Dawn Mission to Vesta and Ceres
Level 5
SPC Shape Models of Vesta and Ceres
Archive Volume Software Interface Specification
Version 2.2
October 19, 2018
CHANGE LOG
|
DATE |
CHANGES |
REASON |
REVISION |
|
02/26/2016 |
Original |
|
1.0 |
|
04/14/2016 |
Clarifications in data sources, data set identifiers, volume identifiers |
Updated from initial comments from DSC/PDS |
1.1 |
|
03/23/2018 |
Remove DSK |
DSKs will be archived by NAIF |
2.0 |
|
04/25/2018 |
Added ancillary folder |
Update for volume creation |
2.1 |
|
10/19/2018 |
Renamed ancillary folder to geometry folder; various grammatical fixes |
Update from peer review |
2.2 |
TABLE OF CONTENTS
2. REDUCED DATA RECORD ARCHIVE OVERVIEW
4. NOTE ON DIGITAL SHAPE KERNELS (DSK).
5. RELEVANT DATA ARCHIVED AT OTHER SITES
ACRONYMS AND ABBREVIATIONS
ASCII American Standard Code for Information Interchange
CK C-Kernel (Attitude orientation kernel)
DOY Day of Year
DSC Dawn Science Center
DSK Digital Shape Kernel
DTM Digital Terrain Map
FK Frame Kernel
ICQ Implicitly Connected Quadrilateral
JPL Jet Propulsion Laboratory
LSK Leap Seconds Kernel
NAIF Navigation Ancillary Information Facility
NASA National Aeronautics and Space Administration
PDS Planetary Data System
SIS Software Interface Specification
SPC Stereo-photoclinometry
SPK Spacecraft and Planetary (Ephemeris) Kernel
This Software Interface Specification (SIS) describes the format and content of the Dawn Mission to Vesta and Ceres (Dawn) shape model archive delivered by the Dawn Gravity Science Team. The Dawn SPC Ceres shape model dataset represents the archive of the Ceres shape model derived from the Framing Camera (FC) instrument onboard the Dawn spacecraft. The Dawn SPC Vesta shape model dataset represents the archive of the Vesta shape model. The archives are generated by the Dawn Gravity Science Team and the Dawn Science Center (DSC). It is maintained and distributed by the Planetary Data System (PDS).
This archive contains data products derived from images taken by the Dawn spacecraft acquired while the spacecraft was conducting science observations around the respective target. This SIS describes the format and content of the Dawn shape model archives delivered by the Gravity Science Team. The data are assembled into archives by the Gravity Science Team and delivered to the Dawn Science Center (DSC). The DSC delivers the completed archives to PDS. The table below highlights the details of each archive.
|
Target |
Data Set ID |
Volume ID |
|
Vesta |
DAWN-A-FC2-5-VESTASHAPESPC-V1.0 |
DWNVSPC_4_01 |
|
Ceres |
DAWN-A-FC2-5-CERESSHAPESPC-V1.0 |
DWNCSPC_4_01 |
The “01” portion of the Volume ID will be incremented with the release of any future volumes containing new versions of the shape model.
The specific data products included in these archives are:
· Implicitly Connected Quadrilateral (ICQ) files: ASCII-formatted shape model
The Framing Camera (FC) is a multispectral CCD imager in a refracting telescope that also serves as optical navigation camera for the NASA Dawn mission to the asteroids 4 Vesta and 1 Ceres. The camera consists of two identical units, FC1 and FC2, which are mounted side-by-side on the +Z deck of the spacecraft.
For the full description of the Framing Camera instrument, please refer to the fc2_instrument.cat and DATASET.CAT files in the CATALOG directory.
The derived data are stored in the DATA folder in one subdirectories. The ICQ files are ASCII files with detached PDS labels describing the format. The table below describes the data products contained in these directories.
|
File |
Abbrev. |
File Type |
Source of Files |
|
Implicitly Connected Quadrilateral |
ICQ |
ASCII |
Dawn Science Team |
Implicitly Connected Quadrilateral files
The models were originally prepared in the Implicitly Connected Quadrilateral (ICQ) format, and files are provided in the DATA/ICQ directory. The filenames are of the form TTTTT_xxxyymmdd_qqqq.ICQ, where ‘TTTTT’ is the applicable body (VESTA or CERES), 'xxx' is the origin of the shape model (nominally SPC, for Stereo-photoclinometry), 'yy' is the creation year, 'mm' is the creation month, 'dd' is the creation day, and 'qqqq' is the resolution of the model. A text file, 'ICQMODEL.ASC', is provided in the DOCUMENT directory describes the ICQ format.
Data processing is performed by the Dawn Gravity Science Team at the Jet Propulsion Laboratory in Pasadena, CA. The images are processed using a technique called Stereo-photoclinometry to produce a shape model of the target body.
No software is included in this archive. The SPICE toolkit provides useful tools and algorithms for ancillary data processing that could help in the use of these products of and is located at the NAIF PDS node naif.jpl.nasa.gov.
