Engineering topics

Candey, Robert M.

Publications and source records attributed to Candey, Robert M..

11 records

NASA NTRS2011

Science Enabling Roles and Services of SPDF

The current Heliophysics Science Data Management Policy defines the roles of the Space Physics Data Facility (SPDF) project as a heliophysics active Final Archive, a focus for critical data infrastructure services and a center of excellence for data and ancillary information services. This presentation will highlight some of our current activities and our understanding of why and how our services are useful to researchers, as well as SPDF's programmatic emphasis in the coming year. We will discuss how. in cooperation with the Heliophysics Virtual discipline Observatories (VxOs), we are working closely with the RBSP and MMS mission teams to support their decisions to use CDF as a primary format for their public data products, to leverage the ongoing data flows and capabilities of CDAWeb (directly and through external clients such as Autoplot) to serve their data in a multi-mission context and to use SSCWeb to assist community science planning and analysis. Among other current activities, we will also discuss and demonstrate our continuing effort to make the Virtual Space Physics Observatory (VSPO) service comprehensive in all significant and NASA relevant heliophysics data. The OMNI and OMNI High Resolution datasets remain current and heavily cited in publications. We are expanding our FTP file services to include online archived non-CDF data from all active missions, which is a re-hosting of this function from NSSDC's FTP site. We have extended the definitions of time in CDF to unambiguously and consistently handle leap seconds. We are improving SSCWeb for much faster per1ormance, more capabilities and a web services inter1ace to Query functionality. We will also review how CDAWeb data can be easily accessed within IDL and new features in CDAWeb.

McGuire, Robert E.↗

NASA NTRS2010

Common Data Format (CDF) and Coordinated Data Analysis Web (CDAWeb)

The Coordinated Data Analysis Web (CDAWeb) data browsing system provides plotting, listing and open access v ia FTP, HTTP, and web services (REST, SOAP, OPeNDAP) for data from mo st NASA Heliophysics missions and is heavily used by the community. C ombining data from many instruments and missions enables broad resear ch analysis and correlation and coordination with other experiments a nd missions. Crucial to its effectiveness is the use of a standard se lf-describing data format, in this case, the Common Data Format (CDF) , also developed at the Space Physics Data facility , and the use of metadata standa rds (easily edited with SKTeditor ). CDAweb is based on a set of IDL routines, CDAWlib . . The CDF project also maintains soft ware and services for translating between many standard formats (CDF. netCDF, HDF, FITS, XML) <! .

Candey, Robert M.↗

NASA NTRS2007

Capabilities of NASA's Space Physics Data Facility as Resources to Enable the Heliophysics Virtual discipline Observatories (VxOs)

SPDF now supports a broad range of data, user services and other activities. These include: CDAWeb current multi-mission data graphics, listings, file subsetting and supersetting by time and parameters; SSCWeb and 3-D Java client orbit graphics, listings and conjunction queries; OMNIWeb 1/5/60 minute interplanetary parameters at Earth; product-level SPASE descriptions of data including holdings of nssdcftp; VSPO SPASE-based heliophysics-wide product site finding and data use;, standard Data format Translation Webservices (DTWS); metrics software and others. These data and services are available through standard user and application webservices interfaces, so middleware services such as the Heliophysics VxOs, and externally-developed clients or services, can readily leverage our data and capabilities. Beyond a short summary of the above, we will then conduct the talk as a conversation to evolving VxO needs and planned approach to leverage such existing and ongoing services.

McGuire, Robert E.↗

NASA NTRS2006

New SPDF Directions and Evolving Services Supporting Heliophysics Research

The next advances in Heliophysics science and its paradigm of a Great Observatory require an increasingly integrated and transparent data environment, where data can be easily accessed and used across the boundaries of both missions and traditional disciplines. The Space Physics Data Facility (SPDF) project includes uniquely important multi-mission data services with current data from most operating space physics missions. This paper reviews the capabilities of key services now available and the directions in which they are expected to evolve to enable future multi-mission correlative research. The Coordinated Data Analysis Web (CDAWeb) and Satellite Situation Center Web (SSCWeb), critically supported by the Common Data Format (CDF) effort and supplemented by more focused science services such as OMNIWeb and technical services such as data format translations are important operational capabilities serving the international community today (and cited last year by 20% of the papers published in JGR Space Physics). These services continue to add data from most current missions as SPDF works with new missions such as THEMIS to help enable their unique science goals and the meaningful sharing of their data in a multi-mission correlative context. Recent enhancements to CDF, our 3D Java interactive orbit viewer (TIPSOD), the CDAWeb Plus system, increasing automation of data service population, the new folding of the VSPO effort into SPDF and our continuing thrust towards fully-functional web services APIs to allow ready invocation from distributed external middleware and clients will be shown.

McGuire, Robert E.↗

NASA NTRS2006

What Do Our Users Want? Perspectives on Understanding and Meeting User Needs for Multi-Mission Data Services

The Sun-Earth Connection Active Archive (SECAA) project of NASA's Space Physics Data Facility operates a range of unique and heavily used multi-mission data services in support of the large-scale science objectives of the Great Observatory, including services such as CDAWeb, the CDAWeb Plus client, SSCWeb, OMNIweb and the CDF data format. In developing and operating these services, we have encountered and continue to struggle with a wide range of issues such as balancing scope and functionality with simplicity and ease of use, understanding the effectiveness of our choices and identifying areas most important for further improvement. In this paper, we will review our key services and then discuss some of our observations and new approaches to understanding and meeting user data service requirements. Some observations are obvious but may still have substantial implications; e.g. functionality without information content is of little user interest, which has led to our recent emphasis on development of web services interfaces, so the content and functionality we already serve is readily and fully available as a building block for new services. Some observations require careful design and tradeoffs; e.g. users will complain when they are offered interfaces with limited options but users are also easily intimidated and become lost when offered extensive options for customization. Some observations remain highly challenging; e.g. a comprehensive multi-mission, multi-source view of all data and services available easily produces a daunting list, but a more selective view can easily lead users to overlook available and relevant data. It is often difficult to obtain and meaningfully interpret measures of true productive usage and overall user satisfaction, even with a variety of techniques including statistics, citations, case studies, user feedback and advisory committees. Most of these issues will apply to and may even be more acute for distributed implementation architectures.

