1. Early VALIDAR Case Study Results Rod Frehlich: RAL/NCAR Grady Koch: NASA Langley

2. Doppler Lidar Properties Direct measurement of Doppler shift from aerosol particles Accurate radial velocity estimates with little bias Most sensitive detection method Immune to background light Eye safe operation

3. NASA LANGLEY LIDAR Grady Koch and Michael Kavaya System testbed for advanced high-energy lasers and optical components for future airborne and spaceborne Doppler lidars. Serve as ground-based test bed validation source for future airborne and spaceborne lidar measurements Test advanced receiver and processing components.

4. Lidar Parameters Laser material: Ho:Tm:LuLiF Wavelength = 2053.5 nm Pulse energy = 95 mJ Pulse width = 180 ns Pulse repetition rate = 5 Hz Telescope aperture = 6 inches

5. Motivation Observe clear air conditions in front of approaching convective storms at Langley Vertical stare to maximize altitude Extract quantitative turbulence metrics for verification

8. Boundary Layer Turbulence Best-fit structure function Height 588-2412 m Time 0.01-0.99 Low turbulence Typical length scale L 0

9. Cirrus Cloud Turbulence Best-fit structure function Height 13.2-13.8 km Time 0.44-0.89 Low turbulence Well-defined length scale L 0

11. Free Tropospheric Turbulence Best-fit structure function Height 840-3900 m Time 0.01-0.68 Low turbulence Large length scale L 0

12. Cirrus Cloud Turbulence Best-fit structure function Height 10.2-11.2 km Time 0.11-0.67 Low turbulence Small length scale L 0

13. SUMMARY Lidar can extract quantitative turbulence statistics Higher altitude turbulence only available inside cirrus and other high backscatter regions More signal required for reliable verification data above 5 or 6 km More theoretical predictions of turbulence statistics required