1. Wind Lidar Working Group, 29 June 2005 Welches, OR Doppler Lidar Scanning Telescope Technology Geary Schwemmer Meeting of the Working Group on Space-based Lidar Winds Welches, Oregon June 28- July 1, 2005

2. Wind Lidar Working Group, 29 June 2005 Welches, OR Topics Requirements Constraints Approaches Comparisons Roadmaps

3. Wind Lidar Working Group, 29 June 2005 Welches, OR Requirements Narrow field of view Large collecting area Large off-nadir scan angles (~30-50°) Step-stare preferred over continuous scanning Rapid slew 2 ~orthogonal looks into each sample volume Laser bore-sighting

4. Wind Lidar Working Group, 29 June 2005 Welches, OR Constraints Volume Mass Power Vibration Torque Momentum compensation Space environment

5. Wind Lidar Working Group, 29 June 2005 Welches, OR Approaches Conventional telescope w/ rotating mount Multiple telescopes Scanning flat mirror Rotating wedge prism Rotating Fresnel prism Rotating HOE Multiplexed HOE / SHADOE

6. Wind Lidar Working Group, 29 June 2005 Welches, OR Comparisons Mass and Power comparisons. (Source - GSFC Doppler Lidar Technology assessment, 2001.) System Total MassTotal Avg. Power Rotating SiC 1.25 m reflective telescope 302 kg260 W Scanning flat mirror>450 kg Rotating Fresnel wedge >450 kg Rotating 1.5-m HOE152 kg130 W 1.5-m ShADOE65 kg 20 W

7. Wind Lidar Working Group, 29 June 2005 Welches, OR Holographic Optics IR

8. Wind Lidar Working Group, 29 June 2005 Welches, OR Hybrid SHADOE Roadmap TRL5 TRL4 TRL3

9. Wind Lidar Working Group, 29 June 2005 Welches, OR Key Remaining Issues Space qualification 2-micron performance (diffraction limited) SHADOE demonstration System trades: –laser –# of FOVs & dwell time / spatial resolution –hybrid configuration Scaling to  1 meter

10. Wind Lidar Working Group, 29 June 2005 Welches, OR Conclusions Conventional scanning telescope too heavy 2-micron & 355 nm requirements very different (size & image quality), perhaps equally difficult HOE technologies offer significant weight and power savings for large apertures Perhaps the lowest TRL of UV Doppler components No show stoppers, but significant risk & development

11. Wind Lidar Working Group, 29 June 2005 Welches, OR 150° Baseline Scan Configuration Satellite nadir ground track Y A = 324 km Y B = 87 km 30° Z = 400 km,  = 40°,  A = 75°,  B = 15°,  C = 45° Y C = 237 km 90° 324 km 237 km 3 tracks, 6 lines of sight 0 90 seconds timing 1278 33 57

12. Wind Lidar Working Group, 29 June 2005 Welches, OR Optical Layout (single HOE)

13. Wind Lidar Working Group, 29 June 2005 Welches, OR UV-A exposure effects

14. Wind Lidar Working Group, 29 June 2005 Welches, OR Wavefront Error Correction Wave-front corrective prescription applied to cover glass Wave-front distortion caused by HOE materials

15. Wind Lidar Working Group, 29 June 2005 Welches, OR Hybrid R-T Combination SHADOE Receiver (One FOV shown) UV Reflection SHADOE IR Transmission SHADOE IR Focal Plane UV Focal Plane