Optical Autocovariance Wind Lidar (OAWL) Development Program

1. OAWL Progress and PlansChristian J. Grund, Bob Pierce, Jim Howell, and Carl WeimerBall Aerospace & Technologies Corp. (BATC), cgrund@ball.com1600 Commerce St. Boulder, CO 80303July 09, 2008

2. Optical Autocovariance Wind Lidar (OAWL) Development Program • Internal investment to develop the OAWL theory and implementable architecture, performance model, perform proof of concept experiments, and design and construct a flight path receiver prototype. • Recent NASA IIP win will take OAWL receiver at TRL-3, build into a robust lidar system, fly on the WB-57, exit at TRL-5.

3. OAWL Receiver IRAD Objectives • Design and fabricate a multi-wavelength, field-widened prototype optical autocovariance receiver suitable for high altitude aircraft demonstration of winds, HSRL, and depolarization measurements. • Develop optical assembly and alignment techniques suitable for adjustment free high resolution interferometry on flight systems. • Develop an integrated model for an OAWL receiver that predicts OAWL performance in thermal and vibration environments that can be used to lower riskfor a space qualified OAWL, OA-HSRL, and OA-DIAL designs.

4. OAWL Receiver Design Uses Polarization Multiplexing to Implement 4-OACF Phase-Delay Interferometers with the Same OPD • Mach-Zehnder-like interferometer allows 100% light detection on 4 detectors • Cat’s-eyes field-widen and preserve interference parity allowing wide alignment tolerance, practical simple telescope optics • Receiver is achromatic, facilitating simultaneous multi-l operations (multi-mission capable: Winds + HSRL(aerosols) + DIAL(chemistry)) • Very forgiving of telescope wavefront distortion saving cost, mass, enabling HOE optics for scanning and aerosol measurement • 2 input ports facilitating 0-calibration Ball Aerospace & Technologies patents pending

5. Solid Model of Receiver (detector covers removed) • - All aluminum construction minimizes DT, cost • - Athermal interferometer design • - Factory-set operational alignment • for autonomous aircraft operation • - ≈100% opt. eff. to detector • - multi-l winds, plus HSRL and depolarization for • aerosol characterization • and ice/water cloud • discrimination • - Compatible with wind and HSRL measurements Detectors: 1 532nm depolarization 1 355nm depolarization 4 532nm winds/HSRL 4 355nm winds/HSRL 10 Total Ball Aerospace & Technologies patents pending

6. Code V SolidWorks 6 NASTRAN Aircraft PSD Integrated Model Process Developed at BATC • Goals: • <6 nm (0.11 rad phase error) vibration induced noise), 12 nm accep. • <5% visibility reduction due to thermoelastic distortions. • Main system modeling outputs • Fringe visibility • Phase noise References: M. Lieber, C. Weimer, M. Stephens, R. Demara, “Development of a validated end-to-end model for space-based lidar systems”, in SPIE vol 6681, U.N.Singh, Lidar Remote Sensing for Environmental Monitoring VIII, Aug 2007. M. Lieber, C. Randall, L. Ayari, N. Schneider, T. Holden, S. Osterman, L. Arboneaux, "System verification of the JMEX mission residual motion requirements with integrated modeling", SPIE 5899, Aug 2005. M. Lieber, C. Noecker, S. Kilston, “Integrated system modeling for evaluating the coronagraph approach to planet detection”,  SPIE V4860, Aug 2002 Ball Aerospace & Technologies

7. Integrated Model – Design Iteration:Vibration-Induced Phase Noise Convergence on Specification 3.5 1900 nm, initial hard mount 3 8.5/ 6 nm, redesigned structure, WC/ nom 40/ 20 nm, 20 Hz isolators added, WC/ nom 2.5 2 Log OPD (nm) 1.5 Requirement: <1m/s/shot/100 ms Random dynamic error with WB-57 excitation 1 Final design Prediction Feb. 2008 : 6nm RMS jitter, exceeding spec and meeting goal, suggests performance dominated by intensity SNR, not vibration environment 0.5 0 1 2 3 4 5 WC = Worst case Thermal results: model verifies design is athermal wrt average temperature Ball Aerospace & Technologies

