From ViRBO

1 Introduction

The Data section below has a complete list of available data. Many previously inaccessible data sets are now available and we plan to continuously add new tools, data sets, and services of interest to radiation belt scientists. If you have any suggestions, requests, or questions, email them to virbo@virbo.org.

ViRBO Status

This is the version 1.0 alpha release of ViRBO. The "alpha" designation means that the infrastructure of the VxO is nearly complete.

In general, many ViRBO web pages are functional. Some features are not available for all data sets. To see an example of a data set with all of the possible features enabled (except the fully enabled data subsetting and filtering server), please see the SPIDR/AMIE page. The features that are not available are listed in the Development Notes section on the page associated with each data product. A more complete list of pending projects is listed in the Active Projects section.

About ViRBO

ViRBO (Virtual Radiation Belt Observatory) is one of the domain-specific virtual observatories that began operations in Fall, 2006 and is funded under the NASA Heliophysics Data Environment program. ViRBO provides access to data products and services related to Earth's radiation belt. As part of this project, we have developed or extended a number of existing software codebases. These codebases have cross-VxO uses, and we are developing them to be freely re-usable by data providers and other virtual observatories.

• Autoplot - Visualize many space science data resources.
• VxOware - The metadata search and edit engine that ViRBO uses.
• timeseries.org - A fast time series server of remote data sets.

2 News

Old (and searchable) news items are available at http://virbo.org/meta/catalogue.do?source=News

If you have a news item, please send it to http://groups.google.com/group/virbo. If you have write permission, you may add it directly to one of the sections at http://virbo.org/meta/catalogue.do?source=News.

For more information on keeping up-to-date, see this document: [1].

3 Data

Use the links below to access and view data. The inventory links are given when the data are accessible through ViRBO and can be used to see the time intervals when data are available. Data sets with Inventory links are available as merged files (all data in a single file, see Notes#Merged_files for help with these files); subsetting will eventually be available through the ViRBO API (in alpha testing). Other data sets are available in their original file formats only. The metadata for these data sets are stored at ViRBO's metadata site, http://virbo.org/meta. See the Active Projects section for information about data products and services that we are working on. ViRBO's ftp site is ftp://virbo.org.

4 Resources

• Radiation Belt Science Resources
• Radiation Belt Software Resources
• General Virtual Observatory Resources

5 Active Projects

These are some of the projects we are working on (or planning to work on).

Metadata

• Verification and review of all metadata.

Services

Near-term:

• Develop a service and data set that provides L and L* for common satellites.
• Implement a service that performs orbit calculations on AE-8 and AP-8 models. Implement a service that does the same for AE-9 and AP-9 models
• Add L-sort plots to browse products

Long-term:

• Develop a service that simplifies data assimilation for radiation belt models.
• Develop a service that "flies" a real or notional spacecraft through a 4-D environment (e.g., the output of a data assimilation or simulation). In this use case, it's often necessary to time shift the orbit or the simulation to ensure they overlap, which requires additional calculation.
• A principal component (PC) calculator and plotter. Given a 4-D data cube, compute and plot the 3-D PCs, and also plot the time series of PC amplitudes. Similar to computing the boundary normal or minimum variance coordinates. The algorithms are simple, although they do invoke eigenvalue/eigenvector factorization (which is widely available). The results would be stored as a new data product.

Data

Near-term:

• HEO 1 and 3 - Make available as browse product and put in CDF
• OV1-19 and OV3-3 - Make available as browse product and put in CDF
• S33 - Make available as browse product and put in CDF
• SCATHA – Make available as browse product and put in CDF
• CRRESS – Make available as browse product and put in CDF
• GOES < 12 Develop or obtain PRBEM-formatted data
• SYM-H and ASYM-H geomagnetic indices – complete metadata
• LANL_1989_046 – Make available as interactive browse product
• LANL_1991_080 - Make available as interactive browse product
• LANL_LANL_01A - Make available as interactive browse product
• Polar - Make available as interactive browse product
• SAMPEX - Make available as interactive browse product and in CDF

