- Email: [email protected]
The Planetary Data System Geosciences Node
Phet.
Pergamon
Spucr Sk, Vol. 44, No, 1, pp. 13-22, 1996 Copyright c 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved 00324633~96 $15.00+0.00
0032-0633(95)00102+Ti
The Planetary Data System Geosciences Node Edward A. Guinness, Raymond E. Arvidson and Susan Slavney Department of Earth and Planetary MO 63130. U.S.A.
Sciences, McDonnell
Center for the Space Sciences, Washington
University,
St. Louis.
Received 1 December 1994 ; accepted 30 April 1995
Abstract. The purpose of the Planetary Data System Geosciences Node is to archive and distribute planetary geosciences datasets relevant to the surfaces and interiors of the terrestrial planets and moons. This objective is accomplished through the following efforts. The Node works with plam%arymissions to help ensure ‘ences discipline are that data of relevance to the The Node restores properly dommmted and and publishes sel@ed eence datasets from past missions on CD-RoN.fsur distibutiaa to the planetary science community. Data archived at the Node are distributed on CD-ROM, tignetic tape, CD-WO, or by electronic @an&r over fhe Internet. The Geesciences Node provides information and expert assist-
CurrM archives
Mercury, Mars, Earth, and ware to analyze the data. and to order selected datasets. Access s c-a&logsand on-line datasets is available via the Internet using a remote login or via the World Wide Web (WWW). Introduction The Geosciences Node is one of the discipline nodes of the Planetary Data System (PDS) (Lee, 1991 ; Arvidson
Correspondent
to
: E. A. Guinness
and Dueck, 1994). The Node consists of a distributed group of planetary scientists and computer and information specialists. It is organized with a lead node and a series of discipline-specific subnodes. The purpose of the Geosciences Node is to archive and distribute datasets. documentation, and associated software for observations covering the surfaces and interiors of the terrestrial planets and moons of our solar system. The Node focuses on the production of documented planetary data archives and software, along with the distribution of these archives to the science community. Except for imaging data, both raw and derived datasets are under the Node’s purview. The Node archives derived image datasets and works with the PDS Image Node to ensure that raw image archives are available. Data distribution occurs through such media as compact disks, and tapes, and through on-line services that use the Internet, World Wide Web (WWW), and distributed database management technologies. The Node also works with personnel from planetary missions to ensure that PDS-compatible archives of geoscience datasets are generated by the mission. The Geosciences Node provides a number of services in addition to publishing and distributing data. The Node maintains on-line catalogs of its data holdings. The catalogs assist the research community in navigating through the available datasets and accept requests for data. The Node also serves the scientific community by providing advice about data and software archived at the Node. To the extent possible, Node personnel interact with educators and the public by distributing relevant data and answering questions about our solar system. The Node serves as the PDS interface to NASA’s Regional Planetary Image Facilities. Finally. because of the expertise and interest of its personnel. the Node has taken a leading role within the PDS in interacting with our Russian colleagues on PDS-related issues and working with our European colleagues on Venus and Mars data. In this paper the PDS Geosciences Node organization is described, along with the functions of each of the Node’s parts. The data archives and software produced by the Node are discussed, as are archiving plans for the next
E. A. Guinness et al. : The Planetary Data System Geosciences Node
14
PDS GEOSCIENCES NODE MANAGEMENT STRUCTURE
PDS Central Node TPL
Image Node USGS
Mars 96 Camera Data Node Institute of Planetology
Fig. 1. Structure
of the Geosciences Node. Groups in the shaded zone include the lead node and subnodes. Connections to the PDS Central Node and Image Node are also shown to indicate close cooperation with these groups. RPIFs are shown because they represent the Node advisory group several years. A summary of the services available the Geosciences Node to the planetary research munity is also provided.
from com-
Node organization The Geosciences Node is distributed among a lead node and four subnodes (Fig. 1). The subnodes are focused on specific types of data relevant to a subdiscipline of geosciences, whereas the lead node provides a broader view across the entire geosciences discipline. The four subnodes deal with microwave, geophysical, thermal emission, and radio science data. In addition to the lead node and subnodes, there are agreements for Node personnel to work with European and Russian institutions to produce PDS-compatible archives. The two European groups shown in Fig. 1 are considered data nodes, meaning that they are associated with the Geosciences Node for a finite period of time to produce a specific set of data archives. The German group at Deutsche Forschungsanstalt fiir Luft- und Raumfahrt (DLR) will produce a data archive from the camera system on the Russian Mars-96 Orbiter mission. The Austrian group at Graz University of Technology will produce derived datasets
from the existing Magellan data archives. The relationship with the Russian group in Fig. 1 is to pursue common goals of data archiving of geoscience data in support of cooperative missions with the U.S. and Russia and to assist the Russians in developing a prototype Russian PDS. The Geosciences Node also has a close connection with the PDS Image Node, as shown in Fig. 1, since image data is of direct relevance to the geosciences discipline. An important function of the lead node, housed at Washington University, is to provide overall management of the Node. The lead node is also responsible for development and operation of catalogs to support navigation through and ordering of data held by the Node. Interfacing with planetary missions, the rest of PDS. and our European and Russian colleagues is done largely by the lead node. Both the lead node and the subnodes are actively involved in data archive production, either by restoring data from past missions or working with ongoing missions. The lead node also operates a support office for Magellan data products, where users can ask for information about the availability of data products and about what software exists to work with the data products. The lead node maintains a set of hardware to support the Node’s work. This equipment is shown schematically in Fig. 2. The database server supports the Node catalogs,
E. A. Guinness
et al. : The Planetary
Data System Geosciences
Node
PDS GEOSCIENCES NODE COMPUTING RESOURCES
CUSTOM PROCESSING INTERNET Fig. 2. Schematic diagram that shows the computing resources at the lead node of the Geosciences Node. The schematic shows the catalog host computer, CD-W0 writer, and CD jukeboxes
which store information about data holdings at the lead node and selected datasets managed by the subnodes. There are also several devices available at the lead node for the production of CD write-once (CD-WO) volumes. Nearly 200 Gbytes of data can be stored near on-line in a set of 3 CD jukeboxes, with each jukebox holding 100 CD volumes. Finally, the lead node has additional computing hardware and software that is used to support a limited amount of specialized data processing for users. The four subnodes within the Geosciences Node focus their work on specific types of geoscience data. The microwave subnode at MIT is involved with archiving planetary radar data, microwave radiometry data, and altimetry data derived from radar and laser systems. These data are available for Venus, Mars, and the Earth’s moon. The geophysics subnode at Washington University is involved
Table 1. Datasets
archived
at the Geosciences
in archiving line-of-sight (LOS) gravitational acceleration data for Mars, Venus, and the Moon. This subnode also generates and archives maps of gravity anomalies and spherical harmonics of gravity and topography data. Seismic data from the Moon are under the purview of the geophysics subnode. The thermal data subnode at Arizona State University archives thermal infrared data collected by a wide range of spaceborne instruments. These thermal observations are available for Mars, the Moon, and the satellites of the outer planets. The radio science subnode at Stanford University works on archiving bistatic radar observations, information on planetary surface characteristics derived from altimetry, radiometry, and SAR data, and radio occultation data to determine planetary radii. Such observations are available for Mars. Venus, and the Moon. Each subnode is actively developing software tools that enable users to access and navigate through the datasets housed at the subnodes. Users access the subnodes through Internet connections and WWW hypertext interfaces. Each discipline node within the PDS has an advisory council. As shown in Fig. 1, the Geosciences Node advisory group is NASA’s Regional Planetary Image Facility (RPIF) Director’s Council. The reason is that the RPIFs are primary users of geoscience data products. Thus, they can provide advice that is of an expert nature and userbased. Through the Geosciences Node the RPIFs can also make the PDS aware of their needs.