See Section 2.2.1 for file naming conventions in the description of each file type.
Every file in this archive is accompanied by a PDS label. The label is either attached (embedded in the file) or detached (separate file with same name except for extension ‘.LBL’). Depending on the file type, the detached label may provide the content and structure of the file. Labels are structured in the PDS KEYWORD=VALUE fashion. A description of the keywords may be found on the web at http://pds.nasa.gov/tools/ddlookup/data_dictionary_lookup.cfm.
The Dawn SPC Shape Model Data Archive uses the following standard keywords and values, consistent across the archive:
|
Keyword |
Dawn Standard Values |
|
DATA_SET_ID |
DAWN-A-FC2-5-VESTASHAPESPC-V1.0 DAWN-A-FC2-5-CERESSHAPESPC-V1.0 |
|
DATA_SET_NAME |
VESTA SPC SHAPE MODEL V1.0 CERES SPC SHAPE MODEL V1.0 |
|
INSTRUMENT_HOST_ID |
DAWN |
|
INSTRUMENT_HOST_NAME |
DAWN |
|
INSTRUMENT_ID |
FC2 |
|
INSTRUMENT_NAME |
FRAMING CAMERA 2 |
|
INSTRUMENT_TYPE |
FRAME CCD REFRACTING TELESCOPE |
|
MISSION_NAME |
DAWN MISSION TO VESTA AND CERES |
|
TARGET_NAME |
1 CERES, 4 VESTA |
|
VOLUME_ID |
DWNVSPC_4_01 DWNCSPC_4_01 |
|
VOLUME_SERIES_NAME |
DAWN |
|
VOLUME_SET_ID |
USA_NASA_PDS_DWNVSPC_4_01 USA_NASA_PDS_DWNCSPC_4_01 |
|
VOLUME_SET_NAME |
DAWN SPC VESTA SHAPE MODEL DAWN SPC CERES SHAPE MODEL |
|
VOLUME_VERSION_ID |
VERSION 1 |
The Dawn SPC Shape Model Archives have the following directories:
v Root directory
Ř CATALOG
Ř DOCUMENT
Ř DATA
§ ICQ
Ř GEOMETRY
Ř INDEX
The contents of the directories are described below.
This directory is the core directory on which the rest of the archive is built. It contains the following files:
1. AAREADME.TXT: Human readable description of the archive contents
2. ERRATA.TXT: Human readable list of corrections and other comments regarding the archive
3. VOLDESC.CAT: Description of the contents of the volume
This directory contains recommended SPICE data kernel set for use with the ICQ files. The GEOMINFO.TXT in the GEOMETRY folder contains details on the contents of the GEOMETRY directory.
This directory contains descriptions of the dataset, mission, instrument, and spacecraft. They are all ASCII stream files. It contains the following files:
1. CATINFO.TXT: Description of the directory
2. DATASET.CAT: Overview of the RDA
3. fc2_instrument.cat: Overview of the Framing Camera Instrument
4. dawninsthost.cat: Overview of the Dawn spacecraft
5. dawnmission.cat: Overview of the Dawn Mission to Vesta and Ceres
6. REF.CAT: References for the archive
This directory contains the corresponding documentation to help the end user use and interpret the data included in this archive. The following documents are included:
|
Filename |
Format |
Description |
|
DOCINFO.TXT |
text |
Description of the directory |
|
DAWN_SPC_SHAPE_MODEL_SIS |
HTML, PDF |
This document |
|
ICQMODEL |
text |
Description of the ICQ shape model format |
|
SPICE_OMNIBUS_MM_SIS |
HTML, PDF |
Description of the SPICE system and where to get more information |
This directory contains the following files:
1. INDEXINFO.TXT: Description of the directory
2. INDEX.LBL: Detached label describing INDEX.TAB
3. INDEX.TAB: Table listing all data products in the RDR archive
The
DATA directory contains the primary data. It contains the following
subdirectories and file types:
|
Directory |
File Type |
Contents |
|
ICQ |
Implicitly Connected Quadrilateral file |
Shape models in the ASCII ICQ-formatted file |
Digital Shape Kernels (DSK) are a SPICE-compatible format of a shape model. The shape models included in this archive are also available in the DSK format on the Navigation and Ancillary Information Facility (NAIF) website. Section 5.1 details the location of the NAIF node for the Dawn mission to Vesta and Ceres.
The Navigation and Ancillary Information Facility (NAIF) is the navigation node of the PDS. NAIF provides the archives for spacecraft navigation, attitude, events, clock conversion, and planetary ephemerides for most NASA missions. Additionally, NAIF provides the SPICE toolkit, containing useful algorithms to utilize and manipulate data NAIF provide.
The NAIF PDS archive for Dawn is located at:
· naif.jpl.nasa.gov/pub/naif/pds/data/dawn-m_a-spice-6-v1.0/
· Ryan S. Park, Chair of the Dawn Gravity Working Group, NASA Jet Propulsion Lab
· Dustin R. Buccino, NASA Jet Propulsion Lab