LDM and IDD Status Report

Steve Chiswell
Steve Emmerson
Mike Schmidt
Jeff Weber
Tom Yoksas

2004-03-01

Real-time, self-managing data flows -- Unidata will foster and support the existence of real-time data flows that encompass a broad range of Earth-system phenomena, can be accessed with ease by all constituents, and are self managing in respect to changing contents and user needs.

--A goal of Unidata 2008: Shaping the Future of Data Use in the Geosciences

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LDM-6 Status Report

• The LDM has been stable since the last report.

• At the request of the NWS, Steve Emmerson is traveling to national and regional NWS Headquarters in order to conduct training sessions on the LDM system and to vet (i.e., "tune up") their existing LDM networks. This is being done in preparation for the establishment by the NWS of a nationwide distribution system for NEXRAD level II data using the Internet and the LDM. The NWS is paying all relevant travel, salary, and benefits. So far, Steve has visited the National NWS HQ in Silver Spring, MD, and the Western Region NWS HQ in Salt Lake City, UT.

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IDD Status Report

• 166 machines at 100 sites are running LDM-6 and reporting real time statistics. Sites continuing to run LDM-5 are being encouraged to upgrade to LDM-6 as quickly as possible. Unidata staff have remotely installed LDM-6 at many sites to expedite the changeover process.

• Real time LDM statistics can be found in the Real Time IDD Statistics webpage. The topology and data flow information reflects changes in feed requests within a few minutes of changes. Rtstats have proven to be most useful in diagnosing reception problems at sites, especially when universities have implemented restrictions on packets volume in and out of the campus without regard for their user needs.

  In order to correctly guage real-time status of the IDD, it is important for all sites participating to accurately maintain their clocks (easily done through Network Time Protocol software and servers).

• NWS will use LDM-6 to move NEXRAD Level II data. LDM-6.0.14 will be in the initial distributed build.

• Unidata has obtained and tested a DVB-S receiver to prepare for the NWS migration from the current operational broadcast of NOAAPORT data streams to a DVB-S based system. Tests have shown compatibility between the Unidata developed software used to ingest the NOAAPORT data feeds and the DVB-S broadcast stream implemented by the NWS for evaluation.

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For previous information, please refer to the October 2003 Policy Committee status-report.