Development of a Compact, Pulsed, 2-Micron, Coherent- Detection, Doppler Wind Lidar Transceiver

Transcription

1 Development of a Compact, Pulsed, 2-Micron, Coherent- Detection, Doppler Wind Lidar Transceiver Michael J. Kavaya, Upendra N. Singh, Grady J. Koch, Jirong Yu, Bo C. Trieu NASA Langley Research Center, Hampton, Virginia USA Mulugeta Petros Science and Technology Corporation Paul J. Petzar National Institute of Aerospace Coherent Laser Radar Conference Toulouse, France June 23, 2009

2 Acknowledgments Grady J. Koch NASA LaRC Co-I, overall lidar system lead, field demonstration, receiver Jirong Yu NASA LaRC Co-I, pulsed transmitter laser lead Bo C. Trieu NASA LaRC Co-I, mechanical and thermal engineering Jeffrey Y. Beyon NASA LaRC Data acquisition HW & SW Upendra N. Singh NASA LaRC Co-I, pulsed transmitter laser Carl S. Mills/Paul J. Petzar NASA LaRC/NIA Electronic design & fabrication G. David Emmitt SWA Airborne Doppler lidar, pointing knowledge Michael J. Kavaya NASA LaRC Principal Investigator Garfield A. Creary NASA LaRC Project manager John Cox SSAI Management consultant Ramesh K. Kakar/George J. Komar/Janice L. Buckner NASA ESD/ESTO Guidance & Funding

3 Motivation for 2-Micron Laser/Lidar Development NRC Recommended 3-D Winds Mission NRC Decadal Survey Global Winds 9 Societal Benefits Extreme Weather Warnings Human Health Earthquake Early Warning Improved Weather Prediction #1 Sea-Level Rise Climate Prediction Freshwater Availability Ecosystem Services 2007 Air Quality 3

4 Multiple Aspects of 2-Micron Laser/Lidar Advancement at NASA/LaRC Laser Physics Material Physics Laser Architecture Pump Laser Diodes Pulse Energy Pulse Repetition Frequency Pulse Length Pulse Spectral Width Beam Quality Electrical Efficiency Conductive Cooling Compact Packaging Lidar Telescope Lidar Scanner Data Acquisition Data Processing Ground Demonstration Intercomparison Airborne Demonstration Autonomous Operation Laser Lifetime Space Qualifiable Brassboard Space Qualification past future

5 Doppler Aerosol WiNd lidar (DAWN) Compact Engineered Coherent Doppler Lidar Transceiver Propagation Path (Atmosphere) Target (Atmospheric Aerosols) Lidar System Laser & Optics Scanner Telescope Pulsed Transmitter Laser (includes CW injection laser) Detector/Receiver (may include 2nd CW LO laser) Polarizing Beam Splitter Transceiver λ/4 Plate Laser Chillers Electronics (Power Supplies, Controllers) Computer, Data Acquisition, and Signal Processing (including software)

6 DAWN Results Smaller More energy More robust DAWN Transceiver (Transmitter + Receiver) 250 mj/pulse, 10 pulses/sec. 5.9 x 11.6 x 26.5, 75 lbs.; 15 x 29 x 67 cm, 34 kg (no telescope or scanner) 5.9 x 11.6 x 26.5 Previous implementation 90 mj per pulse Completed DAWN package Small, Robust, 250 mj per pulse

7 DAWN Transceiver vs. Commercial Doppler Lidar Commercial Doppler Lidar LaRC DAWN 2 microns, 2 mj, 500 Hz, 10 cm telescope 111 x 85 x 102 H inches, > $1 M 2 microns, 250 mj, 5 Hz, 15 cm telescope Transceiver: 6 x 12 x 27 inches, 75 lbs DAWN vs. COTS Unit Wind figure of merit = E x PRF x D 2 Energy gain = x125 Energy-PRF gain = x13 Energy-PRF-diameter gain = x26 Either x26 in aerosol backscatter sensitivity or x5 in range

8 DAWN Wind Measurement Performance sonde of February 24, 2009 at 17:59 local Error Tree Lidar +Sonde +Location +Time +M Volume +M Time Int. =Total Error altitude (m) VALIDAR (3-minute integration) sonde wind speed (m/s) altitude (m) sonde speed - VALIDAR speed (m/s) 7000 root-mean-square of difference between two sensors for all points shown = 1.06 m/s altitude (m) VALIDAR (3-minute integration) sonde altitude (m) root-meansquare of difference between two sensors for all points shown = 5.78 deg wind direction (degrees) sonde direction - VALIDAR direction (degrees)

9 Current Work in Progress DAWN-AIR1: Utilize DAWN Transceiver to develop a complete Doppler lidar system for the DC-8 airplane No flights included DAWN-AIR2: Utilize DAWN-AIR1 hardware and convert to operation on the higher altitude WB-57 airplane Upgrade hardware to autonomous operation Demonstration flights Fly with NASA GSFC direct detection Doppler wind lidar system

10 DAWN-AIR1 Approach 1. Add telescope and scanner to DAWN 2. Ruggedize electronics for DC-8 Propagation Path (Atmosphere) Target (Atmospheric Aerosols) Lidar System Laser & Optics Scanner Telescope Pulsed Transmitter Laser (includes CW injection laser) Detector/Receiver (may include 2nd CW LO laser) Polarizing Beam Splitter Transceiver λ/4 Plate DAWN Transceiver (Transmitter + Receiver) 250 mj/pulse, 10 pulses/sec. 5.9 x 11.6 x 26.5, 75 lbs.; 15 x 29 x 67 cm, 34 kg (no telescope or scanner) Laser Chillers Electronics (Power Supplies, Controllers) Computer, Data Acquisition, and Signal Processing (including software)

11 DAWN-AIR 1 Artist Concept 30 deg nadir angle Any azimuth angle

12 DAWN-AIR1 Lidar Sealed Enclosure Contains: DAWN Transceiver Telescope Scanner & Wedge Vibration Isolation As shown with both the 30deg and 45deg cone

13 DAWN-AIR2 Approach Propagation Path (Atmosphere) Target (Atmospheric Aerosols) Lidar System Laser & Optics Scanner Telescope Pulsed Transmitter Laser (includes CW injection laser) Detector/Receiver (may include 2nd CW LO laser) Laser Chillers Electronics (Power Supplies, Controllers) Polarizing Beam Splitter Transceiver λ/4 Plate Computer, Data Acquisition, and Signal Processing (including software) 2 3-ft pallets 45 deg nadir angle Any azimuth angle

14 Conclusions Working with NASA LaRC developed 2-micron laser technology that has demonstrated 1.2 J pulse energy Compact, engineered transceiver at 250 mj, 5 Hz has successfully proven wind measurement and robustness Now developing lidar systems using this transceiver for DC-8 and WB-57 aircraft Have proposed to fly in NASA SMD ESD hurricane Genesis and Rapid Intensification Program (GRIP) in summer 2010 Desire to continue technology advancement for 3-D Winds space mission