NEXRAD Level II radar data are now being distributed in a partnership among and the NWS and academia via the Internet2 Abilene network, and the private sector over commodity Internet using Unidata’s Local Data Manager (LDM) technology. The amount of data currently being created nationwide by the WSR-88D network averages about 22 gigabytes per day, compared to about 4.5 GB for the combined Level III products. Creating a system capable of handling the large volume of Level II data as well as managing a network connection to pass all the Internet traffic to Unidata community participants, was a challenge the Texas Mesonet undertook for several reasons.

- We believed there would be benefits to the user community in having immediately available a disk-cached archive of recent radar data. - Texas A&M, one of over 200 University members of the Internet2 consortium, has played an active role in the operations of the Abilene network. Texas is currently engaged in creating a statewide fiber optic network to serve institutions of higher education. This network will interface directly to the Abilene network in at least 2 cities, and will provide high-speed inter-institution connectivity for moving scientific data and model output. Archival and relay of the Level II data falls nicely into the mission of the Lonestar Education and Research Network (LEARN). - We were able to leverage the decreasing costs and complexity of creating large RAID (Redundant Array of Inexpensive Disks) arrays to build a server capable of holding at least 30 days of Level II and Level III data at current data volumes both rapidly and inexpensively.

Upon initiation of the Level II data feed, problems associated with the system's disk array were encountered. Since remote tuning proved cumbersome, the system was relocated to the main Texas A&M campus for software and hardware modifications. There it was determined that the RAID controller we had selected was incapable of maintaining performance under the volume of data we were presenting it. We also identified system cooling problems and a hard disk failure which caused unstable performance.

A series of configuration experiments resulted in significant improvements to our LDM data ingest, relay, and associated processing performance. Working with Unidata, Texas Mesonet reconfigured the system, bigbird.tamu.edu, to use software instead of hardware RAID; reprogrammed the RAID controller to act as a simple IDE controller; removed one defective disk; and reformatted the disk array to support a smaller and yet still ample (1.4 terabyte) volume with better redundant failure tolerance. Adjustments were made to LDM and data processing configurations to improve performance, and possible changes to decoders spawned by the LDM were tracked and evaluated. Since we consider bigbird, declared operational on June 12, 2004, to be a “smoking” success, we are examining the logistics needed in renaming it phoenix in honor of its rebirth.

The Texas Mesonet has also begun creating products associated with the Level II data. Using Unidata’s GEMPAK tools, we have created two web pages for testing, one generating all images on-demand, while another displays images created as the volume scans arrive. We anticipate additional products in the short term using Level II data. Samples of our work can be found at http://gemdata2.tamu.edu/radar/ and http://mesonet.tamu.edu/LevelII.html .

We have built a system that allows us to contribute to the Internet2 distribution of Level II radar data by maintaining an on-demand 30-day cache of all Level II radar data. We have created web pages which focus on delivering Level II static images and image animations, to support the users in the State of Texas. We also support the Amateur Radio community, and its cadre of active SkyWarn participants and storm spotters by providing several Level II radar mosaics for the continental United States. The Texas Mesonet has begun to come of age, providing useful products to the citizens of Texas, and agencies who find these products useful.