Science Definition Team Activities and the GTWS Draft Data Requirements

1. Science Definition Team Activities and the GTWS Draft Data Requirements Jim Yoe, NOAA/NESDIS/ORA James.G.Yoe@noaa.gov Bob Atlas, NASA/GSFC/DAO Atlas@dao.gsfc.nasa.gov Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

2. Overview • The SDT and its role wrt GTWS • Goals, approach, and actions for 2001 • The Product: Draft Data Requirements • Initial Applications of Draft Requirements • Next Steps Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

3. SDT Role and Composition • GTWS joint NASA/NOAA effort • “Pre-formulated” as a data buy; to be Useful Achievable (or “doable” in Agencyese Affordable • SDT to identify/address science issues • NOAA, NASA, and universities represented Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

4. The Process • Requirements Workshop February 2001 • SDT plus other scientists, engineers, managers, and industry representatives • Input compiled/organized by “Gang of 3” • Atlas, Emmitt, Yoe • SDT Meeting in July 2001 • Begin reconciliation and consensus process • Set up some last minute analysis - RROSSEs • Draft Released for Public Comment October 15 2001 Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

5. GTWS Wind Data Product Requirements Threshold Objective Depth of Regard (DOR) (km) 0-20 0-30 Vertical Target Sample Volume (TSV) Resolution (km) Top of DOR to Tropopause Tropopause to boundary layer top Within boundary layer Not Required 1 0.5 2 0.5 0.25 Height Assignment Accuracy (km) 0.1 0.1 Horizontal TSV Dimension (km) (maximum for averaging) 100 25 Horizontal Location Accuracy (km) 0.5 0.5 Horizontal Resolution (km) (distance between TSVs) 350 100 Minimum X-track Regard (km) (Number in () is number of TSVs) +/- 400 (4) +/- 625 (12) Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

6. Requirement Threshold Objective Number Line of Sight (LOS) perspectives in TSV (angular separation >30 & <150) 2 2 Accuracy (1) LOS Horiz (LOSH) (m/s) Above Boundary Layer Within Boundary Layer (number in () is S within TSV) 3 (1.2) 3 (1.2) 2 (1.4) 1 (1) Horizontal Component Bias (m/s) 0.1 0.05 Maximum Horizontal Speed (m/s) Above boundary layer Within Boundary layer 75 50 100 50 Temporal Resolution (hours) (revisit period) 12 6 Data Product Latency (hours) 2.75 2.75 Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

7. GTWS Draft Requirements Requirements to be satisfied taking into account • Nominal Cloud Coverage • Reference Target Atmospheres Other Requirements • Orbital coverage from 80 S to 80 N (min) • All raw data to be downlinked • Two-year minimum mission life Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

8. Feedback Summary • Comments were received • From industry, universities & government agencies • Generally positive • Users confident of potential for benefit • Industry instrument builders encouraged that thresholds more achievable than previous • (Lidar) Technological neutrality • Specific suggestions • Some objections, recommendations, requests for clarification, and some revision (relaxation) Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

9. Next Steps • Public Forum for Comments on Date, venue, and format TBD • Follow-up SDT meeting • Continued numerical experiments, analysis • Consider additional input • DoD requirements beyond current IORD • Revise specifications as appropriate Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

10. Next Steps (continued) • Develop Validation Plan • Need SDT and TAT to collaborate • Complete and publish documentation • Workshop Executive Summary & Minutes • Requirements Crosswalk Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas

11. Continuing Numerical Experiments • NCEP OSSEs • Bracketing OSSEs for forecasts becoming available • Implications • NASA/DAO OSSEs • Atlas Described NCAR/NASA NR in July • Now getting first forecast results • Full Profiles Everywhere • 1 m/s rms errors • NH & SH get “twice impact of all other satellite data” • “RROSSEs: Lidar Winds Working Group Meeting GTWS SDT-Yoe & Atlas