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The Evolution and Development of the United States NOAA National Weather Service Universal Radiosonde Replacement System. TECO 2005 World Meteorological Organization Bucharest, Romania. History of NWS 50-Year Old Radiosonde System. One radiosonde provider until 1986 Systems Upgrades
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The Evolution and Development of the United States NOAA National Weather Service Universal Radiosonde Replacement System TECO 2005 World Meteorological Organization Bucharest, Romania
History of NWS 50-Year Old Radiosonde System • One radiosonde provider until 1986 • Systems Upgrades • Minicomputer-based system to Microcomputer Automatic Radiotheodolite (MICROART) • Introduced Automatic Radiotheodolite Interface Card (ARTIC) • ARTIC converts radiosonde analog signals to meteorological units
History of Vendor Interface with Legacy System after ARTIC Introduction • VIZ continued as radiosondes provider • Space Data Division successfully interfaced radiosondes and became supplier in 1987. • Vaisala interfaced NWS system via their decoder in 1985. • Vaisala awarded contract in early 90s • Substituted Vaisala SPU-11 decoder for ARTIC • Modified RS80-56-H radiosonde
Advantage of Multiple Radiosonde Provider Compatibility with Generic System • Lower radiosonde cost • Insurance against supply shortfalls • Stimulates radiosonde improvement to maintain competitive edge • Avoids replacement of entire system
Network Replacement Considerations and Realities • End-of-system life • Winter RDF winds loss without transponder adjunct • Multiple radiosonde providers • Avoidance of vendor driven program changes • Loss of Omega systems • Loss of vendors, ground systems and radiosondes • Space Data Division discontinued producing radiosondes and ground trackers • Vaisala buyout of Air Inc and non-support of product line • Vaisala programmed discontinuation of RS80 Series radiosonde and selected ground receivers in 2005 • Anticipated loss of Loran-C • Loss of OMEGA NAVAID system
Commercial Systems vs System Development • Technology Management Corporation evaluated 5-systems against NWS requirements • Commercial systems did not support multiple vendor radiosondes interface with generic ground receiver and software. • Ground receivers did not support 250 Km range between radiosonde and ground receiver
NCAR NEXUS Prototype Development • Requirement • Multiple vendors support • 403 and 1680 MHz radiosondes • Loran-C and OMEGA based Windfinding • One person operation • Semi-automated balloon launcher
NEXUS Findings • Not completely open architecture • Required vendor specific decoders • Minimal impact to system hardware and software with of new radiosondes • Broad-band receiver maximized different use but enabled interference • Obsolescence of Omega and projected phase-out of Loran-C • Demonstrated generic system approach
Radiosonde Replacement System • Telemetry Receiver System • Radiosonde Signal Processing System • Software and Workstation • Surface Observation Instrumentation System • 1680 MHz GPS radiosonde
NOAA NWS Radiosonde Replacement System • System • GPS tracking antenna • 1680 MHz GPS radiosonde • New workstation and software • Circular polarized radiosonde antenna • Selectable narrow band frequency • Requirements • Reduced radiofrequency spectrum • Increased data availability and accuracy • High resolution data for users
Radiosonde Replacement System • Telemetry Receiving System available • 1680 MHz GPS radiosondes • Intermet qualified • Sippican qualified and awarded contract • Software undergoing OT&E • Additional radiosonde qualification underway • Sippican • Intermet • Vaisala
Commercial Universal System • NWS supported 10-station Caribbean network uses • NWS specified SPS • IMS 1500 tracker and computer software • Sippican B2 radiosondes • India Installing IMS 1500 Universal System • WMO GCOS IMS1600 Universal System in Tanzania • Integrates Sippican Mark II pressure radiosonde • Signal processing system
Universal System Issues • Radiosonde providers may not wish to collaborate with Universal System providers • Small market vs large market • Proprietary SPS transfer equations, and software utilities utilities to make pressure adjustments and supply radiation corrections • Make radiosonde bandwidth and power output consistent with ground receiver bandwidth and antenna gain • Integration of Universal system needs to be fully tested before implementation
Conclusions • Use of 1680 MHz RDF tracker for GPS radiosondes is feasible in areas where 403 MHz band is crowded • Universal system viable with less expensive RDF radiosondes in areas such as the Tropics and Sub-tropics where limiting wind angles remain above 13-17 degrees • Universal system enables radiosonde competiton