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A Time of Transition for EMWIN

A Time of Transition for EMWIN. OVERVIEW. The GOES satellites Summary of inherent EMWIN advantages What must change? When could changes occur? Getting ready – brief chronology Transition objectives System design & specifications Prototype receiver design & construction Field test results

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A Time of Transition for EMWIN

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  1. A Time of Transition for EMWIN William A. Johnson

  2. OVERVIEW • The GOES satellites • Summary of inherent EMWIN advantages • What must change? • When could changes occur? • Getting ready – brief chronology • Transition objectives • System design & specifications • Prototype receiver design & construction • Field test results • Transition planning • Current international activities • For more information • Vendor input needed • Conclusion William A. Johnson

  3. The NOAA GOES Satellites • The mission of the Geostationary Operational Environmental Satellites (GOES) • The GOES program goes back to 1975 with the launch of the first of the GOES A-F series of satellites. • Many of the sub-systems aboard the GOES satellites produce specialized weather information of a technical nature useful primarily to scientists, especially meteorologists and climatologists • The important inclusion of a communications transponder as one of the subsystems • Essentially for real-time weather facsimile information (WEFAX); now replaced by the Low Rate Information Transmission (LRIT) system. • The spare bandwidth on the transponder allowed the inclusion of a narrow band EMWIN channel after the advent of the GOES I/M series in 1994 William A. Johnson

  4. The NOAA GOES Satellites, cont’d • Bandwidth comparison of the communications transponders for the GOES-I/M Generation with the GOES N/P Generation • GOES I/M: 1 mHz bandwidth for both LRIT and EMWIN • GOES N/P: • Separate transponders for LRIT and EMWIN. • EMWIN transponder bandwidth is 50 kHz William A. Johnson

  5. Summary of Inherent EMWIN Advantages • No recurring cost for satellite service • Large GOES satellite footprint - full CONUS coverage • Use of L band - invulnerable to precipitation fading • Redundant GOES satellite coverage for CONUS • Extremely valuable to island nations • Essential service available during times of fiber or wire outage • Existing base of government & private users • Watch & warning dissemination in < 1 minute • High portability of receiver with small antenna & use of laptop William A. Johnson

  6. What must change? • With the advent of GOES-N/P satellite generation • Broadcast power must be reduced to comply with the International Telecommunication Union (ITU) power limits: • From: 51.0 dBmi (minimum EIRP) • To: 44.8 dBmi (minimum EIRP) • Frequency must change: • From: 1690.725 MHz • To: 1692.700 MHz William A. Johnson

  7. When Could Changes Occur? • 2006 - 2011 • GOES-N launch • May 24, 2006 • GOES-N Operational • First broadcast of new EMWIN-N service depends upon: • Fuel usage for both GOES 11 or 12 • Subsystem health • Demand for new technology • Fuel exhaust date for existing GOES constellation is 2011 • GOES-O launch • As early as April 2008 William A. Johnson

  8. Transition Objectives • NWS & NESDIS teamwork • Retain inherent EMWIN advantages • Minimize cost to user for transition • Any new receiver design must work on both current and new GOES system • Listen to users & vendors and keep them informed • Establish overall system design specifications • Design, construct & test a proof-of-concept prototype receiver • Release schematics and operating software to industry for vendor guidance • Prepare and maintain a transition plan William A. Johnson

  9. Getting Ready – Some Chronology Highlights • NWS /NESDIS task team formed – late 2003 • With AVTEC as NESDIS contractor • User-vendor conference – April 2004 • Presented a 9.6 kbps version prototype • Users & vendors wanted increased data rate and lowest possible cost • Goals for transition project changed to incorporate user/vendor requests – June, 2004 • GOES-N launch – May 2006 • Successful test of prototype via GOES-N – Sept. 2006 • Request for Information issued on FedBizOps – Nov. 2006 William A. Johnson

  10. System Design & Specifications • Complete documentation available on EMWIN website: • http://www.nws.noaa.gov/emwin/index.htm • EMWIN-N Signal specification includes data on: • Compliance with Consultative Committee for Space Data Systems (CCSDS) • Downlink frequency & modulation • User data rate • Radio frequency symbol rate • Pulse shape filter • Satellite transmit Equivalent Isotropically Radiated Power (EIRP) • Forward Error Correction Code (FEC) • Block Channel Access Data Unit (CADU) size • Attached sync marker • Randomization • Link budget William A. Johnson

  11. Prototype Receiver Design Concepts & Goals • Minimum dish antenna size will be retained at one meter – • Provide an operating margin of at least 5.5 dB • Use of Offset Quadrature Phase Shift Keying (OQPSK) modulation and forward error correction to compensate for lower power level • Software-defined radio concepts to be used for demodulation and decoding functions • Hardware implementation schemes for intermediate frequency conversion and analog/digital conversion • Must be capable of receiving either existing GOES I/M signal or new GOES N/P signal William A. Johnson

  12. Offset Quadrature Phase Shift Keying • A version ofphase-shift keying modulation which uses 4 different phase values of the phase to transmit. • It is also known as “'Staggered quadrature phase-shift keying (SQPSK). • Regular quadrature phase-shift keying (QPSK) has the disadvantage of allowing a possible 180 degree phase shift for certain bit combinations resulting in undesirable amplitude fluctuations in the signal. • By off-setting the timing of the odd and even bits in the data stream the phase shift of the resultant output stream will be limited to 90 degrees yielding less amplitude fluctuations. William A. Johnson

