LRIT Testing at NOAA/CO-OPS

STIWG Oct 2011

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CO-OPS operates a DOMSAT system at its two regional offices(Seattle WA and Chesapeake VA)

Each Systems stores up to 6 months of data.

Data from these systems are used for: CO-OPS data bases in Silver Spring MD Testing of systems before deployment Testing of installed systems( new deployments and troubleshooting) Open to other users

Data base queries the system every two minutes.

CO-OPS installed a LRIT system at the Chesapeake office June 2011 and a system in Seattle in September 2011

Both LRIT system are working but not accessible to outside connections

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Compare DOMSAT to LRIT DOMSAT LRITLatency Minimal. DCP messages are Several seconds may be added as sent individually as they arrive messages are aggregated into files and depending on the priority scheme by NOAA

Footprint Continental US GOES East and West footprint. If you can transmit to GOES you should be able to receive LRIT data

Content DCS data DCS data, GOES images, EMWIN

Hardware 1.8 m dish, limited receiver 1.2 m dish, receivers from vendors number of vendors

Software LRGS (sutron) For DCS LRGS (sutron) For GOES images provided by the receiver vendor

Cost Equipment $ 25k $ 25k (Fully installed by Vendor) Usage ~ 75k ( shared ) Free

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Cons

Increased data latencyDouble single point of failureUnknown outage rateAdditional data hops/nodes

Pros NOAA supported productNo cost Hemispheric coverageMultiple productsSmall dish receiver

LRIT Pros and Cons

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Test Plan

Phase 1 - LRIT Data Primary TestsUse existing capabilities to conduct tests, few resources. ObjectivesThe objective of these tests are to: a) familiarize personnel with the new LRIT systems, b) conduct a cursory inspection of the data stream, which will also be used to assist with refinement of subsequent testing, c) initialize the test documentation process, d) provide initial assurance that system configuration is nominal and data streams are ready for Phase 2 testing, e) determine and document changes required to CO-OPS’ data ingestion and processing standards.  Requirements As mentioned above, these simple tests require DOMSAT and LRIT receivers that are not supplemented by data accessed via the internet. Personnel already tasked with system acceptance and inspection, and others as directed, can conduct these tests without substantial development of test tools. The tests can be conducted using data sets that already exist or can be readily created.

Test DescriptionsTest 1A – Select several PIDS and search for all expected data over several daysTest 1B – Compare Domsat and LRIT like files to see that file sizes are similarTest 1C – Compare LRIT file creation time stamps with DADDS reception time stamps Test 1D – Spot check comparisons of Chesapeake LRIT and Seattle LRIT data sets.

 

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Phase 2 - LRIT Data Integrity and Latency Tests

The tests described for Phase 2 will require dedicated resources to develop test tools. As the utilities are developed to inspect data dropouts, longer outages, and data latencies, they will be considered for further development to be used operationally as real-time monitoring tools. ObjectivesCreate tests and generate results that can be used to evaluate the reliability and timeliness of LRIT in comparison to DOMSAT.  Requirements Database management and evaluation tools that can calculate latency statistics for groups of PIDS.

Test Descriptions2A – Quantify data latency for some/many/all? CO-OPS PIDS. Look for latency patterns that correlate with time of transmission.2B – Identify and quantify data gaps and compare to DOMSAT

 

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Phase 3 - LRIT System Stress Tests

These tests may require new development but many can be carried out with existing resources. They are designed to determine how robust the LRIT system is in the face typical, extreme, and outlandish situations so that system expectations can be better understood. ObjectivesPhase 3 objectives are to attempt to determine the limits of LRIT and contrast them to those of DOMSAT.  Requirements Phase 3 will use the tools created to Phase 2 to evaluate the anomalous conditions either created or fortuitously encountered.

Test Descriptions3A – Rain fade3B – Physical obstruction of antenna – step ladders, birds, 3C – Antenna misalignment sensitivity 3D – Local RF interference – introduce common RF sources in the vicinity of the antenna

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Results So FarLimited, Contract expired June. New contract awarded end of September. Testing will start by the end of October

FAILURE 2011/05/15-20:20:12 LritRecv:3 Timed out -- No data received in more than 120 sec.

FAILURE 2011/05/15-20:21:13 LrgsMain:1 LRGS Timeout: No data in 180 seconds.

INFO    2011/05/16-02:48:14 LritRecv File D:\Dartcom\Data\XRIT\Raw\pL-11136001651-B.dcs failed checkLength, not completed