Data Set Information
|
DATA_SET_NAME |
VG1/VG2 SATURN IMAGING SCIENCE SUBSYSTEM EDITED EDR V2.0
|
DATA_SET_ID |
VG1/VG2-S-ISS-2-EDR-V2.0
|
NSSDC_DATA_SET_ID |
77-076A-01Q
77-084A-01W
|
DATA_SET_TERSE_DESCRIPTION |
Voyager 1 & Voyager 2 Imaging (ISS) Saturn Experiment Data
Records
|
DATA_SET_DESCRIPTION |
Data Set Overview
=================
This Voyager 1 & 2 Saturn data set is available on CD-ROM.
NASA's Voyager Project and the Planetary Data System (PDS) have
created an archive of planetary digital images acquired by the
twin Voyager spacecraft (Voyager 1 and Voyager 2). This
Voyager dataset encompasses a subset of the Experiment Data
Record (EDR) files from the Saturn encounters.
The information covers Voyager 1 and 2 at Saturn (1981),
including the planet, its satellites and rings. Important to
note is the fact that while geometry information and
calibration exists for this data set, they do not exist in the
EDR data set, but both are available separately through the
Imaging Node. Neither does the data set include starfields,
calibrations, Plasma Radio Astronomy (PRA) or Plasma Wave
Spectrometer (PWS) image-formatted information. These too are
available separately through the Imaging Node.
The complete Voyager 1 & 2 Saturn data set resides on magnetic
tape in EDR format (reference VG1/VG2-S-ISS-2-EDR-V1.0). (No
processing has been performed other than organizing the
original telemetry into raster-formatted files. The set of
images on CD-ROM are also raw, however they have been
compressed using a Huffman encoding algorithm.)
Detail Target Clarification:
There are two targets which may prove to be confusing for the
unfamiliar user; PLAQUE and CAL LAMPS, both are used as
calibration targets. PLAQUE is an image of a flat piece of
metal illuminated by the sun. CAL LAMPS are lamps inside the
camera used for illumination.
The target DARK is a dark current image when the camera mode is
BODARK and the exposure is zero. DARK SKY and SKY are
shuttered images, non-zero exposures looking at dark sky.
SCAT LIGHT images are used to measure how much light is
scattered in a particular direction.
In addition to the images, supplemental information exists on
the CD-ROMs. This includes documentation about the
organization and contents of the disk. Software source code is
included to provide programmers with tools to process the image
files. There are browse images, sub-sampled versions of the
full-resolution images, which allow users to rapidly view the
archive collection with their interactive display. Finally,
there are image index files containing information about the
images stored in the archive.
Definition Clarification:
Planetodetic latitude of a point on the planet surface is the
angle between the surface normal and the equatorial plane. For
a spherical body, the latitude is incidental to the
planetocentric latitude.
The p5 point is one of 6 static points on all images. It is
the point located in the center of the image. The p1 point is
located in the top left corner, p2 top right corner, p3 bottom
left corner, p4 bottom right corner, p5 center, p6 center right
edge. If the target is not on the p5 point then tat point does
not have latitude and longitude coordinates associated with it
nor does the target have a p5 point.
The spacecraft coordinate system is a coordinate system defined
by the spacecraft structure. The antenna points along the +z
axis, the booms are along the +y and -y axes, creating a unique
coordinate system for each spacecraft.
The Canopus coordinate system is the coordinate system defined
by one axis pointing at Canopus, one pointing at the Sun and
one pointing somewhere else.
These systems are not used for describing images or points on
images. Because our interest is in where the pixels lie, not
relative to the spacecraft or stars but relative to the
target's own system.
Processing Level Id : 2
Software Flag : N
Processing Start Time : 1988-12-01
Processing Stop Time : 1989-03-31
Parameters
==========
Data Set Parameter 'DATA NUMBER'
--------------------------------
Data Number is an integer expressing the digital value of an
experiment's telemetry data.
Sampling Parameter Name : PIXEL
Data Set Parameter Name : DATA NUMBER
Data Set Parameter Unit : DIMENSIONLESS
Source Instrument Parameters
============================
Instrument Host ID : VG1
Data Set Parameter Name : DATA NUMBER
Instrument Parameter Name : RADIANCE
Important Instrument Parameters : 1
Instrument Host ID : VG2
Data Set Parameter Name : DATA NUMBER
Instrument Parameter Name : RADIANCE
Important Instrument Parameters : 1
Processing
==========
Processing History
------------------
Source Data Set ID : FRAMSINK
Software : VIMBUILD
Product Data Set ID : UNPROCESSED DATA RECORD
Source Data Set ID : UNPROCESSED DATA RECORD
Software : MERGE
Product Data Set ID : RAW DATA RECORD
Source Data Set ID : RAW DATA RECORD
Software : EDRGEN
Product Data Set ID : VG1/VG2-S-ISS-2-EDR-V2.0
Software 'VIMBUILD'
-------------------
The functions of VIMBUILD include: 1) to receive,
reconstruct, and format high rate telemetry data into
'images' 2) decompress data and fill edited data as required,
and 3) extract and store selected spacecraft and sensor
engineering data from telemetry.
Source Data Set ID : FRAMSINK
Software Name : VIMBUILD
Product Data Set ID : UNPROCESSED DATA RECORD
Software Type : N/A
Software Release Date : 1985-10-01
Node ID : IMAGING
Cognizant Engineer : SUSAN K. LAVOIE
Software Access Description : NOT ACCESSIBLE THROUGH PDS
CATALOG - CONTACT NODE.