Node data and software archives During the past five years, the Geosciences Node has produced and distributed several important data archives. These archives include datasets restored from past missions, several datasets that were previously maintained
Node
Dataset Mugellun Basic Image Data Record
I5
(BIDR)
Planets
Description
Venus
SAR images for data acquired along individual orbits Mosaicked BIDR products in image format Altimetry and radiometry data acquired along orbital tracks Global image maps of altimetry. emissivity, radar reflectivity, and slopes Spacecraft accelerations due to Venus gravity along the line of sight between the spacecraft and Earth Raw altimeter data
Mugellun Mosaicked Image Data Record (MIDR) Magcllun Altimetry. Radiometry Composite Data Record (ARCDR) Mugellun Global Data Record (GxDR)
Venus Venus
Line-of-Sight Acceleration Profile Data (LOSAPDR) Mugellun Altimeter Experiment Data Record
Venus
Magellun
Venus
Record
Venus
( ALT-EDR)
Pre-Magellun
Data Collection
Geologic Remote Sensing Field Experiment (GRSFE) Data Collection c’iking Orbiter Visual Imaging Experiment Data Record (EDR) I’ikin,g Orbiter Infrared Thermal Mapper (IRTM)
Mercury. Venus, Earth. Moon, and Mars Earth
Mars Mars
Altimetry, radar images, and gravity datasets comparison to Magellun data
for
Airborne visible through microwave wavelength datasets and ground-based data for targets in southwestern U.S. Visible wavelength images of the surface, atmosphere, and moons Thermal infrared radiometer and broad-band albedo measurements of the surface and atmosphere
E.
16
A. Guinness et al. The Planetary Data System Geosciences Node
Archive volume productionby product
Archive volume distributionby product
500
!!!!!i %EN
400
B
Vikinn I EDRs
8 $ 300 % _g 200
m
MGN LOSAPDRs
2
0
1991
1992
1993
1994
Year
2000
Fig. 3. Summary of archives produced by the Geosciences Node
or produced by a planetary mission and now maintained by the Node. Archive volumes are primarily CD-WOs and CD-ROMs. See text for definition of acronyms
0
Archive volume distribution by medii
by individual investigators, and several terrestrial datasets of relevance to planetary geosciences study. The Node has also worked with the Magellan mission on the production of Magellan data product archives that have been delivered to the Geosciences Node for long-term maintenance. The current archives within the Geosciences Node are summarized in Table 1 and the sizes of these archives are shown in Fig. 3. Each archive was designed using the PDS standards that were current at the time of archive production. Each archive also went through a peer review before the archive was completed and accepted by the Node. The reviews were conducted by scientists knowledgeable of the data. The Geosciences Node archives are stored on a combination of CD-ROM and CD-W0 media. Data on CDROM has been widely distributed to the science community, whereas data on CD-W0 is electronically distributed to researchers when requested. Figure 4 shows a summary of the volume of data distributed by the Node. In addition to the production of data archives, the Node has produced several software packages for use with these data archives, as listed in Table 2. The lead node, working with the microwave and geophysics subnodes, generated a CD-ROM with 15 radar, altimetry, and gravity datasets, including extensive Earthbased radar observations of the Moon and the inner planets (Arvidson et a/., 1990). The intent of this dataset collection was to provide a set of relevant radar and gravity data for comparison to Magellan data. Thus, this CDROM is referred to as the pre-Magellan CD-ROM. The volume contains image data and data tables from the Pioneer-Venus Orbiter and Viking Orbiter missions, the Goldstone, Arecibo, and Haystack Earth-based radar observatories, and the NASA AIRSAR airborne imaging radar system. Several hundred copies of the pre-Magellan CD-ROM have been distributed to date (Fig. 4). A set of nine CD-ROMs was produced by the lead node from the Geologic Remote Sensing Field Experiment (GRSFE). This experiment was designed to acquire visible through microwave wavelength datasets from NASA aircraft over targets in the southwestern United States that have relevance as planetary analogs (Arvidson et al., 1991). During the acquisition of the airborne data, a suite
Fig. 4. Summary of the amount of data distributed by the Geosciences Node. The top graph shows the values based on media type. Values for Magellan datasets include only data distributed by the Node after release of volumes by the Magellan Project. Note in the bottom figure the dominance of CD-ROMs and the more recent emergence of data distribution on CD-W0 and by electronic means. See text for definition of acronyms
of ground-based measurements were also made to provide calibration and ground-truth for the airborne data. These ground-based data are included in the GRSFE CD-ROM archive. The intent of GRSFE was to develop comprehensive datasets to test quantitative models for estimating surface property information of relevance to the inner planets and to facilitate characterization of surfaces across different wavelength intervals. The GRSFE archive has been widely distributed to scientists interested in both planetary and Earth remote sensing studies. The lead node and the microwave, geophysics, and radio science subnodes participated heavily in the generation, validation, archiving, and distribution of Magellan datasets (Saunders et al., 1990). The close work with the MageZian mission was facilitated by the fact that several members of the Geosciences Node were also members of the Magellan science team. Specifically, they were involved
in design and validation of radar mosaic (MIDR), altimetry and radiometry (ARCDR), and global map (GxDR) data product archives on CD-ROMs. The MIDR, ARCDR, and GxDR archives are located on sets of 126, 19, and 2 CD-ROMs, respectively. The lead node continues to distribute the MIDR, ARCDR, and GxDR
I. A. Guinness
et ~1. : The Planetary
‘able 2. Software oftware
at the Geosciences
Data System Geosciences
Node
Node
name
Description
rnage Retrieval and Processing ‘ES database iravity Analysis Software 4GMDQE pfagrllun HyperMap
17
Software
Package
(IRPS)
(GASP)
noducts. The lead node is the primary archive for the ull-resolution basic image data records (F-BIDRs), radar mages on over 5200 9-track tapes. Data from these tapes Ire being systematically validated and converted to CDNOs at the lead node, with advice from the microwave md radio science subnodes. When complete, the F-BIDR nchive will consist of approximately 550 CD-WOs with a otal data volume of about 300 Gbytes. At the microwave ubnode, compressed BIDRs (C-BIDRs) and altimetry {xperiment Data Records (ALT-EDRs) are being sysematically validated and transferred to CD-WOs, to ,esult in archive collections of 124 and 71 volumes, respecively. Magelh gravity products were validated at the geophysics subnode. and a CD-W0 was generated for iata and documentation from mapping cycle 4. The geo)hysics subnode is also continuing work with Magellan napping cycles 5 and 6 gravity products. The lead node prepared data and documentation for m archive of 32 CD-ROMs containing Viking Orbiter 1 VOl) Visual Imaging Subsystem Experiment Data Rec)rd (EDR) images as a data node to the PDS Image Node Guinness et a/.. 1990). Data for the Viking Orbiter 2 VO2) images were prepared by the PDS Image Node. A otal of 50,500 images are included in the VOl and V02 mage archive on a collection of 46 CD-ROMs. The image lata are stored in a compressed format using a Huffman Trst-difference compression algorithm that is lossless. To ‘acilitate rapid browsing of the image collection, subsampled versions of each image are included. The archive also contains software for decompressing the EDR Images. Since the Viking Orbiter image archive consists of raw EDR image data, it is currently maintained by the PDS Image Node. The thermal subnode is in the process of restoring the Viking Orbiter Infrared Thermal Mapper (IRTM) database. This dataset consists of about 600 Mbytes of thermal infrared and broad-band albedo measurements of the martian surface and atmosphere. After restoration peer review of the 1RTM archive. it will be distributed along with software to access and analyze the data on a set of two CD-ROMs. The microwave subnode has been active in working with individuals from the Russian Institute of Radiotechnology and Electronics and the Moscow Power Institute to archive Russian Venera 15 and 16 data on several CD-WOs. This dataset will include radar and altimetry observations of the surface of Venus. The PDS Educational CD-ROM, called Welcome to the Planets. has been developed as a joint effort between the Geosciences Node as the science lead and the PDS Central Node as the technology coordinators and pro-
Includes image processing software developed by Image Node. Used to make specialized products Access to spectral datasets Modeling and inversions of gravity data Display Magellan ARCDR, GxDR, and MIDR datasets Quick-look tool for searching and accessing Mugdan MIDR and GxDR datasets on a Macintosh
ducers of the disk. The CD-ROM contains approximately 200 planetary images and diagrams of spacecraft, along with information about the images and the planets. It is designed for educational use at the high school and collegiate levels. The Geosciences Node has developed a number of software packages for distribution to the community. The lead node developed and now maintains the Image Retrieval and Processing System (IRPS), a combination of an on-line catalog for image data and image processing software for analysis of the data. The catalog includes detailed information about Viking Orbiter and Voyager images, as well as general information about other missions. The image processing software is based on the PICS system developed by the USGS in Flagstaff. IRPS is used by the RPIFs and others in the planetary science community.The microwave subnode has developed the Magellan HyperMap program for the Macintosh. a quicklook tool for accessing and displaying MIDR and GxDR products from the Magellan CD-ROMs, along with the Magellan Experimenters’ Notepad (Fig. 5). HyperMap has been distributed to the RPIFs and other PDS users. The geophysics subnode has participated in the development of gravity data analysis software known as GASP for use with Magellan Line-of-Sight Acceleration Profile Data Record (LOSAPDR) products. GASP does both forward modeling of LOS acceleration data and inversions to extract information about subsurface properties and dynamics. The thermal subnode has developed database management software for satellite-derived and laboratory multispectral data. Designed for use with data from the Mars Global SurzleJ,or Thermal Emission Spectrometer (TES) instrument, the software is called the TES Database. but can be used for any spectral data, including the Viking Orbiter IRTM archives. It is designed to use PDS-labeled data products.
