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Water Vapor Sensing System (WVSS-II)

Water Vapor Sensing System (WVSS-II). Tunable Diode Laser Technology supporting AMDAR Water Vapor Observation Applications. Bryce Ford Nov 9, 2011. Optical Sample Cell. Gas Sample. Window. Laser. Mirror. Detector. Brief History of Tunable Diode Laser (TDL) Spectroscopy.

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Water Vapor Sensing System (WVSS-II)

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  1. Water Vapor Sensing System(WVSS-II) Tunable Diode Laser Technology supporting AMDAR Water Vapor Observation Applications Bryce Ford Nov 9, 2011

  2. Optical Sample Cell Gas Sample Window Laser Mirror Detector Brief History of Tunable Diode Laser (TDL) Spectroscopy • TDL was developed and refined by NASA at Caltech’s Jet Propulsion Lab over a 20 year period • Original systems developed and flown on aircraft and weather balloons for Atmospheric Research • The technology achieved space flight qualification and was launched on the 1999 Mars Polar Lander Spacecraft • Today TDL technology is considered mature and reliable and is in use for many applications • Basic TDL Absorption Spectroscopy (TDLAS) concept: Concentration = (How much light is absorbed (energy) thru the sample cell) (Absorption Coefficient for a species) x (its path length)

  3. WVSS-II Developed to Support AMDAR • Water Vapor Sensing System, WVSS-II, uses TDLAS to continuously measure atmospheric Water Vapor concentrations during flight • WVSS-II was specifically developed to support the needs for an AMDAR Water Vapor sensor, with the high reliability and low maintenance requirement for use in commercial aviation • It has undergone significant Engineering testing and Scientific evaluation over the last 7 years to arrive at the current configuration • Unique SpectraSensors design features provide very stable operation over long periods of time with no regular maintenance • The SpectraSensors technology is not effected by contaminants that impact many other TDL implementations

  4. WVSS-II Primary Components • The Primary Components of WVSS-II • System Electronics Box (SEB • Air Sampler (UCAR Patented) • Inlet and Outlet hoses • Power and Data Communications DB-26 for RS-232 Data Output in Research and Test Configurations System Electronics Box (SEB) Air Sampler Hoses Standard Aircraft Power/Data Connector

  5. FWD Aircraft Skin Outlet Hose, Non-Heated SEB SEB Hoses Inlet Hose, Heated Air Sampler Inside view of Air Sampler Typical Installation – Internal View • Typical Interior Installation Configuration for WVSS-II

  6. Typical Installation – External View • External View of Air Sampler Installation Air Sampler Installation on a 737-300 Expanded View of the Air Sampler

  7. Interior of WVSS–II SEB • Interior view of the WVSS-II SEB Spectrometer Optical Cell Main Processor Board Note: There are no user maintainable items inside the SEB

  8. Optics Of The WVSS Analyzer • Spectrometer Optical Cell Inside the SEB Laser Mirror Optical Cell Hose Connections Detector Laser Beam

  9. WVSS-II Air Flow • Diagram of Air Flow through the WVSS-II Sample Cell Inside SEB

  10. Aircraft Operation and Maintenance of WVSS-II • Operation of the WVSS-II is 100% Automatic • No adjustments or settings necessary by airline partners • Data is transmitted from the SEB to the ACMU continuously when system is in operation • Transmission of data via ACARS is independent of WVSS-II operation • No Routine Maintenance Necessary • No consumable components to be exchanged • Sensor maintains calibration for at least 2 years • Air Flow Through the System is Critical • Any obstructions to air flow can be cleared with simple procedures • For aircraft that are on the ground for long periods, it is best to cover the inlet/outlet to avoid nesting by bugs • Long Term Maintenance at Regular Aircraft Heavy Check • Suggested functional/calibration check of SEB every 2 or 3 years at SSI

  11. WVSS-II Performance Characteristics • WVSS-II Performance Characteristics [1]Conversion of Minimum detectable signal from ppmv to g/kg is computed for 200 mb and -57˚ C, a representative atmospheric condition at approximately 40,000 ft Flight Level [2] Conversion of Maximum detectable signal from ppmv to g/kg is computed for 1016 mb and 36˚ C, a representative atmospheric condition at the Surface

  12. Environmental and Power Requirements • Environmental Range (SEB = System Electronics Box) • Power Requirements

  13. 3 Mounting Screws – Each End Physical Specifications • Physical Specs; System Electronics Box • Physical Specs; External Air Sampler* * The Aerial Sampler Patents, U.S. Patent No.s 6,809,648 and 6,997,050, were developed by the University Corporation for Atmospheric Research. The University Corporation for Atmospheric Research Foundation has licensed the Aerial Sampler Technology to SpectraSensors Inc.

  14. Relevant U.S. FAA Certifications • WVSS-II Product Certifications • SpectraSensors Manufacturing and Engineering Facilities Certifications

  15. Corp Headquarters Houston, TX Production and Engineering Development Rancho Cucamonga, CA SpectraSensors Locations Small Business ~80 Employees, with 35 Engineers and Scientists Atmospheric Programs Bethesda, MD (Washington DC Metro Area)

  16. WVSS-II Production at SpectraSensors • SpectraSensors is FAA Certified for Production and Repair of WVSS-II

  17. Examples of Soundings from WVSS-II Equipped Aircraft • Use of WVSS-II Data by Meteorological Operations is no different than traditional sounding data, once processed into standard format

  18. Status of US NWS WVSS-II Network as of September 2011 • 24 Hours of WVSS-II Date from the U.S. NWS Network from 54 Aircraft UPS: 25 SWA: 29 Total: 54 * Data and Visualization courtesy of NOAA ESRL/GSD

  19. Global Implementation Status • WVSS-II Units in Operation by WMO Member NMHS • WVSS-II Units in Operation by Other Users

  20. Potential Future Opportunities Future Opportunities • Potential Expansion to other New Sensors if there is Sufficient Market Demand • Extending Water Vapor Measurements to Lower Concentrations • Other Greenhouse Gases

  21. Starting with Moisture and Moving to OtherGreenhouse Gas Measurements CH4 Methane SF6 Carbon Dioxide N2O Hydrogen Sulfide Sulfur Hexafluoride Nitrous Oxide O3 Ozone Water Vapor Other Greenhouse Gas Measurement Atmospheric Water Vapor (H20) • Drives Much of Our Weather • Source of Our Precipitation • Is a Major Contributor to the Greenhouse Effect • WVSS-II Verified in Operation • Other Greenhouse Gas Measurements can be taken using similar technologies • Requires Different Lasers, Electronics, Measurement Cell, and additional Aircraft Certifications • Can be addressed when Market Demand is Verified Water Moisture Measurement

  22. Thank You! Thank You Gracias Obrigado Bryce L. Ford Vice President of Atmospheric Programs Mobile: +1-202-549-3477 bford@spectrasensors.com SpectraSensors, Inc. 4720 Rosedale Ave Suite #720 Bethesda, MD 20814 www.spectrasensors.com/wvss

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