T. A. King

SPASE 2.0: a standard data model for space physics

SPASE—for Space Physics Archive Search and Extract—is a group with a charter to promote collaboration and sharing of data for the Space Plasma Physics community. A major activity is the definition of the SPASE Data Model which defines the metadata necessary to describe resources in the broader heliophysics data environment. The SPASE Data Model is primarily a controlled vocabulary with hierarchical relationships and with the ability to form associations between described resources. It is the result of many years of effort by an international collaboration (see http://www.spase-group.org) to unify and improve on existing Space and Solar Physics data models. The genesis of the SPASE group can be traced to 1998 when a small group of individuals saw a need for a data model. Today SPASE has a large international participation from many of the major space research organizations. The design of the data model is based on a set of principles derived from evaluation of the existing heliophysics data environment. The development guidelines for the data model are consistent with ISO-2788 (expanded in ANSI/NISO Z39.19) and the administration for the data model is comparable to that described in the ISO standards ISO-11179 and ISO-20943. Since the release of version 1.0 of the data model in 2005, the model has undergone a series of evolutions. SPASE released version 2.0 of its data model in April 2009. This version presents a significant change from the previous release. It includes the capability to describe a wider range of data products and to describe expert annotations which can be associated with a resource. Additional improvements include an enhanced capability to describe resource associations and a more unified approach to describing data products. Version 2.0 of the SPASE Data Model provides a solid foundation for continued integration of worldwide research activities and the open sharing of data.

An internationally distributed cloud for science: the cloud-enabled space weather platform

The purpose of the Cloud-Enabled Space Weather Platform (CESWP) project is to bring the power and flexibility of cloud computing to space weather physicists. The goal is to lower the barriers for the physicists to conduct their science. That is, to make it easier to collaborate with other scientists, develop space weather models, run simulations, produce visualizations and enable provenance. Success of the project is measured by the broad acceptance and use of the platform by the space weather science community. To deliver cloud computing and storage, infrastructure as a service, the project has built an internationally distributed cloud based on Eucalyptus [1]. To provide a graphical user interface for the physicists to interact with we selected the Groovy programming language and the Grails web framework. To construct the software we followed the Scrum agile software development methodology. This paper will report on the motivation and risks of such an undertaking. It will also report on the suitability of Eucalyptus as a cloud framework and the utility of the tools used to build an application on top of it.

The morphology and architecture of a distributed data system

Members of the Planetary Plasma Interactions Node of the Planetary Data System (PDS/PPI) have designed and implemented a data system which allows for distributed access to centralized data, centralized access to distributed data, and distributed access to distributed data. While these types of data access might seem like completely different problems, they are not. The only differences are the number of access pathways to and from the data. By adopting a client/server model of system design we have been able to provide transparent access to both distributed and centralized data. In addition, by carefully choosing the location of the division between the client and server, the response of the system as a whole can be greatly enhanced. For example, the user interface is a stand‐alone application which configures itself according to information stored with the data sets and the data sets may be local or distributed. All keystroke interactions are handled on the local machine and the end results of menu selec...

Using Virtual Observatories for Heliophysics Research

Scientific satellites, balloons, ground-based instruments, and other observational platforms are producing rich streams of data about the Earth and space. Ensuring widespread access to such data has led to the development of a new type of observatory: the virtual observatory. Existing only in cyberspace, virtual observatories are Web-based interfaces that point users to online data repositories. More important, they allow users not only to access and view multiple sources of information at the same time but also to cross-compare data to build new insights.

The design and implementation of scalable data systems and incremental data sets

Today’s space physics data systems are faced with a vast quantity of data and researchers need to have ready access to the data. These needs are compounded by the variety of ways in which researchers do their work. One way to provide ready access to data is through a central store. Even when there is an adequate central store of the data, researchers usually require local access to the data for performance reasons. Since the volume of data which may be distributed could be large it is very beneficial to distribute a data system with the data. Since system resources vary from researcher to researcher a data system must be scalable to the size of the resources on the system.Developers and researchers at the Planetary Plasma Interactions (PPI) Node of the Planetary Data System (PDS) have addressed this problem and have designed and implemented a scalable data system which uses incremental data sets. This system allows collections of data to be brought on‐line from archival media and merged with other collect...

Automating database management for distributed database systems

The management of large databases can be a time consuming and tedious task without tools to automate the process. In order to facilitata the process, a database design philosophy which is consistent with application objectives must be adopted. The Planetary Plasma Interactions (PPI) Node of the Planetary Data System (PDS) provides users with a software application which allows for rapid retrieval (for examination or extraction) of datasets which are distributed and which may exist in more than one location simultaneously. In addition, the application software, which interacts with both a local and a centralized database management system (dbms) via a client‐server architecture, also is distributed. The basic problem lies in keeping all of the information current in a dynamic data environment so that the application software, regardless of its location, can access any data in the system with the greatest possible throughput. In addressing this problem the PDS/PPI Node has adopted a standardized architectur...