Node services The Geosciences Node is involved in a number of activities to assist its users besides data archiving and distribution. These services include developing and maintaining data product catalogs, working with PDS as a whole to develop archiving standards, and interacting with educators and the public. The Node has electronic catalogs that allows users to conduct searches and place orders for Node archives, including datasets, documentation, and software. The catalogs use relational database management
E. A. Guinness
CD-ROM Uolume: Starting Orbit: Ending Orbit: Center Longitude: Center Latitude: Incidence Angle: Illuminated from:
et al. : The Planetary
MG-0048 1674 2218 299.393674 74.865415 20.1’ - 24.7” left
Feature
Data System Geosciences
Node
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To aid in north pole location studies, the swath width widened from 20 km to 35 km from 90’N to 80’N. (MCR 902)
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~~There wea a clock miseligrUJB%Itbetween the spacecraft and the ground arhich nsultid in an apparent mis-illumina tion of the data swath for e.ll orbita in this upload. Although some corrections could be made during processing, a decrease in image data quality occurs along the swath edges. Altimetry and radiometry products were unaffected.
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Fig. 5. Example illustrating the Mngellan HyperMap capabilities. Top screen shows information for one MIDR product. including the location of features within the mosaic. Bottom screen shows uplink and downlink comments and a summary of commands along the orbital track for orbits 376403
software and the PDS data dictionary. All data archives under the Geosciences Node purview will be included in the Node catalogs. Currently, the catalogs have information about Magellan radar, altimetry, and gravity data products and Viking Orbiter and Voyager images. The lead node is also developing a catalog of Clementine data
products of the Moon. Working with the Image Node, the catalog will include image, altimetry, and gravity data products. The operation of the catalog will probably be split between the Geosciences lead node and image Node, using distributed database capabilities. Scientists who are registered users of the PDS can access
E. A. Guinness
et nl. : The Planetary
Data System Geosciences
the Geosciences Node catalogs through the PDS Central Node catalog system. Access is via the Internet using a remote login from the Central Node to the Geosciences Node. A more convenient and more widely accessible method of electronically connecting to the Geosciences Node on-line services is via the WWW using a browser program such as Mosaic. This method of access is available to anybody with Internet access and WWW browser software. The URL (Uniform Resource Locator) for the Geosciences lead node is “http://wwwpds.wustl.edu/“. The information available through the lead node WWW interface includes information on available datasets at the lead node and how to obtain them, access to the Node’s catalog system, access to geosciences subnode WWW interfaces, and a list of personnel at the lead node and how to contact them. From the Geosciences Node WWW interface, users can also connect to the PDS Central Node WWW interface. which provides links to all the other PDS discipline nodes. Users can search the Node catalogs for data products through categories such as product name and type, time of acquisition, location on a planet. and geographic feature name. Figure 6 shows schematically how the Node catalogs can be searched using the Magellan catalog as an example. Figure 7 shows an example screen from the user interface to the Magellan catalog. Users can submit orders for data products found in the catalogs. Data ordered through the catalogs are distributed either by mailing copies of CD-ROMs, by copying data to tape or CD-WO, and by electronic transfer over the Internet. With more users gaining access to the Internet, the Node is attempting to encourage greater use of electronic data transfer. For example, a large portion of the Magellan F-BIDR dataset is on-line in a set of CD jukeboxes that hold 300 CD volumes. Data in these jukeboxes can be ordered through the Magellarl catalog and then electronically transferred to the user. Figure 8 shows schematically how a user would work with the Node catalog system to electronically transfer data from the on-line database back to his local computer. Node personnel have been active in the development of PDS standards that are important to geosciences datasets (e.g. map projections, coordinate systems, and label formats) and in the development of processes related to generation and validation of archives. Such standards and processes are valuable in ensuring that the PDS produces high-quality, well-documented data archives for the science community. The Node has also been very active in working with mission personnel in Europe and Russia on issues related to archive production. Although not formally part of the PDS charter. education and public outreach activities using PDS datasets are an important component of what the PDS is doing. Thus, the Geosciences Node has been involved in outreach activities that include operating WWW servers at the lead node and each of the subnodes. The microwave subnode server provides access to NASA archives and allows browsing of Magellan MIDR images. The thermal subnode provides information of the current status of planetary missions. The lead node has been working with The Planetary Society on the Marslink program, which produces classroom exercises about Mars science. The
Node
19
HOW TO NAVIGATE THE MAGELLAN CATALOG
BY
Feature
BY
Time
Look for orbiis covering time range
I
Orbit Range
Look for orbits or maps covering lat-ion boundaries I
%it Map Product ID
BY
Name
Media, Volume ID, File name
Fig. 6. Flow diagram illustrating the Mqrlkm catalog capabilities. Major search categories are shown on the left and include searching by feature name. by time. by location, by orbit. and by product name. Searches can start at any level. The arrows are intended to show connections between the components of the catalog and the flow of the search to find a specific set of products. Data products found by such searches can be ordered through the catalog. Orders are filled by CD-ROM, CD-WO. and a growing amount of electronic data transfer using the Internet
Marslink materials are available on-line through the lead node WWW server. In addition. the Node makes selected PDS datasets available to educators and the public.
