PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM ^TEXT = "AAREADME.TXT" OBJECT = TEXT PUBLICATION_DATE = 2016-09-01 NOTE = "AAREADME.TXT describes this volume." END_OBJECT = TEXT END Volume DWNVSPG_2 Dawn FC2 Vesta Encounter HAMO Digital Terrain Model (DTM) SPG Data Set DAWN-A-FC2-5-VESTADTMSPG-V1.0 ============================================================================== Brief Disk Description ============================================================================== This volume contains the Vesta digital terrain model (DTM) based on the Dawn High Altitude Mapping orbit (HAMO) Framing Camera 2 (FC2) images and derived by using the stereo photogrammetry (SPG) method. The HAMO DTM covers approximately 95% of the Vesta surface (few permanently shadowed areas near the poles required interpolation). The a DTM has a lateral spacing of ~70 m/pixel (64 pixel/degree) and a vertical accuracy of about 6 m. A global DTM is provided in an equidistant cylindrical projection and hemispheric DTMs are provided for both polar regions as stereographic projections. The DTMs are formatted as images where the DN values give the height in meters above a reference sphere of 255.0 km. At Vesta there were two HAMO science phases, both at ~700 km altitude. During the first HAMO (HAMO-1: September 29 - November 1, 2011) Dawn acquired approximately ~2,675 clear filter images with an average image scale of about 63 m/pixel [PREUSKERETAL2011]. At this time, Vesta was in southern summer and most of the northern hemisphere above 35-40 degrees north latitude was poorly illuminated. HAMO-1 consisted of six cycles with the first and last at Vesta center pointing and the other four cycles at various off-nadir angles [POLANSKEYETAL2012]. After completing its low altitude mapping (LAMO) Dawn was allowed to have a second HAMO (HAMO-2) mapping before departing Vesta for Ceres. In HAMO-2 (June 15 - July 24, 2012) Dawn was able to acquire an additional ~2,825 clear filter images with an average image scale of about 65 m/pixel [PREUSKERETAL2014]. HAMO-2 also included six cycles with nadir and off-nadir geometries similar to those used during HAMO-1 [POLANSKEYETAL2012]. HAMO-2 occurred near the Vesta equinox providing much improved lighting conditions in the northern hemisphere. Combining the two data sets, Dawn was able to map nearly 95% of the Vesta surface. All of the various products described below use the same projections. The cylindrical projection covers +/- 90 degrees of latitude and is centered at -30 degrees Claudia double-prime longitude. The minimum and maximum longitudes are -210 and +150 degrees. The northern hemisphere stereographic projection has 90 degrees north latitude at the center and the equator at the edge. The top of projection is -30 degrees Claudia double-prime longitude and the bottom is 210 degrees with longitude increasing to the east. The southern hemisphere projection has 90 degrees south latitude at the center and the equator at the edge, -150 degrees longitude at the top and 30 degrees longitude at the bottom. For a description of the coordinate system, please refer to vesta_coordinates_131018 document contained on this archive volume at the PDS and [ARCHINAL2013]. All of the Vesta SPG DTM products have a SCALING_FACTOR of 2.0 and and OFFSET of 255000 m (as noted in the PDS product labels). Conversion from Digital Number to HEIGHT, i.e. elevation in meters, is: HEIGHT = (DN * SCALING_FACTOR). The conversion from Digital Number to PLANETARY_RADIUS in meters is: PLANETARY_RADIUS = (DN * SCALING_FACTOR) + OFFSET where OFFSET is the radius of the reference sphere. NOTE: Reading the Science Plan (DOCUMENTS/SCIENCE_PLAN/DAWN_SCIPLAN_V5_4.PDF) is critical to the understanding of the planned Vesta observations and science objectives. There are several key publications that describe the data processing, Stereo SPG DTM workflow, and Vesta science observations. These include: PREUSKERETAL2014 Preusker,F., F. Scholten, K.-D Matz, T.Roatsch, R.Jaumann, C.A. Raymond, and C.T. Russell, Global Shape of (4) Vesta from Dawn FC stereo images, Lunar and Planet. Sci. Conf. abs. 2027, 2014. http://www.hou.usra.edu/meetings/vesta2014/pdf/2027.pdf PREUSKERETAL2012 Preusker, F., J. Oberst, J. Head, T. Watters, M. Robinson, M. Zuber, S. Solomon, Stereo topographic models of Mercury after three MESSENGER flybys. Planet. Space Sci. (2011). DOI:10.1016/j.pss.2011.07.005 RAYMONDETAL2012 Raymond, C.A., R. Jaumann, A. Nathues, H. Sierks, T. Roatsch, F. Preusker, F. Scholten, R.W. Gaskell, L. Jorda, H.-U. Keller, M.T. Zuber, D.E. Smith, N. Mastrodemos, and S. Mottola, The Dawn topography investigation. Space Sci. Rev. 163, 487 (2011). DOI: 10.1007/s11214-011-9863-z /DOCUMENT/STEREO_PHOTOGRAMMETRY.PDF (this volume) POLANSKEYETAL2012 Polanskey, C., S. Joy, and C. Raymond, "Efficacy of the Dawn Vesta Science Plan", SpaceOps 2012 Conference, SpaceOps Conferences, http://dx.doi.org/10.2514/6.2012-1275915. 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_T_LAT_LONG_PROJ_TYPE.EXT where: VE is literal for Vesta PHASE PHASE is either HAMO or LAMO T is either G (global) or Q (quadrangle) LAT is the center latitude of the image LONG is the center longitude of the image PROJ is the map projection type (CYL=cylindrical, STE=stereographic DTM is literal, the image type is DTM, example: VE_HAMO_G_00N_330E_EQU_DTM.IMG Vesta HAMO global centered at 0N latitude, 330 E longitude using a equidistant cyclindrical projection for the DTM. ============================================================================== 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 ==> DWNVSPG_2 Dawn FC2 L2/L3 Vesta stereo-photogrammetric DTM DWNVSPC_2 Dawn FC2 L2/L3 Vesta stereo-photoclinometric DTM DWNCHCFC2_2 Dawn FC2 L2/3 Vesta HAMO clear mosaics DWNCHFFC2_2 Dawn FC2 L2/3 Vesta HAMO color filter mosaics DWNCLCFC2_2 Dawn FC2 L2/3 Vesta LAMO clear mosaics DWNCHSPG_2 Dawn FC2 L2/L3 Vesta HAMO stereo-photogrammetric DTM DWNCHSPC_2 Dawn FC2 L2/L3 Vesta HAMO stereo-photoclinometric DTM DWNCLSPG_2 Dawn FC2 L2/L3 Vesta LAMO stereo-photogrametric DTM DWNCLSPC_2 Dawn FC2 L2/L3 Vesta LAMO stereo-photoclinometric DTM ============================================================================== 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 PDS images (.IMG, binary) with attached PDS3 labels. 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. DWNVSPG_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 JPG images 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. | |- [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. | |- [GEOMETRY] Contains a SPICE planetary contants kernel (PCK) that is | consistent with the DTM model being archived. | |- [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 frank.preusker@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.