The design, development and operation of a distributed data inventory system

The design, development and operations of a distributed data inventory system is a concern of many government agencies and commercial enterprises. All are searching for ways to harness the information and data resources that are available, as well as provide a framework for bringing future data into an unifying structure. We provide a discussion of the design, development and operation of a system which can be used to build, manage and access distributed data inventories. We discuss the major decisions we made, why we made those decisions and what the end product of our efforts has been. Currently the system we describe is being used as the data access system for the Plasma Interactions Node (PDS/PPI) of NASAs Planetary Data System in order to provide access to fields and particles data returned from NASAs planetary missions.<<ETX>>

PIPE: An intelligent scientific data preparation assistant

Scientific data preparation is the process of extracting usable scientific data from raw instrument data. This task involves noise detection (and subsequent noise classification and flagging or removal), extracting data from compressed forms, and construction of derivative or aggregate data (e.g., spectral densities or running averages).This paper describes the PIPE system. PIPE provides intelligent assistance developing scientific data preparation plans developed using Master Plumber, a general language for scientific data processing plans. PIPE provides this assistance capability by using a process description to create a dependency model of the scientific data preparation plan. This dependency model can then be used to verify syntactic and semantic constraints on processing steps to perform limited plan validation. PIPE also provides capabilities for using this model to assist in debugging faulty data preparation plans. In this case, the process model is used to focus the developers’ attention upon tho...

The Planetary Plasma Interactions Node of the Planetary Data System

Abstract Five years ago NASA selected scientists at UCLA to form the Planetary Plasma Interactions (PPI) Node to help the scientific community locate, access and preserve particles and field data from planetary missions. Since planetary plasma data are varied and require expertise in many areas the PPI Node is distributed with an Outer Planets Subnode at the University of Iowa, an Inner Planets Subnode at UCLA and a Radio Astronomy Subnode at GSFC. The PPI Node has tried to serve the science community by providing them with high quality data products. It has worked with missions and individual scientists to secure the highest quality data possible and to thoroughly document it. The PPI Node has validated the data, placed it on long lasting media and made sure it was properly archived for use. So far it has prepared and archived over 1011 bytes of data and has produced 171 CD-ROMs with peer reviewed data. In so doing an efficient system has been developed to prepare and archive the data and thereby enable to steadily increase the rate at which the data are archived. Although the PPI Node produced a substantial archive during the initial five years, it has an even larger amount of work in progress. This includes preparing CD-ROM data sets with all of the Voyager, Pioneer and Ulysses data at Jupiter and Saturn. It is also completing the Pioneer Venus data restoration. The Galileo Venus archive and radio science data from Magellan will be prepared early in 1995. It is assisting the Small Bodies Node of PDS in the preparation of comet data and with the preparation of data from the comet Shoemaker-Levy 9 collision with Jupiter. Asteroid data from Gelileo will also be archived. In addition to providing the data, users have been provided with software tools to manage and read the data which are computer, operating system and data format independent. Scalable systems have been developed so that the same software used to manage and access the data for the entire PPI Node can be used by individual investigators to manage the data on a single CD-ROM thereby greatly reducing the software development effort for both the PPI Node and users. This software is delivered with the disks. The PPI Node data holdings are available over the Internet. They can be accessed through the World Wide Web (WWW) at Universal Resource Locator (URL) http://www.igpp.ucla.edu/ssc/pdsppi/Welcome.html. Users without a WWW browser can use the WWW interface by signing into the host “pdsppi.igpp.ucla. edu” as “pdsuser”.

Designing science web sites

From a scientist’s viewpoint a web site is one tool used to conduct research. From an artist’s viewpoint web sites are a form of visual composition. From a developer’s point of view a web site is a type of application. While web sites are a relatively new medium with a particular set of constraints, they do adhere to the same basic design principles that apply to other art forms. These design principles are the basic assumptions that affect the arrangement of elements within a composition. A successful design uses the principles and elements to achieve a visual goal in the composition. A web site designed for scientists has unique properties which are not shared by many other types of web sites. These properties influence the overall visual design of the web sites. Recently at the Institute of Geophysics and Planetary Physics at UCLA undertook a re-design of a number of its websites. In the effort, the use of visual design principles combined with the properties of a science web site were put to the test. In all, six different web sites were designed each with a difference science focus. We describe the process used to design the web sites which involve forming teams of designers, scientists and developers. We present example pages from each design and conclude with a discussion of what was learned during the process.