Node data archiving and software plans The Geosciences Node plans to continue to be very active in archiving datasets over the next several years. The new archives will include data restored from past missions such as Viking, Pioneer- Venus, and Apollo, data from recently complete missions such as Clmentinr and Magellan, and data from missions such as Mars Global Surrq~or and the Discovery class Lunar Prospector mission that should return data over the next few years. The Node expects to be active in interfacing with on-going missions on issues of archive production. The Node will also be working with its international partners to make geosciences data from international missions available through the PDS. Table 3 lists a summary of datasets that the Geosciences Node plans to archive over the next five years. In addition,
E. A. Guinness
et al. : The Planetary
Data System Geosciences Node
Fig. 7. An example of a search screen from the Magellun catalog. This screen is used to locate geographic features on Venus. Features can be found by specifying name. type. or area of the planet. The information returned by the search includes the feature location, its size, and the origin of the name. The catalog can be directed to map to the data products that cover the features located by the search
ELECTRONIC ORDER AND DELIVERY Quenf
FTP
Read Data from CD Jukebox
Fig. 8. Flow diagram illustrating the Geosciences Node electronic order and data distribution system. This mechanism is used for data archived on CD-W0 media and stored on-line in the Node’s CD jukeboxes. Users query the Node catalog to select data and submit an order for that data. The system automatically transfers the data from CD-W0 in a jukebox to a staging area on disk. Moving products from CD to hard disk is necessary in order to handle multiple data orders at one time. After products are staged, an electronic mail message is sent to the user to inform him that the data are ready for transfer. The user is sent instructions on how to transfer the data using ftp. Finally, the user issues commands to transfer the data back to his local computer
software tools will be developed as needed for use with datasets archived at the Node. Even though the Magellan mission has ended operations, there are several Magelfan datasets that still have to be archived and cataloged so that they c’dn be made available for distribution. These datasets include the Magellan SCVDR dataset (vector representations of scattering properties of surface), global maps of surface properties generated from the SCVDRs, Magellan bi-static radar observations, LOS gravity products from the later part of the mission, and spherical harmonic expansion models of the gravity and topography fields. The datasets will be initially archived on CD-W0 and distributed electronically through the Node catalog. If a large number of requests for the data are made, some of the data will be transferred to CD-ROM for wide distribution. There are several additional Venus datasets from past missions that the Node plans to archive within the PDS. The Pioneer- Venus altimetry and emissivity datasets. including the raw data, and the gravity datasets will be restored and archived. The archiving of Venera 15 and 16 altimetry, radiometry, and radar data will be completed, with help from our Russian colleagues. Earth-based radar observations of Venus are an important group of datasets. The Node will also be working to archive these observations, primarily Arecibo, Goldstone, and VLA data. Archiving of data from the moon will concentrate on digital data from the Clementine, Apollo, and Lurlar Prospector missions. The Node will continue to work closely with the Image Node on Clementine image archives. The Geosciences Node will archive Clementine derived image datasets (e.g. calibrated multispectral image mosaics), altimetry data, and gravity datasets. Ciementk bi-static
E. A. Guinness
et (I/. : The Planetary
Table 3. Geosciences
Node datasets
Data System Geosciences
Node
71
to be archived
Dataset
Planets
Description
.hlugellun SCV DR Mugellun Bi-static Radar
Venus Venus
l’c~rtz 15. I6 Data P ior~rr- I hu.s Radar Data Pioneer- I’errus Gravity Data Ckmenrinr Altimetry Data Clementirw and .4pollo Gravity
Venus Venus Venus Moon Moon
Surface characteristics derived from SAR and altimetry data Microwave transmissions from spacecraft reflected from planet surface and received on Earth Radar, altimetry, and radiometry data Radar backscatter data Line-of-sight accelerations due to gravity as orbital tracks Orbital tracks and gridded map products Line-of-sight accelerations due to gravity as orbital tracks and gridded map products Microwave transmissions from spacecraft reflected from planet surface and received on Earth Multispectral image mosaics Gamma Ray, Neutron Spectrometer. Alpha Particle. and Radio Science datasets Experiment Data Record (EDR) images and mosaics Microwave transmissions from spacecraft reflected from planet surface and received on Earth Infrared radiometry and spectroscopy Orbital tracks and gridded map products Thermal infrared emission spectra Line-of-sight accelerations due to gravity as orbital tracks and gridded map products Mosaicked image products
Cker~erzrinc, and .4170//o Bi-static
Data Radar
Moon
C(ementirw Derived Image Data Lurlur Pro.~pi~tor
Moon Moon
c’ikiri~qLmder Images Viking Bi-static Radar
Mars Mars
Marirwr 6. 7. and 9 Infrared Data MGS Laser Altimeter (MOLA) Data MGS Thermal Emission Spectrometer MGS Gravity Data
Mars Mars Mars Mars
MGS Derived
Image Data
(TES) Data
Mars
radar data will be archived. Many of the Clementirle archives will be placed on CD-WOs. made available online through our catalog, and transferred to CD-ROMs if widespread distribution is need. The Geosciences Node will have an active role in working with the Lunar Prospector mission to archive data products from the Gamma Ray, Neutron. Alpha Particle, and Radio Science experiments. Finally, the Node will archive Apollo 17 Infrared Scanning Radiometer (ISR) data, along with Apollo bistatic radar and gravity data. For Mars datasets, the Node will conduct several efforts in archiving past mission data and in planning for several Mars missions that should return data in a few years. The Node will restore and archive existing thermal radiometer and spectrometer datasets for Mars, specifically working on Mtrrirwr 6 and 7 IRS and Mariner 9 IRIS data. The Viking Lander Camera Experiment Data Records will also be archived with help from the Image Node. Further, the I=ikiq Ohitc~r bi-static radar and gravity observations will be archived. As with Venus. the Node will archive Earth-based radar observations of Mars, including Arecibo, Goldstone. and VLA datasets. Both the spacecraft mission and Earth-based data will be very important datasets for use in planning and in analyzing data from upcoming Mars missions. The Geosciences Node expects to be heavily involved in the archiving of Mars Global Suweyor (MGS) data. Specifically. the TES (Thermal Emission Spectrometer) data will be archived and released with relevant software as on-line products and as CD-ROMs. The Node expects to archive MOLA (Laser Altimeter) observations in much the same way. Derived image products (i.e. calibrated image mosaics) will be archived and cataloged by the Geosciences Node. In addition, the Node will archive MGS gravity data. including line-of-sight Doppler accel-
erations and spherical harmonic expansions. Finally, the Geosciences Node expects to be involved in archiving Mars Pathfinder data. The whole Mars Pathfinder archive could be published on several CD-ROMs. The Geosciences Node is a primary PDS interface to the growing activity related to international access to Mars datasets. Specifically, working with our colleagues in Germany and Russia. the Node expects to work on a distributed catalog called the International Mars Database (IMDB). A user would be able to conduct searches for Mars data from several sites around the world and not need to know that the catalog is distributed. Some of the datasets from European and Russian missions that may be part of the IMDB include several Pkohos mission datasets such as near-infrared spectroscopy and thermal infrared radiometry. and Mum-96 datasets such as imaging. visible and near-infrared spectroscopy, and thermal infrared radiometry. In addition, all the Mars datasets housed at the Geosciences Node would be included. Orders could be placed at any site and filled by the site that archives the data. The IMDB will come to fruition when Mcrrs Ghhol SurreJ,or and Mars-96 data become available. The Geosciences Node has found that archives are most useful if they are accompanied by software packages to process and analyze the data. Thus, a number of packages will be developed over the next five years. For example, a significant effort will be the TES database software to display and analyze Mars spectral datasets. culminating in the ability to extract spectra from the complex TES archives that will be returned by the MGS mission. In addition, the Magellarz stereo toolkit software. which was developed for Magellan investigators. will be updated and made available to NASA-sponsored researchers. It will have the added capability to handle F-BIDRs in rangeDoppler coordinates.
22 Summary
The philosophy of the Geosciences Node and the emphasis of the work it does can be summarized by the following points. (1) The Node is focused on archive production and distribution of planetary geosciences data from spacecraft missions and some Earth-based observations. Archives are generated on CD-WOs and made available through the Node’s on-line catalog. Popular datasets will migrate to CD-ROMs for distribution. Some datasets will be placed on CD-ROMs directly if wide distribution is needed. The Node maintains the expertise about its datasets in order to assist researchers in the use of the data. (2) The Node attempts to establish close working relationships with missions. Working with missions while archives are being designed and produced will help ensure that high quality, well documented archives are produced. One way that the Node has been able to develop such relationships with missions is by having Node personnel involved in both the missions and the PDS. (3) The use of datasets is enhanced by the availability of software tools. The Geosciences Node develops appropriate software for access and analysis of certain types of datasets such as spectral and gravity datasets. (4) The Node develops and maintains on-line catalogs of datasets within the Node. The catalogs contain information about individual data products within a dataset. The catalogs are intended to assist users in moving through large datasets and in selecting subsets of data. (5) The Geosciences Node is active in developing international cooperation to provide access for researchers to international datasets. The Node has placed particular emphasis on international datasets for Mars and is work-
E. A. Guinness et al. : The Planetary Data System Geosciences Node ing to create an international Mars Database in conjunction with European and Russian colleagues. (6) Public and educational outreach is an important aspect of the Geosciences Node efforts. The Node
attempts to provide selected data products to the public and educators to keep them aware of recent advances in the field of planetary geosciences. Acknowledgements. The authors are supported by JPL Contract 958756 to Washington University for PDS Geosciences Node
tasks. Thanks to an anonymous thoughtful review of this paper.
reviewer for providing
a
References Arvidson, R. E. and Dueck, S. L., The Planetary Data System. Remote Sensing Rev. 9,255-269, 1994. Arvidson R., Guinness, E., Slavney, S., Acevedo, D., Hyon, J. and Martin, M., Archive of Pre-Magellan Radar and Gravity
Data, CD-ROM Vol. USA_NASA_PDS_MG_lOOl, NASA Planetary Data System, JPL, Pasadena, California, 1990. Arvidson, R. E., Dale-Bannister, M. A., Guinness, E. A., Slavney, S. H. and Stein, T. C., Archive of Geologic Remote Sensing
Field Experiment Data-Release 1.O,CD-ROM Vol. USANASA_PDS_GROOOl, NASA Planetary Data System, JPL, Pasadena, California, 1991. Guinness, E. A., Slavney, S., Eliason, E., Martin, M. and Hyon, J., Archive of Images from NASA’s Viking Orbiter 1 and 2 Missions, CD-ROM Vol. USA_NASA_PDS-VO-100 I, NASA Planetary Data System, JPL. Pasadena, California, 1990. Lee, S., The Planetary Data System, Rev. of Geophysics, April Supplement, U.S. National Report to International Union of Geodesy and Geophysics 1987-1990, pp. 338-341. 1991. Saunders, R. S., Pettengill, G. H., Arvidson, R. E., Sjogren, W. L., Johnson, W. T. K. and Pieri, L., The Magellan Venus Radar Mapping Mission. J. Geophys. Res. 95, 833998355,
1990.
