin-Adlershof RutherfordstraBe 2 12489 Berlin Germany For questions regarding PDS Standards or other archives available from the PDS, please contact PDS Operator at the PDS Engineering Node (at JPL): Email pds_operator@jpl.nasa.gov Telephone 818-354-4321 Mail Planetary Data System, PDS Operator Jet Propulsion Laboratory Mail Stop 202-101 4800 Oak Grove Dr. Pasadena, CA 91109-8099 USA The PDS assumes 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. Please report errors on this disk to the Small Bodies Node of the PDS through the ERRATA reporting procedures described above.