Other data we are looking into:

• TWINS ES – Metadata work
• SAMPEX post-mission
• Full resolution NOAA-14- data – Conversion to CDF and metadata work
• THEMIS-SSD – Metadata and implementation and make available as a browse product
• AFRL DSX – Metadata and make available as a browse product
• International Space Station dosimeter data
• DEMETER
• Orsted
• CHAMP
• ROSAT
• TOPEX
• Any data not on the above list but listed here: http://www.ukssdc.ac.uk/sedat/datasets.html

Tools

Metadata services

• Documentation of the metadata API [2]
• Combining metadata management tools (VxOware, SPASE editor, SPASE-QL tools, etc.)

Data Services

We are developing a high performance data server that allows fast filtering and subsetting - see http://timeseries.org. At present our subsetting option is very limited and we just give access to all data associated with a data set in a single merged file.

• Text output: ASCII output of data (near term)
• Other output: A data query will result in a MATLAB or IDL script that interfaces with our server. Just cut-and-paste the script into your session, and the script pulls the data into your IDL or MATLAB workspace.
• Constraint expressions: We are developing a service that allows the user to subset data on the server. For example, if you wanted to return ASCII data for a spacecraft's location only when when B/Bo was less than 0.1, you would enter a URL like

  http://virbo.org/data/DATASETNAME/?constraint=B/Bo<0.1&return=X,Y,Z&output=ascii

• Documentation of the data API

Visualization

• Interactive plotting in the browser. See http://autoplot.org/applet_guide for a demo
• Multiple panel plotting of data sets that span different missions

6 FAQ

What is a Virtual Observatory? From http://hpde.gsfc.nasa.gov/VO_Framework_7_Jan_05.html

In addition, we think that a virtual observatory should work with their community to

• Identify and allow community access to new instrument data, model code and output, movies, tools, etc. available. More and more individuals are creating specialized data sets or tools (i.e., event lists, filtered data, etc.). They need to work with their VO to identify ways in which their data can be made available to the greater data environment (besides just posting a text file or tarball on their web page).
• Improve metadata and make metadata generation for new data products easier.

Why does ViRBO host files? The “small box” Virtual Observatory concept says that a virtual observatory should only provide services for data in remote locations. Ultimately, however, our objective is to make doing radiation belt science easier.

For small data sets, it is more efficient and reliable to serve data from ViRBO’s server, especially when we want to do transforms or filtering of the data or combine data from multiple locations. Ideally there would be a service that provided our required speed and reliability and ViRBO would connect to this service. In fact, we are developing such a service (see http://timeseries.org). Eventually this service will be separated from ViRBO.

Another reason we host files is as a service to the community. Many of the data sets are from government labs. It is much easier for them to expose their data from ViRBO than to set up a ftp site of their own. Eventually these data sets will be migrated to a data center that specializes in long-term hosting and maintenance of data.

What is the “small box” concept?

Figure 1 The “small box” Virtual Observatory concept says that a virtual observatory should only provide services for data in remote locations.

The “small box” Virtual Observatory concept says that a virtual observatory should only provide services for data in remote locations, as shown in Figure 1 from [3].

In the first three years of operations, many virtual observatories have been involved in activities that fall outside of the “small box”. This usually happens when a service they needed for their community did not exist, so they had to create it themselves.

What is ViRBO’s long-term plan? Most of the NASA Virtual Observatories were funded under 3-year proposals, and this period is ending in 2009. The Virtual Observatories are a component of the Heliophysics Data Environment (HPDE), which is undergoing Senior Review in Summer 2009. The proposed plan for the Virtual Observatories is to continue operations and services normally. Over the next year, ViRBO will be (1) spinning off a number of its non—VO activities into separate projects that provide cross-cutting services to VOs, and (2) focusing more on VO—type projects.