Pergamon
Spucr Sk, Vol. 44, No, 1, pp. 13-22, 1996 Copyright c 1996 Elsevier Science Ltd Printed in Great Britain. All rights reserved 00324633~96 $15.00+0.00
0032-0633(95)00102+Ti
The Planetary Data System Geosciences Node Edward A. Guinness, Raymond E. Arvidson and Susan Slavney Department of Earth and Planetary MO 63130. U.S.A.
Sciences, McDonnell
Center for the Space Sciences, Washington
University,
St. Louis.
Received 1 December 1994 ; accepted 30 April 1995
Abstract. The purpose of the Planetary Data System Geosciences Node is to archive and distribute planetary geosciences datasets relevant to the surfaces and interiors of the terrestrial planets and moons. This objective is accomplished through the following efforts. The Node works with plam%arymissions to help ensure ‘ences discipline are that data of relevance to the The Node restores properly dommmted and and publishes sel@ed eence datasets from past missions on CD-RoN.fsur distibutiaa to the planetary science community. Data archived at the Node are distributed on CD-ROM, tignetic tape, CD-WO, or by electronic @an&r over fhe Internet. The Geesciences Node provides information and expert assist-
CurrM archives
Mercury, Mars, Earth, and ware to analyze the data. and to order selected datasets. Access s c-a&logsand on-line datasets is available via the Internet using a remote login or via the World Wide Web (WWW). Introduction The Geosciences Node is one of the discipline nodes of the Planetary Data System (PDS) (Lee, 1991 ; Arvidson
Correspondent
to
: E. A. Guinness
and Dueck, 1994). The Node consists of a distributed group of planetary scientists and computer and information specialists. It is organized with a lead node and a series of discipline-specific subnodes. The purpose of the Geosciences Node is to archive and distribute datasets. documentation, and associated software for observations covering the surfaces and interiors of the terrestrial planets and moons of our solar system. The Node focuses on the production of documented planetary data archives and software, along with the distribution of these archives to the science community. Except for imaging data, both raw and derived datasets are under the Node’s purview. The Node archives derived image datasets and works with the PDS Image Node to ensure that raw image archives are available. Data distribution occurs through such media as compact disks, and tapes, and through on-line services that use the Internet, World Wide Web (WWW), and distributed database management technologies. The Node also works with personnel from planetary missions to ensure that PDS-compatible archives of geoscience datasets are generated by the mission. The Geosciences Node provides a number of services in addition to publishing and distributing data. The Node maintains on-line catalogs of its data holdings. The catalogs assist the research community in navigating through the available datasets and accept requests for data. The Node also serves the scientific community by providing advice about data and software archived at the Node. To the extent possible, Node personnel interact with educators and the public by distributing relevant data and answering questions about our solar system. The Node serves as the PDS interface to NASA’s Regional Planetary Image Facilities. Finally. because of the expertise and interest of its personnel. the Node has taken a leading role within the PDS in interacting with our Russian colleagues on PDS-related issues and working with our European colleagues on Venus and Mars data. In this paper the PDS Geosciences Node organization is described, along with the functions of each of the Node’s parts. The data archives and software produced by the Node are discussed, as are archiving plans for the next
E. A. Guinness et al. : The Planetary Data System Geosciences Node
14
PDS GEOSCIENCES NODE MANAGEMENT STRUCTURE
PDS Central Node TPL
Image Node USGS
Mars 96 Camera Data Node Institute of Planetology
Fig. 1. Structure
of the Geosciences Node. Groups in the shaded zone include the lead node and subnodes. Connections to the PDS Central Node and Image Node are also shown to indicate close cooperation with these groups. RPIFs are shown because they represent the Node advisory group several years. A summary of the services available the Geosciences Node to the planetary research munity is also provided.
from com-
Node organization The Geosciences Node is distributed among a lead node and four subnodes (Fig. 1). The subnodes are focused on specific types of data relevant to a subdiscipline of geosciences, whereas the lead node provides a broader view across the entire geosciences discipline. The four subnodes deal with microwave, geophysical, thermal emission, and radio science data. In addition to the lead node and subnodes, there are agreements for Node personnel to work with European and Russian institutions to produce PDS-compatible archives. The two European groups shown in Fig. 1 are considered data nodes, meaning that they are associated with the Geosciences Node for a finite period of time to produce a specific set of data archives. The German group at Deutsche Forschungsanstalt fiir Luft- und Raumfahrt (DLR) will produce a data archive from the camera system on the Russian Mars-96 Orbiter mission. The Austrian group at Graz University of Technology will produce derived datasets
from the existing Magellan data archives. The relationship with the Russian group in Fig. 1 is to pursue common goals of data archiving of geoscience data in support of cooperative missions with the U.S. and Russia and to assist the Russians in developing a prototype Russian PDS. The Geosciences Node also has a close connection with the PDS Image Node, as shown in Fig. 1, since image data is of direct relevance to the geosciences discipline. An important function of the lead node, housed at Washington University, is to provide overall management of the Node. The lead node is also responsible for development and operation of catalogs to support navigation through and ordering of data held by the Node. Interfacing with planetary missions, the rest of PDS. and our European and Russian colleagues is done largely by the lead node. Both the lead node and the subnodes are actively involved in data archive production, either by restoring data from past missions or working with ongoing missions. The lead node also operates a support office for Magellan data products, where users can ask for information about the availability of data products and about what software exists to work with the data products. The lead node maintains a set of hardware to support the Node’s work. This equipment is shown schematically in Fig. 2. The database server supports the Node catalogs,
E. A. Guinness
et al. : The Planetary
Data System Geosciences
Node
PDS GEOSCIENCES NODE COMPUTING RESOURCES
CUSTOM PROCESSING INTERNET Fig. 2. Schematic diagram that shows the computing resources at the lead node of the Geosciences Node. The schematic shows the catalog host computer, CD-W0 writer, and CD jukeboxes
which store information about data holdings at the lead node and selected datasets managed by the subnodes. There are also several devices available at the lead node for the production of CD write-once (CD-WO) volumes. Nearly 200 Gbytes of data can be stored near on-line in a set of 3 CD jukeboxes, with each jukebox holding 100 CD volumes. Finally, the lead node has additional computing hardware and software that is used to support a limited amount of specialized data processing for users. The four subnodes within the Geosciences Node focus their work on specific types of geoscience data. The microwave subnode at MIT is involved with archiving planetary radar data, microwave radiometry data, and altimetry data derived from radar and laser systems. These data are available for Venus, Mars, and the Earth’s moon. The geophysics subnode at Washington University is involved
Table 1. Datasets
archived
at the Geosciences
in archiving line-of-sight (LOS) gravitational acceleration data for Mars, Venus, and the Moon. This subnode also generates and archives maps of gravity anomalies and spherical harmonics of gravity and topography data. Seismic data from the Moon are under the purview of the geophysics subnode. The thermal data subnode at Arizona State University archives thermal infrared data collected by a wide range of spaceborne instruments. These thermal observations are available for Mars, the Moon, and the satellites of the outer planets. The radio science subnode at Stanford University works on archiving bistatic radar observations, information on planetary surface characteristics derived from altimetry, radiometry, and SAR data, and radio occultation data to determine planetary radii. Such observations are available for Mars. Venus, and the Moon. Each subnode is actively developing software tools that enable users to access and navigate through the datasets housed at the subnodes. Users access the subnodes through Internet connections and WWW hypertext interfaces. Each discipline node within the PDS has an advisory council. As shown in Fig. 1, the Geosciences Node advisory group is NASA’s Regional Planetary Image Facility (RPIF) Director’s Council. The reason is that the RPIFs are primary users of geoscience data products. Thus, they can provide advice that is of an expert nature and userbased. Through the Geosciences Node the RPIFs can also make the PDS aware of their needs.
