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| CommuniteE-Letter | Volume III, Number 5, September 2006 |
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| Powered by Unidata |
by John Meyers, Museum of Science in Boston
WeatherWise, the Museum of Science's impressive weather exhibit, is an ambitious undertaking that successfully uses GEMPAK as a visualization and analysis tool, and data delivered by Unidata's LDM/IDD delivery system. — Editor
Funded by a grant from the National Science Foundation, the Museum of Science's WeatherWise exhibit is teaching over 1.5 million visitors per year about short-term forecasting, or nowcasting. The museum's unique web site will "extend the power of the exhibit, by providing the public with live weather data and background information to make their own nowcasts."
To accomplish its mission, the museum is a Unidata IDD participant, using a feed that includes public products, models, satellite, and Level II radar. The museum generates an hourly high resolution analysis that covers the state and a little of the surrounding area, using the University of Oklahoma's Center for Analysis and Prediction of Storms (CAPS) ADAS suite, and IDD data along with mesonet data obtained on a second feed direct from NOAA's Global Systems Division (GSD). In addition to ADAS, the museum also uses NOAA's National Severe Storms Laboratory (NSSL) Warning decision Support System (WDSS) suite to generate extremely clean quality-controlled radar composites for their area off of the Unidata level II radar data, and McIDAS to remap satellite data. The whole of this output is then processed by a series of Perl scripts that use GEMPAK to plot the data as well as to extract pertinent pieces of point data. This data is made available to the web front-end as a series of transparent images with corresponding XML files to describe the data. These are used by a Macromedia Flash-based web site (currently under development) that walks the user through the process of creating and verifying a Nowcast for the next 3 hours. (View a screen shot of web site.) Using this system, the museum is, for instance, able to identify features of note using GEMPAK HILO parameters and then instruct the Flash code to point at the target by passing the output as X,Y coordinates within the XML. The web site will soon be available to the public and will be featured on a kiosk in the exhibit.
In addition to the web site, all of the above data is also hosted on the museum's own THREDDS server and archived on a dedicated 3-terabyte array for local use in IDV. A few adventurous souls in the Programs department are exploring the use of the IDV (and NSSL's WDSS client) for public presentations using both realtime and/or locally archived data.
Benjamin Franklin once said "some people are weatherwise, but most are otherwise." The Museum of Science's goal is to increase the numbers in the former group thereby reducing the numbers in the latter. The exhibit contains components enough to fascinate and intrigue users of all ages. Unidata is delighted to be some part of its success. — Editor
Visit the Museum of Science on-line.
by William Gallus Jr and Daryl Herzmann, Iowa State University
The recent few years have seen an explosion with the need and use of environmental data provided via web services and standard formats to Geographic Information Systems (GIS). Unidata has been a pioneer in developing software and stimulating its community to meet this growing need. To that end, the Unidata Equipment Awards program provided funding to the Iowa Environmental Mesonet (IEM) of Iowa State University to increase its capacity to serve Unidata-provided datasets to the expanding GIS user base within the Unidata Community.
Hardware Purchased
Using funds provided by the Unidata Equipment Award and supplemental local funds, the IEM was able to build a mostly fault tolerant and scalable infrastructure to support the mass dissemination of GIS products and web services. Specifically, two powerful Dell PowerEdge 2850 servers along with nearly one terabyte of fast disk space were purchased with the Unidata award. After some bureaucratic fun, these systems were placed in production on November 29, 2005.
These new servers were configured as participants in a Linux Virtual Server (LVS) cluster. The figure at the left shows the current topology of the cluster, with the Unidata funds providing the "LDM Processor" and "Spatial Database" components. An LVS cluster provides a software based solution to do high availability and load balanced computing. Two "director" nodes create a redundant virtual presence providing services by brokering traffic between external clients and cluster internal services. These services include a Local Data Manager (LDM) instance, Spatial database, and web servers.
Delivering Unidata Datasets to GIS
The project proposal outlined a number of Unidata provided datasets that would be made accessible via web services and GIS formats. During the past year, some of these datasets are now being provided in GIS formats/services by institutions such as the National Weather Service (NWS). The NWS should be commended for efforts such as their RIDGE RADAR data display system and the Precipitation Analysis website which provide the GIS community with operationally supported datasets.
Thanks to the Unidata award, the IEM is now providing these services and data files for the communities use.
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CONUS NEXRAD base reflectivity compositesMany of These Links Have Special Functionality
Please check the information in parentheses following these links.
