1. 1 Summary of Global Tropospheric Wind Sounder (GTWS) Technology Roadmap Ken Miller, Mitretek Systems June 23, 2003

2. 2 Agenda Purpose Vital National Need Multi-year Interagency Program Recommendation Status Reference Designs DWL Alternatives Roadmap Summary and Recommendations Acknowledgments

3. 3 Purpose GTWS: Acquire global wind profiles Roadmap: Focus GTWS activities Draft roadmap submitted for NASA and NOAA consideration Based on multi-agency input High level Important unknown factors Resource needs will vary widely depending on approach and rate of technology progress

4. 4 Vital National Need Global winds are the number 1 unmet observational requirement for global weather forecasts (NPOESS IPO) NASA Earth Science Directorate plans include global tropospheric wind observation and assimilation Wind data will support missions of NOAA, NASA, DOD, FAA, FEMA, Department of Homeland Security Benefits to government, industry, and citizens include Weather forecasting Atmospheric and climate studies Transportation Air quality forecasting Shipping Agriculture Construction

5. 5 Multi-year Interagency Program Recommendation Participating agencies Prepare a long term plan Define appropriate agency roles Share funding, staff, and other resource commitments Share user benefits

6. 6 Status NOAA/NASA partnership since 2000 Guided by GTWS Executive Steering Committee (GESC) Investigate data acquisition GESC action item to prepare this roadmap Data requirements OSSEs Requirements validation Benefit quantification Favorable preliminary benefit-to-cost ratios Reference instruments and missions Assess technology readiness Support evaluation of alternatives Preliminary cost estimates NASA Laser Risk Reduction Program (LRRP)

7. 7 Status (continued) Instrument activities NASA, NOAA, IPO and others demonstrating ground and airborne DWLs IPO funding airborne work on calibration/validation Related international missions Japanese National Space Development Agency (NASDA) European Space Agency (ESA)

8. 8 Status - Measurement Concept 7.7 km/s 400 km 585 km 414 km 290 km 45° 7.2 km/s Horizontal TSV Vertical resolution range gates 45 o nadir angle Scan through 8 azimuth angles Fore and aft perspectives in TSV Move scan position ~ 1 sec No. shots averaged ~ 5 sec * prf 4 ground tracks Aft perspective

9. 9 Status - Instrument Concepts Telescope with Sunshade Radiator Rotating Deck Coherent Direct Belt Drive Radiator Component Housing Component Boxes Note: Large solar arrays not shown

10. 10 Status - DWL Alternatives Each alternative has advantages Direct detection Coherent Hybrid Hybrid combines complementary aspects of coherent and direct detection Possibly the most rapid and economical approach May complicate mission and spacecraft issues IPO is sponsoring a hybrid DWL feasibility study

11. 11 Status -Reference Designs Need space-qualified DWL capable of meeting data requirements Coherent and direct detection reference designs completed Large and heavy spacecraft Massive optical components Very high electrical power consumption Hybrid Promising point design supported by IPO Reference design not completed

12. 12 Roadmap - Near Term Issues Technology development needed Lasers Detectors Low-mass telescopes Scanners Momentum compensation Benefits and sensitivity to data requirements Hybrid reference design DWL alternatives - trade studies Impacts on data products from atmospheric properties, DWL alternatives, and spacecraft mechanics Calibration and validation

13. 13 Roadmap Time scale depends on Funding and resource decisions Technology advances Longest lead time estimates Flight qualified lasers – 4 years Electro-optic scanners (alternative to rotating telescope scanners) – up to 6 years Laboratory, ground, air, and space demonstrations will reduce risk and cost

14. 14 Roadmap – Major Tasks and Phasing No time scale assigned pending planning decisions

15. 15 Roadmap – Task Descriptions 1. GESC Oversight- coordinate interagency support and management 2. Data Requirements and Data Utility Preparedness Benefits, sensitivity to data requirements Data assimilation Revised data requirements, if justified 3. Achieve Technology Readiness Lasers Detectors Low-mass telescopes Scanners Momentum compensation

16. 16 Roadmap – Task Descriptions (continued) 4. Architecture- system engineering and architecture for optimal design and acquisition, e.g. Trades between data requirements and technology Hybrid reference design Trades between DWL alternatives Atmosphere and lidar models Impacts on data products from atmospheric properties, DWL alternatives, and spacecraft mechanics Calibration and validation 5. Ground Demonstration- prototype DWLs

17. 17 Roadmap – Task Descriptions (concluded) 6. Air Demonstration Selected DWL approach Variety of atmospheric conditions 7. Space Demonstration Prove ability to meet data requirements from orbit Shuttle, International Space Station, DOD Space Test Program mission, or other platform 8. Operational Mission Acquire, launch, and operate end-to-end system Produce and distribute data products Orbit a second instrument, as required, to meet temporal and spatial resolution requirements

18. 18 Lower Level Roadmaps Technology DevelopmentDirect Detection Coherent Detection Hybrid Detection LaserXXX Optical FiltersXX PointingXXX Detectors and ArraysXX Photon EfficiencyXXX Tunable LO LaserXX AutoalignmentXX Hybrid Ref DesignsX Hybrid Integration DesignsX

19. 19 Roadmap - Preliminary Resource Estimates Cost estimates for internal government use Depend on a wide range of contingencies Inference from experience is not very accurate

20. 20 Roadmap – First Cut Fraction of Relative Cost by Task Fraction of total cost

21. 21 Summary and Recommendations Promising preliminary benefit to cost ratio Requires technology advances Architecture studies To drive future work Potential savings on development, space demonstration, and mission Interagency team Near term activities

22. 22 Farzin Amzajerdian (NASA/LaRC) Robert Atlas (NASA/GSFC) Wayman Baker (NOAA/NWS) James Barnes (NASA/LaRC) David Emmitt (Simpson Weather Associates) Bruce Gentry (NASA/GSFC) Ingrid Guch (NOAA/NESDIS) Michael Hardesty (NOAA/OAR) Michael Kavaya (NASA/LaRC) Stephen Mango (NPOESS/IPO) Kenneth Miller (Mitretek Systems) Steven Neeck (NASA/HQ) John Pereira (NOAA/NESDIS) Frank Peri (NASA/LaRC) Upendra Singh (NASA/LaRC) Gary Spiers (NASA/JPL) James G. Yoe (NOAA/NESDIS) Acknowledgments