Node data and software archives During the past five years, the Geosciences Node has produced and distributed several important data archives. These archives include datasets restored from past missions, several datasets that were previously maintained
Node
Dataset Mugellun Basic Image Data Record
I5
(BIDR)
Planets
Description
Venus
SAR images for data acquired along individual orbits Mosaicked BIDR products in image format Altimetry and radiometry data acquired along orbital tracks Global image maps of altimetry. emissivity, radar reflectivity, and slopes Spacecraft accelerations due to Venus gravity along the line of sight between the spacecraft and Earth Raw altimeter data
Mugellun Mosaicked Image Data Record (MIDR) Magcllun Altimetry. Radiometry Composite Data Record (ARCDR) Mugellun Global Data Record (GxDR)
Venus Venus
Line-of-Sight Acceleration Profile Data (LOSAPDR) Mugellun Altimeter Experiment Data Record
Venus
Magellun
Venus
Record
Venus
( ALT-EDR)
Pre-Magellun
Data Collection
Geologic Remote Sensing Field Experiment (GRSFE) Data Collection c’iking Orbiter Visual Imaging Experiment Data Record (EDR) I’ikin,g Orbiter Infrared Thermal Mapper (IRTM)
Mercury. Venus, Earth. Moon, and Mars Earth
Mars Mars
Altimetry, radar images, and gravity datasets comparison to Magellun data
for
Airborne visible through microwave wavelength datasets and ground-based data for targets in southwestern U.S. Visible wavelength images of the surface, atmosphere, and moons Thermal infrared radiometer and broad-band albedo measurements of the surface and atmosphere
E.
16
A. Guinness et al. The Planetary Data System Geosciences Node
Archive volume productionby product
Archive volume distributionby product
500
!!!!!i %EN
400
B
Vikinn I EDRs
8 $ 300 % _g 200
m
MGN LOSAPDRs
2
0
1991
1992
1993
1994
Year
2000
Fig. 3. Summary of archives produced by the Geosciences Node
or produced by a planetary mission and now maintained by the Node. Archive volumes are primarily CD-WOs and CD-ROMs. See text for definition of acronyms
0
Archive volume distribution by medii
by individual investigators, and several terrestrial datasets of relevance to planetary geosciences study. The Node has also worked with the Magellan mission on the production of Magellan data product archives that have been delivered to the Geosciences Node for long-term maintenance. The current archives within the Geosciences Node are summarized in Table 1 and the sizes of these archives are shown in Fig. 3. Each archive was designed using the PDS standards that were current at the time of archive production. Each archive also went through a peer review before the archive was completed and accepted by the Node. The reviews were conducted by scientists knowledgeable of the data. The Geosciences Node archives are stored on a combination of CD-ROM and CD-W0 media. Data on CDROM has been widely distributed to the science community, whereas data on CD-W0 is electronically distributed to researchers when requested. Figure 4 shows a summary of the volume of data distributed by the Node. In addition to the production of data archives, the Node has produced several software packages for use with these data archives, as listed in Table 2. The lead node, working with the microwave and geophysics subnodes, generated a CD-ROM with 15 radar, altimetry, and gravity datasets, including extensive Earthbased radar observations of the Moon and the inner planets (Arvidson et a/., 1990). The intent of this dataset collection was to provide a set of relevant radar and gravity data for comparison to Magellan data. Thus, this CDROM is referred to as the pre-Magellan CD-ROM. The volume contains image data and data tables from the Pioneer-Venus Orbiter and Viking Orbiter missions, the Goldstone, Arecibo, and Haystack Earth-based radar observatories, and the NASA AIRSAR airborne imaging radar system. Several hundred copies of the pre-Magellan CD-ROM have been distributed to date (Fig. 4). A set of nine CD-ROMs was produced by the lead node from the Geologic Remote Sensing Field Experiment (GRSFE). This experiment was designed to acquire visible through microwave wavelength datasets from NASA aircraft over targets in the southwestern United States that have relevance as planetary analogs (Arvidson et al., 1991). During the acquisition of the airborne data, a suite
Fig. 4. Summary of the amount of data distributed by the Geosciences Node. The top graph shows the values based on media type. Values for Magellan datasets include only data distributed by the Node after release of volumes by the Magellan Project. Note in the bottom figure the dominance of CD-ROMs and the more recent emergence of data distribution on CD-W0 and by electronic means. See text for definition of acronyms
of ground-based measurements were also made to provide calibration and ground-truth for the airborne data. These ground-based data are included in the GRSFE CD-ROM archive. The intent of GRSFE was to develop comprehensive datasets to test quantitative models for estimating surface property information of relevance to the inner planets and to facilitate characterization of surfaces across different wavelength intervals. The GRSFE archive has been widely distributed to scientists interested in both planetary and Earth remote sensing studies. The lead node and the microwave, geophysics, and radio science subnodes participated heavily in the generation, validation, archiving, and distribution of Magellan datasets (Saunders et al., 1990). The close work with the MageZian mission was facilitated by the fact that several members of the Geosciences Node were also members of the Magellan science team. Specifically, they were involved
in design and validation of radar mosaic (MIDR), altimetry and radiometry (ARCDR), and global map (GxDR) data product archives on CD-ROMs. The MIDR, ARCDR, and GxDR archives are located on sets of 126, 19, and 2 CD-ROMs, respectively. The lead node continues to distribute the MIDR, ARCDR, and GxDR
I. A. Guinness
et ~1. : The Planetary
‘able 2. Software oftware
at the Geosciences
Data System Geosciences
Node
Node
name
Description
rnage Retrieval and Processing ‘ES database iravity Analysis Software 4GMDQE pfagrllun HyperMap
17
Software
Package
(IRPS)
(GASP)
noducts. The lead node is the primary archive for the ull-resolution basic image data records (F-BIDRs), radar mages on over 5200 9-track tapes. Data from these tapes Ire being systematically validated and converted to CDNOs at the lead node, with advice from the microwave md radio science subnodes. When complete, the F-BIDR nchive will consist of approximately 550 CD-WOs with a otal data volume of about 300 Gbytes. At the microwave ubnode, compressed BIDRs (C-BIDRs) and altimetry {xperiment Data Records (ALT-EDRs) are being sysematically validated and transferred to CD-WOs, to ,esult in archive collections of 124 and 71 volumes, respecively. Magelh gravity products were validated at the geophysics subnode. and a CD-W0 was generated for iata and documentation from mapping cycle 4. The geo)hysics subnode is also continuing work with Magellan napping cycles 5 and 6 gravity products. The lead node prepared data and documentation for m archive of 32 CD-ROMs containing Viking Orbiter 1 VOl) Visual Imaging Subsystem Experiment Data Rec)rd (EDR) images as a data node to the PDS Image Node Guinness et a/.. 1990). Data for the Viking Orbiter 2 VO2) images were prepared by the PDS Image Node. A otal of 50,500 images are included in the VOl and V02 mage archive on a collection of 46 CD-ROMs. The image lata are stored in a compressed format using a Huffman Trst-difference compression algorithm that is lossless. To ‘acilitate rapid browsing of the image collection, subsampled versions of each image are included. The archive also contains software for decompressing the EDR Images. Since the Viking Orbiter image archive consists of raw EDR image data, it is currently maintained by the PDS Image Node. The thermal subnode is in the process of restoring the Viking Orbiter Infrared Thermal Mapper (IRTM) database. This dataset consists of about 600 Mbytes of thermal infrared and broad-band albedo measurements of the martian surface and atmosphere. After restoration peer review of the 1RTM archive. it will be distributed along with software to access and analyze the data on a set of two CD-ROMs. The microwave subnode has been active in working with individuals from the Russian Institute of Radiotechnology and Electronics and the Moscow Power Institute to archive Russian Venera 15 and 16 data on several CD-WOs. This dataset will include radar and altimetry observations of the surface of Venus. The PDS Educational CD-ROM, called Welcome to the Planets. has been developed as a joint effort between the Geosciences Node as the science lead and the PDS Central Node as the technology coordinators and pro-
Includes image processing software developed by Image Node. Used to make specialized products Access to spectral datasets Modeling and inversions of gravity data Display Magellan ARCDR, GxDR, and MIDR datasets Quick-look tool for searching and accessing Mugdan MIDR and GxDR datasets on a Macintosh
ducers of the disk. The CD-ROM contains approximately 200 planetary images and diagrams of spacecraft, along with information about the images and the planets. It is designed for educational use at the high school and collegiate levels. The Geosciences Node has developed a number of software packages for distribution to the community. The lead node developed and now maintains the Image Retrieval and Processing System (IRPS), a combination of an on-line catalog for image data and image processing software for analysis of the data. The catalog includes detailed information about Viking Orbiter and Voyager images, as well as general information about other missions. The image processing software is based on the PICS system developed by the USGS in Flagstaff. IRPS is used by the RPIFs and others in the planetary science community.The microwave subnode has developed the Magellan HyperMap program for the Macintosh. a quicklook tool for accessing and displaying MIDR and GxDR products from the Magellan CD-ROMs, along with the Magellan Experimenters’ Notepad (Fig. 5). HyperMap has been distributed to the RPIFs and other PDS users. The geophysics subnode has participated in the development of gravity data analysis software known as GASP for use with Magellan Line-of-Sight Acceleration Profile Data Record (LOSAPDR) products. GASP does both forward modeling of LOS acceleration data and inversions to extract information about subsurface properties and dynamics. The thermal subnode has developed database management software for satellite-derived and laboratory multispectral data. Designed for use with data from the Mars Global SurzleJ,or Thermal Emission Spectrometer (TES) instrument, the software is called the TES Database. but can be used for any spectral data, including the Viking Orbiter IRTM archives. It is designed to use PDS-labeled data products.