Availability: LDM/IDD, OGC WMS-T (for access via Web Map Service (WMS) clients), HTTP GeoTiff (best viewed with GIS Client, though viewable with browser)
Notes: This dataset is by far the most requested and the most widely used dataset the IEM provides. It is produced by using the 'nex2img' GEMPAK program written by the Unidata Program Center. Nationwide ~1 km resolution products are generated every 5 minutes. The equipment award allowed the IEM to provide a WMS that supports the time specification (WMS-T). This feature exposes our entire 5 minute interval archive dating back to 2003 to WMS-T aware GIS clients! - NWS watch/warning products
Availability: LDM/IDD, OGC WFS (view with a WFS client), HTTP Shapefile (view with GIS client), XMPP Jabber
Notes: Utilizing the robust and extremely fast LDM/IDD infrastructure provided by Unidata, the IEM wrote a number of decoders to ingest various NWS issued products into a spatial database (PostGIS). This software will be eventually released to the Unidata community under an Open Source license. Organizations interested in beta-testing this software should contact Daryl Herzmann. - GOES satellite composites
Availability: OGC WMS (view with a WMS client), HTTP GeoTiff (best viewed with GIS Client, though viewable with browser)
Notes: GOES East and West, IR and VIS imagery are available. CONUS composites are also generated using a GDAL utility. An archive of these products will be exposed via a WMS-T instance later this summer. - "Stage 4" NWS precipitation estimates
Availability: NWS Precipitation Analysis
Notes: The NWS has provided this wonderful service, so there was no need for the IEM to duplicate this effort. In the near future, the IEM will provide OGC WMS, WFS, and WCS services of this dataset.
Here is an example interface utilizing the WMS-T NEXRAD service. The interface code is a part of the OpenLayers toolkit. The default time display shows Hurricane Katrina making landfall.
Summary
The Unidata Equipment Award provided funding necessary to increase the capacity of the IEM to provide datasets to the GIS community. Since the installation, the IEM web farm is now handling four times the number of web hits than when it was previously at full capacity last fall. The infrastructure in place should allow another 8 fold increase in internet traffic before more substantial resources would need to be purchased.
As always, the IEM continues to work with other members of the Unidata community, NWS, and private/public sector to increase the use of these services and adoption of similar technologies. Please do not hesitate to contact Daryl Herzmann if you have any questions or suggestions.
Early August brought changes to the Unidata Program Center. We welcomed Terry Mitchell as the new program administrator and bade a (fond and fun) farewell to Joanne Graham.
Terry came to Unidata in early August with an impressive background that will serve him well. Most recently Terry served in UCAR's Finance and Administration group where he was a project accountant whose responsibilities included contract management for Unidata. Since he was already familiar with Unidata's budgets and finances, he has a solid knowledge base to work from. His areas of expertise include: financial analysis, project management, cost analysis, client portfolio management, reporting, cash management, general accounting, contract administration, and budgeting and forecasting.
Prior to joining UCAR F&A in 2002, Terry worked for the Nelnet Corporation, an Aurora based firm, for nearly 10 years. His educational background includes a Bachelor's degree in Organizational Management from the University of Colorado Boulder, and an MBA in Finance, from CU Denver.
A native of Colorado Springs, Terry water-skis all summer long (weather permitting), captains his volleyball team as part of the Denver league in the fall and spring, and plays on the Denver Area Softball League as well. In any remaining time, he hikes and bikes. He currently lives in Westminster with his partner, Tony. They have neither kids nor pets (unless you count goldfish in the backyard pond) but they just started the adoption process so hopefully their domestic count will increase sometime next year!
The Program Center said farewell to Joanne Graham earlier in the summer when she stepped out of her Unidata position and made the move to the NCAR/ESSL/Climate as the Global Dynamics division's new administrator.
Terry steps into a program that is stable, productive, and looking forward to creating and submitting its next five-year funding proposal. There's very little doubt that he will contribute his ideas and experience to its production.
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2006 Training Workshop Space is still available in the 2006 Training Workshop for Unidata Software. The workshop features old favorites such as McIDAS, GEMPAK, and LDM; our newest visualization package, the IDV; and three sessions newly developed for 2006—netCDF for Developers, netCDF Java, and THREDDS Data Server Administration. The workshop runs from October 23 – November 12, 2006 at the Unidata Program Center in Boulder, Colorado. The cost to attend the workshop is $50 per session. For more details on the workshop or to register, please visit our web page.