  13. Software Defined Radio • "In a software-defined radio, functions that were formerly carried out solely in hardware, such as the generation of the transmitted signal and the tuning and detection of the received radio signal, are performed by software that controls high-speed signal processors.“ • FCC Definition William A. Johnson

  14. The 19.2 kbps Prototype William A. Johnson

  15. IF Adapter Functions • Converts signal from Low Noise Block (LNB) at approximately 137.225 MHz down to audio frequencies • Provide gain • Make output compatible with standard stereo sound card interface • Provide In-phase (I) & Quadrature (Q) inputs to sound card • Power source for L-band downconverter • Crystal change needed to move from current EMWIN broadcast to new EMWIN broadcast William A. Johnson

  16. Intermediate Frequency Adapter William A. Johnson

  17. Sound Card • Stereo sound card functions as a low-cost, readily available analog-digital converter • Interface to IF adapter to accept I & Q inputs for digital sampling • Prototype solution expected to work with most available newer PC sound cards • Minimum sampling rate must be at least 44.1 kHz, preferably 48 kHz • Laptop installations will normally require an external card William A. Johnson

  18. Prototype Minimum PC Requirements • 350 MHz Pentium II, or faster • Stereo sound card capable of simultaneous sampling at 48 KHz • Windows 2000, NT or XP operating system • Installed Internet Protocol stack • Two RS-232 ports • > 160 MB memory • EMWIN decoder/demodulator software • EMWIN display software William A. Johnson

  19. The Prototype Software Demodulator Components William A. Johnson

  20. Software Availability • Down-loadable software (dynamic link libraries or DLL) available on EMWIN website: • http://www.nws.noaa.gov/emwin/index.htm William A. Johnson

  21. Field Test Results for Prototype • Testing via GOES-N at NOAA Wallops Command & Data Acquisition site in Sept. 2006 • Copy of final test report (available) shows receive system margin of 5.5 dB William A. Johnson

  22. Field Test Results William A. Johnson

  23. A Possible Transition Scenario William A. Johnson

  24. 135W • 75W GOES 11 GOES N GOES 10 (WEST) GOES 12 (EAST) Mid 2006 – Late 2006 1690.725 DFSK 9.6kbps 1690.725 DFSK 9.6kbps GOES-N Uplink processor 1692.700 Offset QPSK 19.2kbps EMWIN - I • Approx. 30 days after launch , GOES-N 19.2 testing begins (Sept.2006) • GOES 10 nearly out of fuel, plan is for GOES 10 to be replaced by GOES 11 (about June 28,2006) • GOES 10 drifted to 60 degrees W for possible use by Argentina or Brazil (unofficial) William A. Johnson

  25. GOES N (EAST) GOES 11 (WEST) EMWIN N Cutover GOES East GOES 12 (EAST) 1690.725 DFSK 9.6kbps 1690.725 DFSK 9.6kbps 1692.700 Offset QPSK 19.2 kbps EMWIN -N EMWIN - I • Cutover date is sometime between 2007 and 2011 William A. Johnson • GOES N replaces GOES 12

  26. GOES 11 (WEST) GOES N (EAST) 1690.725 MHz DFSK 1692.700 Offset QPSK 19.2 FEC WALLOPS EMWIN -I WALLOPS EMWIN - N Sometime between 2007 - 2011 operational scenario William A. Johnson

  27. GOES N (EAST) GOES O 200? to 2011 Final cutover (WEST) 1690.725 dfsk EMWIN -I 1692.700 MHz EMWIN -N • 200? To 2011 GOES O replaces GOES 11 • Final Cutover to EMWIN N William A. Johnson

  28. CONUS users (most) not ready to transition can re-point to GOES west (EMWIN-I) until latest date 2011 William A. Johnson

  29. For More Information • Updates posted on the EMWIN website - http://www.nws.noaa.gov/emwin/index.htm • Sign up for the EMWIN mailing list, if not already on it • EMWIN user groups on Yahoo – tech.groups.yahoo.com/group/emwin users/ • Local outreach programs • Via Warning Coordination Meteorologists in NWS Weather Forecast Offices • Special conferences, such as • Southeast U.S. EMWIN Workshop at Huntsville, AL, 2004 and 2006 William A. Johnson

  30. International ActivitiesThird Border Initiative (TBI) • A 2001 initiative by President Bush to aid the Caribbean island nations via a broad package of programs. • One of these programs will increase funding for Disaster Preparedness and Mitigation efforts to shield critical commercial and environmental infrastructure from natural disasters, such as hurricanes. • NWS, in consort with the NOAA International Affairs Office, will set up an EMWIN training program and provide EMWIN-I receiving systems to five island nations William A. Johnson

  31. Current International ActivitiesGOES-10 Move • NOAA is repositioning GOES-10 satellite to 60 degrees West to improve coverage over South America • Continent will benefit from emerging Global Earth Observation Network • Shift will help protect lives and property in North, Central and South America by significantly improving satellite detection of natural hazards. • Will further strengthen the WMO's World Weather Watch Global Observing System. • LRIT/EMWIN transponder not yet assigned for service in its new position William A. Johnson

  32. Notes to Vendors • Proof-of-concept prototype must not be interpreted as a constraint on any workable implementation, whether via hardware or software • Some possible concerns: • Answers to questions about the prototype design? • A satellite-based test bed? • Grants to aid disadvantaged areas to purchase systems? • Other? William A. Johnson

  33. Are there any questions? William A. Johnson

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