Node services The Geosciences Node is involved in a number of activities to assist its users besides data archiving and distribution. These services include developing and maintaining data product catalogs, working with PDS as a whole to develop archiving standards, and interacting with educators and the public. The Node has electronic catalogs that allows users to conduct searches and place orders for Node archives, including datasets, documentation, and software. The catalogs use relational database management
E. A. Guinness
CD-ROM Uolume: Starting Orbit: Ending Orbit: Center Longitude: Center Latitude: Incidence Angle: Illuminated from:
et al. : The Planetary
MG-0048 1674 2218 299.393674 74.865415 20.1’ - 24.7” left
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Fig. 5. Example illustrating the Mngellan HyperMap capabilities. Top screen shows information for one MIDR product. including the location of features within the mosaic. Bottom screen shows uplink and downlink comments and a summary of commands along the orbital track for orbits 376403
software and the PDS data dictionary. All data archives under the Geosciences Node purview will be included in the Node catalogs. Currently, the catalogs have information about Magellan radar, altimetry, and gravity data products and Viking Orbiter and Voyager images. The lead node is also developing a catalog of Clementine data
products of the Moon. Working with the Image Node, the catalog will include image, altimetry, and gravity data products. The operation of the catalog will probably be split between the Geosciences lead node and image Node, using distributed database capabilities. Scientists who are registered users of the PDS can access
E. A. Guinness
et nl. : The Planetary
Data System Geosciences
the Geosciences Node catalogs through the PDS Central Node catalog system. Access is via the Internet using a remote login from the Central Node to the Geosciences Node. A more convenient and more widely accessible method of electronically connecting to the Geosciences Node on-line services is via the WWW using a browser program such as Mosaic. This method of access is available to anybody with Internet access and WWW browser software. The URL (Uniform Resource Locator) for the Geosciences lead node is “http://wwwpds.wustl.edu/“. The information available through the lead node WWW interface includes information on available datasets at the lead node and how to obtain them, access to the Node’s catalog system, access to geosciences subnode WWW interfaces, and a list of personnel at the lead node and how to contact them. From the Geosciences Node WWW interface, users can also connect to the PDS Central Node WWW interface. which provides links to all the other PDS discipline nodes. Users can search the Node catalogs for data products through categories such as product name and type, time of acquisition, location on a planet. and geographic feature name. Figure 6 shows schematically how the Node catalogs can be searched using the Magellan catalog as an example. Figure 7 shows an example screen from the user interface to the Magellan catalog. Users can submit orders for data products found in the catalogs. Data ordered through the catalogs are distributed either by mailing copies of CD-ROMs, by copying data to tape or CD-WO, and by electronic transfer over the Internet. With more users gaining access to the Internet, the Node is attempting to encourage greater use of electronic data transfer. For example, a large portion of the Magellan F-BIDR dataset is on-line in a set of CD jukeboxes that hold 300 CD volumes. Data in these jukeboxes can be ordered through the Magellarl catalog and then electronically transferred to the user. Figure 8 shows schematically how a user would work with the Node catalog system to electronically transfer data from the on-line database back to his local computer. Node personnel have been active in the development of PDS standards that are important to geosciences datasets (e.g. map projections, coordinate systems, and label formats) and in the development of processes related to generation and validation of archives. Such standards and processes are valuable in ensuring that the PDS produces high-quality, well-documented data archives for the science community. The Node has also been very active in working with mission personnel in Europe and Russia on issues related to archive production. Although not formally part of the PDS charter. education and public outreach activities using PDS datasets are an important component of what the PDS is doing. Thus, the Geosciences Node has been involved in outreach activities that include operating WWW servers at the lead node and each of the subnodes. The microwave subnode server provides access to NASA archives and allows browsing of Magellan MIDR images. The thermal subnode provides information of the current status of planetary missions. The lead node has been working with The Planetary Society on the Marslink program, which produces classroom exercises about Mars science. The
Node
19
HOW TO NAVIGATE THE MAGELLAN CATALOG
BY
Feature
BY
Time
Look for orbiis covering time range
I
Orbit Range
Look for orbits or maps covering lat-ion boundaries I
%it Map Product ID
BY
Name
Media, Volume ID, File name
Fig. 6. Flow diagram illustrating the Mqrlkm catalog capabilities. Major search categories are shown on the left and include searching by feature name. by time. by location, by orbit. and by product name. Searches can start at any level. The arrows are intended to show connections between the components of the catalog and the flow of the search to find a specific set of products. Data products found by such searches can be ordered through the catalog. Orders are filled by CD-ROM, CD-WO. and a growing amount of electronic data transfer using the Internet
Marslink materials are available on-line through the lead node WWW server. In addition. the Node makes selected PDS datasets available to educators and the public.
Node data archiving and software plans The Geosciences Node plans to continue to be very active in archiving datasets over the next several years. The new archives will include data restored from past missions such as Viking, Pioneer- Venus, and Apollo, data from recently complete missions such as Clmentinr and Magellan, and data from missions such as Mars Global Surrq~or and the Discovery class Lunar Prospector mission that should return data over the next few years. The Node expects to be active in interfacing with on-going missions on issues of archive production. The Node will also be working with its international partners to make geosciences data from international missions available through the PDS. Table 3 lists a summary of datasets that the Geosciences Node plans to archive over the next five years. In addition,
E. A. Guinness
et al. : The Planetary
Data System Geosciences Node
Fig. 7. An example of a search screen from the Magellun catalog. This screen is used to locate geographic features on Venus. Features can be found by specifying name. type. or area of the planet. The information returned by the search includes the feature location, its size, and the origin of the name. The catalog can be directed to map to the data products that cover the features located by the search
ELECTRONIC ORDER AND DELIVERY Quenf
FTP
Read Data from CD Jukebox
Fig. 8. Flow diagram illustrating the Geosciences Node electronic order and data distribution system. This mechanism is used for data archived on CD-W0 media and stored on-line in the Node’s CD jukeboxes. Users query the Node catalog to select data and submit an order for that data. The system automatically transfers the data from CD-W0 in a jukebox to a staging area on disk. Moving products from CD to hard disk is necessary in order to handle multiple data orders at one time. After products are staged, an electronic mail message is sent to the user to inform him that the data are ready for transfer. The user is sent instructions on how to transfer the data using ftp. Finally, the user issues commands to transfer the data back to his local computer
software tools will be developed as needed for use with datasets archived at the Node. Even though the Magellan mission has ended operations, there are several Magelfan datasets that still have to be archived and cataloged so that they c’dn be made available for distribution. These datasets include the Magellan SCVDR dataset (vector representations of scattering properties of surface), global maps of surface properties generated from the SCVDRs, Magellan bi-static radar observations, LOS gravity products from the later part of the mission, and spherical harmonic expansion models of the gravity and topography fields. The datasets will be initially archived on CD-W0 and distributed electronically through the Node catalog. If a large number of requests for the data are made, some of the data will be transferred to CD-ROM for wide distribution. There are several additional Venus datasets from past missions that the Node plans to archive within the PDS. The Pioneer- Venus altimetry and emissivity datasets. including the raw data, and the gravity datasets will be restored and archived. The archiving of Venera 15 and 16 altimetry, radiometry, and radar data will be completed, with help from our Russian colleagues. Earth-based radar observations of Venus are an important group of datasets. The Node will also be working to archive these observations, primarily Arecibo, Goldstone, and VLA data. Archiving of data from the moon will concentrate on digital data from the Clementine, Apollo, and Lurlar Prospector missions. The Node will continue to work closely with the Image Node on Clementine image archives. The Geosciences Node will archive Clementine derived image datasets (e.g. calibrated multispectral image mosaics), altimetry data, and gravity datasets. Ciementk bi-static