Software 'MERGE'
----------------
The MERGE program creates a new Voyager image from all
version of a specified image. This program is part of the
VICAR system (see VICAR).
Source Data Set ID : UNPROCESSED DATA RECORD
Software Name : MERGE
Product Data Set ID : RAW DATA RECORD
Software Type : N/A
Software Release Date : 1989-09-01
Node ID : IMAGING
Cognizant Engineer : SUSAN K. LAVOIE
Software Access Description : NOT ACCESSIBLE THROUGH PDS
CATALOG - CONTACT NODE.
Software 'EDRGEN'
-----------------
The EDRGEN program generates Voyager EDR formatted tapes.
This program is a part of the VICAR system (see VICAR).
Source Data Set ID : RAW DATA RECORD
Software Name : EDRGEN
Product Data Set ID : VG1/VG2-S-ISS-2-EDR-V2.0
Software Type : N/A
Software Release Date : 1989-09-01
Node ID : IMAGING
Cognizant Engineer : SUSAN K. LAVOIE
Software Access Description : NOT ACCESSIBLE THROUGH PDS
CATALOG - CONTACT NODE.
|
DATA_SET_RELEASE_DATE |
1988-05-01T00:00:00.000Z
|
START_TIME |
1980-09-28T12:00:00.000Z
|
STOP_TIME |
1981-08-22T12:00:00.000Z
|
MISSION_NAME |
COMET SL9/JUPITER COLLISION
VOYAGER
|
MISSION_START_DATE |
1993-01-01T12:00:00.000Z
1972-07-01T12:00:00.000Z
|
MISSION_STOP_DATE |
1996-01-01T12:00:00.000Z
N/A (ongoing)
|
TARGET_NAME |
DARK
SATURN
S RINGS
CALYPSO
DIONE
DIONE B
ENCELADUS
EPIMETHEUS
HELENE
HYPERION
IAPETUS
JANUS
MIMAS
PANDORA
PHOEBE
RHEA
ROCK
TELESTO
TETHYS
TITAN
UNKNOWN
|
TARGET_TYPE |
CALIBRATION
PLANET
RING
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
SATELLITE
UNKNOWN
|
INSTRUMENT_HOST_ID |
VG1
VG2
|
INSTRUMENT_NAME |
IMAGING SCIENCE SUBSYSTEM - NARROW ANGLE
IMAGING SCIENCE SUBSYSTEM - NARROW ANGLE
IMAGING SCIENCE SUBSYSTEM - WIDE ANGLE
IMAGING SCIENCE SUBSYSTEM - WIDE ANGLE
|
INSTRUMENT_ID |
ISSN
ISSN
ISSW
ISSW
|
INSTRUMENT_TYPE |
CAMERA
CAMERA
CAMERA
CAMERA
|
NODE_NAME |
Imaging
|
ARCHIVE_STATUS |
ARCHIVED
|
CONFIDENCE_LEVEL_NOTE |
Overview
========
This data set represents a collection of raw images from
Voyager 1 & 2 Saturn encounters beginning with the Observatory
Phase. To make full scientific use of the image collection, it
is necessary to understand and obtain (from the Imaging Node)
the radiometric and geometric properties of the camera system
and perform corrections to the data. Geometry and basic
pointing information is included for all Image Observation
Types including Calibration, Stars and very small Satellites
(or 'Rocks'). Non major planetary bodies, like rocks may have
geometry that refers to the primary planetary bodies (SATURN,
MIMAS, ENCELADUS, TETHYS, DIONE, RHEA, TITAN, HYPERION,
IAPETUS, and PHOEBE).
We recommend obtaining a copy of the 'Software Interface
Specification, ISS PI SEDR Processor, Rev.b, SIS 4-7008-2', an
internal JPL document available from the JPL vellum files, for
reference while using this data set. This document will
clarify some questions which may arise when using the geometry
data, particularly for non primary planetary bodies. For
example; the original predict Supplemental Experiment Data
Records (SEDRs) had a target for each image. Some targets have
been changed as information about that particular image has
been refined. However the geometry still refers to the
original target from the SEDR. We suggest contacting the
Imaging Node for more information, clarification or assistance.
The values for emissions and incidence angles contain errors
and were received that way on the original set of SEDR tapes.
We intend to update these values when the entire set of SEDR
tapes are regenerated.
While using more than one Voyager data set some confusion can
occur due to duplications in the Flight Data System (FDS)
counts (a.k.a. spacecraft clock times). This is due first to
the fact that Voyager 1 and 2 flew concurrently, so there is
inter-spacecraft duplication, and second because of spacecraft
clock resets and rollovers that occurred, causing duplication
within data sets. Users are cautioned therefore, that the FDS
count is not a unique identifier for an image. A unique query
must include the spacecraft ID, the FDS count, and the target.
There are two targets which may cause some confusion; ROCK and
SYSTEM. Most ROCKs have names but some were potential
satellites that never came to fruition or which may be named
sometime in the future. The target SYSTEM indicates a image of
the Saturn System or a section of that which will be used in
conjunction with other sections to create a mosaic.
The target DARK is a dark current image when the camera mode is
in bodark and the exposure is zero.
|
CITATION_DESCRIPTION |
Citation TBD
|
ABSTRACT_TEXT |
This Voyager 1 & 2 Saturn data set is available on CD-ROM.
|
PRODUCER_FULL_NAME |
SUSAN K. LAVOIE
|
SEARCH/ACCESS DATA |
Rings Node Search Tool
Imaging Planetary Image Atlas
Rings Node Interface
Imaging Online Data Volumes (JPL)
Imaging FTP Online Archives (USGS)
Rings Voyager Catalog
|
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