8. OAWL Receiver IRAD Progress – Major mechanical and optical components received • A few simple components • Detector housings • Monolithic interferometer • Covers and base plate • mount to a monolithic base structure. • Detector amplifiers and thermal controls • are housed inside the base structure. Ball Aerospace & Technologies

9. OAWL IIP Lidar System Objectives • Demonstrate OAWL wind profiling performance of a system designed to be directly scalable to a space-based direct detection DWL (i.e. to a system with a meter-class telescope 0.5J, 50 Hz laser, 0.5 m/s precision, with 250m resolution). • Raise TRL of OAWL technology to 5 through high altitude aircraft flight demonstrations. • Validate radiometric performance model as risk reduction for a flight design. • Demonstrate the robustness of the OAWL receiver fabrication and alignment methods against flight thermal and vibration environments. • Validate the integrated system model as risk reduction for a flight design. • Provide a technology roadmap to TRL7 Ball Aerospace & Technologies

10. Shake and Bake Receiver First light Ground Demo Flight Demo Road to TRL7 Internal Review Milestones IIP Program Elements and Schedule Ball Aerospace & Technologies

11. IIP System Concept for WB-57 Tests Pallet Cover 6’ Pallet (WB-57 form factor) Custom Pallet-Mounting Frame Telescope IRAD - Receiver Laser Source Custom Window Ball Aerospace & Technologies

12. IIP Test Plans • Ground Tests ~Fall 2009 • In Boulder, CO • Intercomparison with NOAA system (possibly HRDL) • Fixed pointing along a slant path • Airborne Testing • WB-57, 3 flight segments • Houston to Boulder, pick up many wind profilers • Multiple terrain backgrounds • Multiple cloud conditions • Racetrack Boulder and Platteville • NOAA Ground Lidar validation High resolution PBL winds • wind profiler whole atmosphere • Boulder to Houston, pick up wind profilers • Multiple terrain backgrounds • Ocean background and PBL • Multiple cloud conditions Boulder, CO Platteville, CO Houston, TX Ball Aerospace & Technologies

13. OAWL Receiver IRAD Progress Schedule and Status Receiver Status (Ball internal funding): • Optical design PDR complete Sep. 2007 • Receiver CDR complete Dec. 2007 • Receiver performance modeled complete Jan. 2008 • Design complete Mar. 2008 • COTS Optics procurement complete Apr. 2008 • Major component fabrication complete Jun. 2008 • Custom optics procurement complete Jun. 2008 • Assembly and Alignment in progress Aug. 2008 • Preliminary testing scheduledSep. 2008 Ball Aerospace & Technologies

14. Taking an OAWL Lidar System Through TRL 5 NASA Funded IIP Plan: • Program start, TRL 3 expected Jul. 2008 • Receiver shake and bake (WB-57 level) assume 7/1/08 start Oct. 2008 • Lidar system design/fab/integration “ Oct. 2009 • Ground Tests completed “ Mar. 2010 • Airborne tests completed TRL-5 “ Dec. 2010 • IIP Complete thru tech road mapping to TRL-7 “ May 2011 Ball Aerospace & Technologies

15. Conclusions • Optical Autocovariance Receiver IRAD is on-track to final assembly and test in September 2008. So far, so good. • Optical Autocovariance Lidar is on a path to TRL 5 in 2010 thanks to NASA IIP award. • IIP science advisory board partially assembled. Mike Hardesty and Bruce Gentry so far. Intend a third member, probably from University, TBD. • Ground testing in late Fall 2009 along side NOAA lidar (possibly HRDL) • Airborne testing from WB-57 in Fall 2010. • Possible multi-l co-validation of HSRL during IIP. Proposal in progress to leverage this element to the IIP (non-interference basis). Ball Aerospace & Technologies