E. A. Guinness
et (I/. : The Planetary
Table 3. Geosciences
Node datasets
Data System Geosciences
Node
71
to be archived
Dataset
Planets
Description
.hlugellun SCV DR Mugellun Bi-static Radar
Venus Venus
l’c~rtz 15. I6 Data P ior~rr- I hu.s Radar Data Pioneer- I’errus Gravity Data Ckmenrinr Altimetry Data Clementirw and .4pollo Gravity
Venus Venus Venus Moon Moon
Surface characteristics derived from SAR and altimetry data Microwave transmissions from spacecraft reflected from planet surface and received on Earth Radar, altimetry, and radiometry data Radar backscatter data Line-of-sight accelerations due to gravity as orbital tracks Orbital tracks and gridded map products Line-of-sight accelerations due to gravity as orbital tracks and gridded map products Microwave transmissions from spacecraft reflected from planet surface and received on Earth Multispectral image mosaics Gamma Ray, Neutron Spectrometer. Alpha Particle. and Radio Science datasets Experiment Data Record (EDR) images and mosaics Microwave transmissions from spacecraft reflected from planet surface and received on Earth Infrared radiometry and spectroscopy Orbital tracks and gridded map products Thermal infrared emission spectra Line-of-sight accelerations due to gravity as orbital tracks and gridded map products Mosaicked image products
Cker~erzrinc, and .4170//o Bi-static
Data Radar
Moon
C(ementirw Derived Image Data Lurlur Pro.~pi~tor
Moon Moon
c’ikiri~qLmder Images Viking Bi-static Radar
Mars Mars
Marirwr 6. 7. and 9 Infrared Data MGS Laser Altimeter (MOLA) Data MGS Thermal Emission Spectrometer MGS Gravity Data
Mars Mars Mars Mars
MGS Derived
Image Data
(TES) Data
Mars
radar data will be archived. Many of the Clementirle archives will be placed on CD-WOs. made available online through our catalog, and transferred to CD-ROMs if widespread distribution is need. The Geosciences Node will have an active role in working with the Lunar Prospector mission to archive data products from the Gamma Ray, Neutron. Alpha Particle, and Radio Science experiments. Finally, the Node will archive Apollo 17 Infrared Scanning Radiometer (ISR) data, along with Apollo bistatic radar and gravity data. For Mars datasets, the Node will conduct several efforts in archiving past mission data and in planning for several Mars missions that should return data in a few years. The Node will restore and archive existing thermal radiometer and spectrometer datasets for Mars, specifically working on Mtrrirwr 6 and 7 IRS and Mariner 9 IRIS data. The Viking Lander Camera Experiment Data Records will also be archived with help from the Image Node. Further, the I=ikiq Ohitc~r bi-static radar and gravity observations will be archived. As with Venus. the Node will archive Earth-based radar observations of Mars, including Arecibo, Goldstone. and VLA datasets. Both the spacecraft mission and Earth-based data will be very important datasets for use in planning and in analyzing data from upcoming Mars missions. The Geosciences Node expects to be heavily involved in the archiving of Mars Global Suweyor (MGS) data. Specifically. the TES (Thermal Emission Spectrometer) data will be archived and released with relevant software as on-line products and as CD-ROMs. The Node expects to archive MOLA (Laser Altimeter) observations in much the same way. Derived image products (i.e. calibrated image mosaics) will be archived and cataloged by the Geosciences Node. In addition, the Node will archive MGS gravity data. including line-of-sight Doppler accel-
erations and spherical harmonic expansions. Finally, the Geosciences Node expects to be involved in archiving Mars Pathfinder data. The whole Mars Pathfinder archive could be published on several CD-ROMs. The Geosciences Node is a primary PDS interface to the growing activity related to international access to Mars datasets. Specifically, working with our colleagues in Germany and Russia. the Node expects to work on a distributed catalog called the International Mars Database (IMDB). A user would be able to conduct searches for Mars data from several sites around the world and not need to know that the catalog is distributed. Some of the datasets from European and Russian missions that may be part of the IMDB include several Pkohos mission datasets such as near-infrared spectroscopy and thermal infrared radiometry. and Mum-96 datasets such as imaging. visible and near-infrared spectroscopy, and thermal infrared radiometry. In addition, all the Mars datasets housed at the Geosciences Node would be included. Orders could be placed at any site and filled by the site that archives the data. The IMDB will come to fruition when Mcrrs Ghhol SurreJ,or and Mars-96 data become available. The Geosciences Node has found that archives are most useful if they are accompanied by software packages to process and analyze the data. Thus, a number of packages will be developed over the next five years. For example, a significant effort will be the TES database software to display and analyze Mars spectral datasets. culminating in the ability to extract spectra from the complex TES archives that will be returned by the MGS mission. In addition, the Magellarz stereo toolkit software. which was developed for Magellan investigators. will be updated and made available to NASA-sponsored researchers. It will have the added capability to handle F-BIDRs in rangeDoppler coordinates.
22 Summary
The philosophy of the Geosciences Node and the emphasis of the work it does can be summarized by the following points. (1) The Node is focused on archive production and distribution of planetary geosciences data from spacecraft missions and some Earth-based observations. Archives are generated on CD-WOs and made available through the Node’s on-line catalog. Popular datasets will migrate to CD-ROMs for distribution. Some datasets will be placed on CD-ROMs directly if wide distribution is needed. The Node maintains the expertise about its datasets in order to assist researchers in the use of the data. (2) The Node attempts to establish close working relationships with missions. Working with missions while archives are being designed and produced will help ensure that high quality, well documented archives are produced. One way that the Node has been able to develop such relationships with missions is by having Node personnel involved in both the missions and the PDS. (3) The use of datasets is enhanced by the availability of software tools. The Geosciences Node develops appropriate software for access and analysis of certain types of datasets such as spectral and gravity datasets. (4) The Node develops and maintains on-line catalogs of datasets within the Node. The catalogs contain information about individual data products within a dataset. The catalogs are intended to assist users in moving through large datasets and in selecting subsets of data. (5) The Geosciences Node is active in developing international cooperation to provide access for researchers to international datasets. The Node has placed particular emphasis on international datasets for Mars and is work-
E. A. Guinness et al. : The Planetary Data System Geosciences Node ing to create an international Mars Database in conjunction with European and Russian colleagues. (6) Public and educational outreach is an important aspect of the Geosciences Node efforts. The Node
attempts to provide selected data products to the public and educators to keep them aware of recent advances in the field of planetary geosciences. Acknowledgements. The authors are supported by JPL Contract 958756 to Washington University for PDS Geosciences Node
tasks. Thanks to an anonymous thoughtful review of this paper.
reviewer for providing
a
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Data, CD-ROM Vol. USA_NASA_PDS_MG_lOOl, NASA Planetary Data System, JPL, Pasadena, California, 1990. Arvidson, R. E., Dale-Bannister, M. A., Guinness, E. A., Slavney, S. H. and Stein, T. C., Archive of Geologic Remote Sensing
Field Experiment Data-Release 1.O,CD-ROM Vol. USANASA_PDS_GROOOl, NASA Planetary Data System, JPL, Pasadena, California, 1991. Guinness, E. A., Slavney, S., Eliason, E., Martin, M. and Hyon, J., Archive of Images from NASA’s Viking Orbiter 1 and 2 Missions, CD-ROM Vol. USA_NASA_PDS-VO-100 I, NASA Planetary Data System, JPL. Pasadena, California, 1990. Lee, S., The Planetary Data System, Rev. of Geophysics, April Supplement, U.S. National Report to International Union of Geodesy and Geophysics 1987-1990, pp. 338-341. 1991. Saunders, R. S., Pettengill, G. H., Arvidson, R. E., Sjogren, W. L., Johnson, W. T. K. and Pieri, L., The Magellan Venus Radar Mapping Mission. J. Geophys. Res. 95, 833998355,
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