LDM and IDD Status Report

Steve Chiswell
Steve Emmerson
Mike Schmidt
Jeff Weber
Tom Yoksas

2004-10-19

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 Status Report

• LDM Versions 6.0.15 and 6.1.0 have been released since the last report.

• Steve Emmerson conducted an LDM training workshop at the NWS Central Region Headquarters as part of the NWS's project to establish a nationwide distribution system for NEXRAD Level II data using the Internet and the LDM. The NWS paid all travel, salary, and benefits. On-site LDM training is not finished. We are waiting on the Eastern and Southern regions to let us know when they would like a site visit for training workshop.

• rtstats has been modified to report statistics in floating point format. The new version, currently being tested at the UPC, will be included in the next LDM release.

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IDD Status Report

• 233 machines at 134 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 is using LDM-6 to move NEXRAD Level II data. LDM-6.0.14 was installed in the initial distributed build. Results of performance monitoring studies being conducted by NOAA personnel (Blanchard) are being shared with the UPC. Information gained is being used to guide code modifications that will be included in future releases.

  The NWS transition from the CRAFT distribution network (built by OU) to their own network that relies on use of Internet2 is proceeding on schedule for completion in the early to mid-October timeframe.

• Unidata has obtained and tested several DVB-S receivers 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. Comparison of performance characteristics of Novra hardware used to receive the DVB-S signals revealed discrepancies in firmware versions among units. Older units have had firmware upgrades to match the units being deployed by the NWS.

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For previous information, please refer to the February 2004 Policy Committee status-report.