McGuire, Robert E.↗

NASA NTRS2005

Space Physics Data Facility Web Services

The Space Physics Data Facility (SPDF) Web services provides a distributed programming interface to a portion of the SPDF software. (A general description of Web services is available at http://www.w3.org/ and in many current software-engineering texts and articles focused on distributed programming.) The SPDF Web services distributed programming interface enables additional collaboration and integration of the SPDF software system with other software systems, in furtherance of the SPDF mission to lead collaborative efforts in the collection and utilization of space physics data and mathematical models. This programming interface conforms to all applicable Web services specifications of the World Wide Web Consortium. The interface is specified by a Web Services Description Language (WSDL) file. The SPDF Web services software consists of the following components: 1) A server program for implementation of the Web services; and 2) A software developer s kit that consists of a WSDL file, a less formal description of the interface, a Java class library (which further eases development of Java-based client software), and Java source code for an example client program that illustrates the use of the interface.

Candey, Robert M.↗

NASA NTRS2005

Generating Animated Displays of Spacecraft Orbits

Tool for Interactive Plotting, Sonification, and 3D Orbit Display (TIPSOD) is a computer program for generating interactive, animated, four-dimensional (space and time) displays of spacecraft orbits. TIPSOD utilizes the programming interface of the Satellite Situation Center Web (SSCWeb) services to communicate with the SSC logic and database by use of the open protocols of the Internet. TIPSOD is implemented in Java 3D and effects an extension of the preexisting SSCWeb two-dimensional static graphical displays of orbits. Orbits can be displayed in any or all of the following seven reference systems: true-of-date (an inertial system), J2000 (another inertial system), geographic, geomagnetic, geocentric solar ecliptic, geocentric solar magnetospheric, and solar magnetic. In addition to orbits, TIPSOD computes and displays Sibeck's magnetopause and Fairfield's bow-shock surfaces. TIPSOD can be used by the scientific community as a means of projection or interpretation. It also has potential as an educational tool.

Candey, Robert M.↗

NASA NTRS1995

Visualization of International Solar-Terrestrial Physics Program (ISTP) data

The International Solar-Terrestrial Physics Program (ISTP) is a multispacecraft, multinational program whose objective is to promote further understanding of the Earth's complex plasma environment. Extensive data sharing and data analysis will be needed to ensure the success of the overall ISTP program. For this reason, there has been a special emphasis on data standards throughout ISTP. One of the key tools will be the common data format (CDF), developed, maintained, and evolved at the National Space Science Data Center (NSSDC), with the set of ISTP implementation guidelines specially designed for space physics data sets by the Space Physics Data Facility (associated with the NSSDC). The ISTP guidelines were developed to facilitate searching, plotting, merging, and subsetting of data sets. We focus here on the plotting application. A prototype software package was developed to plot key parameter (KP) data from the ISTP program at the Science Planning and Operations Facility (SPOF). The ISTP Key Parameter Visualization Tool is based on the Interactive Data Language (IDL) and is keyed to the ISTP guidelines, reading data stored in CDF. With the combination of CDF, the ISTP guidelines, and the visualization software, we can look forward to easier and more effective data sharing and use among ISTP scientists.

Kessel, Ramona L.↗

NASA NTRS1992

Onsite analysis of data from the Dynamics Explorer (DE) spacecraft

The tasks performed by ARC Professional Services Group, Inc. fell into five parts: (1) dynamics explorer (DE) data analysis and modeling; (2) DE project support; (3) chemical release observations support; (4) VLF emissions and plasma instability studies; and (5) modeling of planetary radio emissions. Some recommendations for future considerations are also addressed.

Fung, Shing F.↗

NASA NTRS1990

Directions in gamma-ray spectroscopy

Current and future instrumentation for gamma-ray spectroscopy in the spectral range from 10 keV to 10 MeV is described. New technologies for Germanium (Ge) spectrometers and emerging detector technologies are highlighted. Scientific objectives are considered, with emphasis on capabilities beyond those of the Nuclear Astrophysics Explorer (NAE). A list of instrument requirements is given. Technologies under development for an NAE-era spectrometer are presented. Spectrometers beyond NAE and other types of future technologies are discussed, and a partial list of current and future spectrometers is provided.

Gehrels, Neil↗

NASA NTRS1990

Low background gamma-ray spectrometer

The next-generation gamma-ray spectrometer after the planned Nuclear Astrophysics Explorer (NAE) could be based on the moon to use the lunar regolith for shielding the detectors from cosmic rays and neutrons. This increased shielding over what could reasonably be put in low-earth orbit would provide a narrow line sensitivity (3 sigma) of about 2 x 10 exp -7 photons/sq cm s at 1 MeV in 10 exp 6 s, which is about 10 times better than the NAE and 100 times better than GRO/OSSE.

Gehrels, Neil↗